Generac Power Systems Portable Generator 941 2 User Manual

Manual Part No. 0D9057  
SERVICE  
MANUAL  
SERIES IMPACT 36 PLUS II  
Models 940-2 & 941-2  
P.O. Box 297 • Whitewater, WI • 53190  
Phone: (262) 473-5514  
Fax: (262) 472-6505  
Printed in U.S.A  
Revision A - 07/15/03  
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TABLE OF CONTENTS  
PART  
1
TITLE  
THE AC GENERATOR  
SERVICE  
MANUAL  
2
3
4
5
6
7
8
ENGINE MECHANICAL  
GASOLINE FUEL SYSTEM  
GASEOUS FUEL SYSTEM  
ENGINE OIL & COOLING SYSTEM  
ENGINE ELECTRICAL SYSTEM  
TROUBLESHOOTING  
SERIES IMPACT 36 PLUS II  
SPECIFICATIONS & CHARTS  
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SECTION  
1.1  
TITLE  
GENERATOR FUNDAMENTALS  
PART 1  
GENERAL  
INFORMATION  
1.2  
1.3  
1.4  
1.5  
1.6  
1.7  
GENERATOR MAJOR COMPONENTS  
OPERATIONAL ANALYSIS  
INSULATION RESISTANCE  
COMPONENTS TESTING  
CONTROL PANEL  
COMPUTER  
CONTROLLED  
VARIABLE  
SHEET METAL  
SPEED RV  
GENERATORS  
Series Impact 36 Plus II  
Page 1  
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NOTES  
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Section 1.1  
GENERATOR FUNDAMENTALS  
NOTE: The "right hand rule" is based on the "cur-  
rent flow" theory which assumes that current  
flows from positive to negative. This is opposite  
the "electron" theory, which states that current  
flows from negative to positive.  
MAGNETISM  
Magnetism can be used to produce electricity and  
electricity can be used to produce magnetism.  
Much about magnetism cannot be explained by our  
present knowledge. However, there are certain pat-  
terns of behavior that are known. Application of these  
behavior patterns has led to the development of gen-  
erators, motors and numerous other devices that uti-  
lize magnetism to produce and use electrical energy.  
See Figure 1. The space surrounding a magnet is  
permeated by magnetic lines of force called "flux".  
These lines of force are concentrated at the magnet's  
north and south poles. They are directed away from  
the magnet at its north pole, travel in a loop and re-  
enter the magnet at its south pole. The lines of force  
form definite patterns which vary in intensity depend-  
ing on the strength of the magnet. The lines of force  
never cross one another. The area surrounding a  
magnet in which its lines of force are effective is  
called a "magnetic field".  
Like poles of a magnet repel each other, while unlike  
poles attract each other.  
Figure 2. The Right Hand Rule  
ELECTROMAGNETIC INDUCTION  
An electromotive force (EMF) or voltage can be pro-  
duced in a conductor by moving the conductor so that  
it cuts across the lines of force of a magnetic field.  
Similarly, if the magnetic lines of force are moved so  
that they cut across a conductor, an EMF (voltage)  
will be produced in the conductor. This is the basic  
principal of the revolving field generator.  
Figure 3, below, illustrates a simple revolving field  
generator. The permanent magnet (Rotor) is rotated  
so that its lines of magnetic force cut across a coil of  
wires called a Stator. A voltage is then induced into  
the Stator windings. If the Stator circuit is completed  
by connecting a load (such as a light bulb), current  
will flow in the circuit and the bulb will light.  
Figure 1. Magnetic Lines of Force  
ELECTROMAGNETIC FIELDS  
All conductors through which an electric current Is  
flowing have a magnetic field surrounding them. This  
field is always at right angles to the conductor. If a  
compass is placed near the conductor, the compass  
needle will move to a right angle with the conductor.  
The following rules apply:  
• The greater the current flow through the conductor,  
the stronger the magnetic field around the conductor.  
• The increase in the number of lines of force is  
directly proportional to the increase in current flow  
and the field is distributed along the full length of  
the conductor.  
• The direction of the lines of force around a conduc-  
tor can be determined by what is called the "right  
hand rule". To apply this rule, place your right hand  
around the conductor with the thumb pointing in the  
direction of current flow. The fingers will then be  
pointing in the direction of the lines of force.  
Figure 3. A Simple Revolving Field Generator  
Page 1.1-1  
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Section 1.1  
GENERATOR FUNDAMENTALS  
Figure 4. Operation of a Simple Generator  
mum negative value. Two reversals of current flow is  
called a cycle. The number of cycles per second is  
called frequency and is usually stated in "Hertz".  
ALTERNATING CURRENT  
A simple generator consists of a coil of wires called a  
Stator and a magnetic field called a Rotor. As the  
Rotor's magnetic field cuts across the Stator coil, a  
voltage is induced into the Stator windings. The  
amount of induced voltage is equal to the strength of  
the magnetic field.  
See Figure 4. The current alternates according to the  
position of the Rotor's poles in relation to the position  
of the Stator. At 0° and again at 180°, no current flow  
is produced. At 90° of Rotor rotation, current flow  
reaches a maximum positive value. Rotor rotation to  
270° brings another maximum flow of current.  
However, at 270° the current flow has reversed in  
polarity and now flows in the opposite direction.  
ELECTRICAL UNITS  
Figure 5. Alternating Current Sine Wave  
VOLT:  
The VOLT is the unit used to measure electrical  
PRESSURE, or the difference in electrical potential  
that causes electrons :o flow. Very few electrons will  
flow when voltage is weak. More electrons will flow as  
voltage becomes stronger. VOLTAGE may be consid-  
ered to be a state of unbalance and current flow as  
an attempt to regain balance. One volt is the amount  
of EMF that will cause a current of 1 ampere to flow  
through 1 ohm of resistance.  
AMPERE:  
The rate of electron flow in a circuit is represented by  
the AMPERE. The ampere is the number of electrons  
flowing past a given point at a given time. One  
AMPERE is equal to just slightly more than six thou-  
sand million billion electrons per second.  
With alternating current (AC), the electrons flow first  
in one direction, then reverse and move in the oppo-  
site direction. They will repeat this cycle at regular  
intervals. A wave diagram, called a "sine wave"  
shows that current goes from zero to maximum posi-  
tive value, then reverses and goes from zero to maxi-  
Page 1.1-2  
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Section 1.1  
GENERATOR FUNDAMENTALS  
If OHMS is unknown but VOLTS and AMPERES are  
known, use the following:  
VOLTS  
AMPERES  
=
OHMS  
REACTANCE IN AC CIRCUITS  
GENERAL:  
When direct current (DC) is flowing, the only opposi-  
tion to current flow that must be considered is resis-  
tance (ohms). This is also true of alternating current  
(AC) when only resistance type loads such as heating  
and lamp elements are on the circuit. In such a case,  
current will be in phase with voltage- that is, the cur-  
rent sine wave will coincide in time with the voltage  
sine wave.  
Figure 6. Electrical Units  
However, two factors in AC circuits called INDUC-  
TIVE and CAPACITIVE REACTANCE will prevent the  
voltage and current sine waves from being in phase.  
OHM:  
The OHM is the unit of RESISTANCE. In every circuit  
there is a natural resistance or opposition to the flow  
of electrons. When an EMF is applied to a complete  
circuit, the electrons are forced to flow in a single  
direction rather than their free or orbiting pattern. The  
resistance of a conductor depends on (a) its physical  
makeup, (b) its cross-sectional area, (c) its length,  
and (d) its temperature. As the conductor's tempera-  
ture increases, its resistance increases in direct pro-  
portion. One (1) ohm of resistance will permit one (1)  
ampere of current to flow when one (1) volt of electro-  
motive force (EMF) is applied.  
INDUCTIVE REACTANCE:  
This condition exists when current lags behind volt-  
age (Figure 8). As current flows in a circuit, magnetic  
lines of force are created at right angles to the con-  
ductor. The continuous changes in current value  
(from positive to negative) cause these magnetic lines  
to collapse and build up continuously.  
The magnetic field around the conductor induces  
electromotive forces that cause current to keep on  
flowing while voltage drops. The result is a condition  
in which voltage leads current. When a conductor is  
formed into a coil, the magnetic lines of force are con-  
centrated in the center of the coil. This increased den-  
sity causes an increase in magnetically Induced EMF  
without increasing current Thus, coils cause inductive  
reactance.  
OHM'S LAW  
A definite and exact relationship exists between  
VOLTS, OHMS and AMPERES. The value of one can  
be calculated when the value of the other two are  
known. Ohm's Law states that in any circuit the current  
will increase when voltage increases but resistance  
remains the same, and current will decrease when  
resistance Increases and voltage remains the same.  
Inductive reactance can also be caused by placing an  
induction motor on the circuit which utilizes the cur-  
rent's magnetic field for excitation.  
Figure 7.  
If AMPERES is unknown while VOLTS and OHMS  
are known, use the following formula:  
VOLTS  
OHMS  
AMPERES =  
Figure 8. Inductive Reactance  
If VOLTS is unknown while AMPERES and OHMS  
are known, use the following formula:  
VOLTS = AMPERES x OHMS  
Page 1.1-3  
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Section 1.1  
GENERATOR FUNDAMENTALS  
CAPACITIVE REACTANCE:  
trolled by the inverter and is maintained at a steady  
60 Hz signal throughout the load range.  
Computer controlled generator units have the ability  
to operate the engine over a wide range of speeds,  
while conventional generators will deliver correct AC  
frequency and voltage only at a fixed rpm.  
Unlike conventional AC generators, the Impact Plus  
unit can match engine speed to load requirements.  
This provides several advantages, as follows:  
This condition occurs when current leads voltage  
(Figure 9). It might be thought of as the ability to oppose  
change in voltage. Capacitance exists in a circuit when  
certain devices are ~a) capable of storing electrical  
charges as voltage increases and (b) discharging these  
stored charges when the voltage decreases.  
• Smaller engines can be used to produce more  
power than on a conventional generator, since it  
can be allowed to run at a higher speed.  
• When the load is reduced, the engine can run at  
slower than the usual speeds. This improves fuel  
economy and reduces engine noise.  
• The Impact Plus unit can be operated closer to its  
peak power point at all times, because output volt-  
age and current are functions of engine speed. This  
allows for a much more compact generator design.  
IMPACT PLUS SYSTEM OVERVIEW:  
Figure 10 is a block diagram of the Impact Plus sys-  
tem. The major elements of the system are represent-  
ed in the diagram. Operation of the system may be  
described briefly as follows:  
Figure 9. Capacitive Reactance  
WHAT IS AN "IMPACT PLUS" UNIT?:  
1. The engine is directly coupled to a permanent magnet type  
Rotor, so the Rotor runs at the same speed as the engine.  
The Impact Plus is a computer controlled generator  
that uses an inverter to create a superior sine wave  
and maintain a steady frequency. These units are dif-  
ferent from conventional generators in that the perfor-  
mance of the engine and AC generator are more  
accurately matched over a wide range of power  
needs. The Impact Plus computer controlled genera-  
tor provides greater efficiency of both the engine and  
the generator while maintaining electrical output with-  
in an acceptable voltage range. The frequency is con-  
2. As the Rotor turns, its magnetic field cuts across the Stator  
windings to induce a voltage into the Stator.  
Figure 10. Block Diagram of the Impact 36 Plus System  
Page 1.1-4  
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Section 1.1  
GENERATOR FUNDAMENTALS  
3. When the generator circuit breaker is turned to the “ON” position,  
AC voltage is delivered to the Full Bridge Rectifier. The AC volt-  
age is rectified to DC and thus becomes DC Link voltage.  
WHY VARIABLE SPEED CONTROL?  
Most electrical loads will operate satisfactorily only  
within a relatively small voltage band. In order to pro-  
vide useful voltage at larger load currents, it is neces-  
sary to increase engine speed.  
4. AC voltage from the stator PS1/PS2 is delivered to the inverter.  
This is used as the power supply for the inverter circuit board.  
In conventional AC generators, some form of voltage  
regulation is needed to provide correct voltage in the  
full range of load current. This is often accomplished  
by regulating excitation current to the Rotor (field)  
which then regulates the strength of the Rotor's mag-  
netic field. The voltage induced into the Stator wind-  
ings is proportional to the strength of the Rotor's mag-  
netic field.  
The Impact Plus computer controlled generator uses  
a Rotor having a fixed and permanent magnetic field.  
The strength of this magnetic field is fixed and cannot  
be regulated.  
5. AC voltage from the stator TIM1/TIM2 is delivered to the system  
controller. This is used for engine speed sensing.  
6. The system controller sends signals to the inverter for inverter  
operation.  
7. The system controller senses load voltage and signals stepper  
motor operation to achieve required engine speed for correct  
voltage output.  
The output voltage on Impact Plus computer con-  
trolled generators tends to droop with increasing elec-  
trical loads. The SYSTEM CONTROLLER maintains  
a constant AC output voltage by increasing engine  
and Rotor speed as the load current increases, to off-  
set this inherent voltage droop.  
Page 1.1-5  
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Section 1.1  
GENERATOR FUNDAMENTALS  
Page 1.1-6  
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Section 1.2  
MAJOR GENERATOR COMPONENTS  
INTRODUCTION  
UPPER FAN HOUSING  
Major components of the generator proper are shown  
in Figure 1, below. External sheet metal and other  
unrelated components are omitted from the drawing  
for clarity. These parts are:  
As its name implies, this component houses and  
shields the upper cooling fan. See Figure 1, Item 1.  
UPPER COOLING FAN  
Item  
1
Description  
The Cooling Fan draws air into the generator through  
slots in the Upper Fan Housing. It is fastened to and  
rotates with the Permanent Magnet Rotor.  
Upper Fan Housing  
Upper Cooling Fan  
Permanent Magnet Rotor  
Rotor Hub  
2
3
4
5
Stator Retaining Ring  
Stator Assembly  
Stator Adapter  
Engine  
Lower Fan & Flywheel  
Stepper Motor  
PERMANENT MAGNET ROTOR  
6
7
Sixteen permanent magnets have been affixed to the  
Rotor. A starter ring gear is welded to the Rotor. The  
Rotor and Hub are balanced at the factory as an  
assembly and must be replaced as an assembly.  
8
9
10  
NOTE: The hub MUST be properly aligned during  
reassembly. The mounting bolt, housing opening  
and magnet must be properly aligned. In addition,  
match marks between the Hub and Rotor must be'  
aligned as indicated by an "ALIGN MARKS FOR  
BALANCE" decal. During assembly, use care to  
avoid damage to the Ignition Sensor.  
DANGER! The permanent magnet rotor pro-  
duces an extremely strong magnetic force.  
Use care during installation to avoid pinched  
!
fingers.  
Figure 1. Exploded View of Generator Proper  
Figure 2 Permanent Magnet Rotor Assembly  
Page 1.2-1  
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Section 1.2  
MAJOR GENERATOR COMPONENTS  
ROTOR HUB  
STEPPER MOTOR  
See Figure 2 on previous page. The Rotor Hub is bal-  
anced with the Rotor and must be replaced with the  
Rotor as an assembly. Part of the engine ignition sys-  
tem is pressed onto the Hub and can be replaced  
only as part of the Rotor and Hub assembly.  
The Stepper Motor (Figure 3) consists of a stepper  
motor along with a gear and cam arrangement which  
allows motor movement to change the engine carbu-  
retor throttle setting. The Motor is controlled by output  
signals from the Computer Control Circuit Board,  
which calculates the number of steps the stepper  
needs to take and generates the required signals to  
the Motor. The circuit board signals the Motor to actu-  
ate in response to changes in AC output voltage.  
Thus, in response to decreasing AC output voltages,  
the Motor will increase the throttle setting and engine  
speed will increase. Conversely, Increasing AC out-  
put voltages will cause the Motor to decrease throttle  
setting and engine speed will decrease.  
STATOR RETAINING RING  
The Stator Retaining Ring is made of die-cast alu-  
minum. Four hex head capscrews with lockwashers  
pass through holes in the Retaining Ring, to retain  
the Stator Assembly to the Stator Adapter (Item 7,  
Figure 1).  
STATOR ASSEMBLY  
The 2-phase Stator is made up of six (6) windings,  
with leads brought out as shown in figure 4. Figure 5  
is a schematic representation of each stator winding.  
Note that there are two (2) power phase windings  
(Leads AC1, AC2, SL1 and SL2 ); a timing winding  
(Leads TIM1 and TIM2); a power supply winding  
(Leads PSI, PS2); and a dual battery charge winding  
(Leads 55, 66, 77).  
STATOR ADAPTER  
The Adapter is retained to the engine by means of  
four hex head capscrews. The Stator is retained to  
the Stator Adapter and is "sandwiched" between the  
Adapter and the Stator Retaining Ring.  
LOWER FAN & FLYWHEEL  
Figure 3. The Stepper Motor  
The Lower Fan and Flywheel are retained to the  
engine PTO shaft by means of a conical washer and  
an M16-1.50 hex nut. When assembling, tighten the  
flywheel nut to 75 foot-pounds.  
ENGINE  
The engine is a single cylinder, 220 cc, overhead  
valve type manufactured by Generac® Power  
Systems, Inc.  
Figure 4. Stator Pictorial View  
Page 1.2-2  
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Section 1.2  
MAJOR GENERATOR COMPONENTS  
Figure 5. Schematic- Stator Windings  
Page 1.2-3  
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Section 1.2  
MAJOR GENERATOR COMPONENTS  
Page 1.2-4  
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Section 1.3  
OPERATIONAL ANALYSIS  
b.The STATOR POWER SUPPLY WINDING with  
output leads PS1-PS2.  
GENERAL  
Figure 1, below, is a block diagram of the Impact Plus  
computer controlled RV generator. The diagram is  
Intended only for the purpose of illustrating generator  
operation. Refer to the actual wiring diagram for  
wiring interconnections.  
c. The STATOR TIMING WINDING (output leads  
TIM1-TIM2).  
d.STATOR BATTERY CHARGE WINDING with  
output leads 55, 66 and 77.  
3. STATOR BATTERY CHARGE WINDING output is delivered to  
the unit battery via a BATTERY CHARGE RECTIFIER (BCR)  
and a 1 OHM, 50 WATT RESISTOR. The circuit is completed  
through the battery to frame ground and back to the BATTERY  
CHARGE WINDING via Wire 55.  
OPERATIONAL DESCRIPTION  
1. The Impact Plus is a computer controlled generator that uses  
an inverter to create a superior sine wave and maintain a  
steady frequency of 60 Hz. The PERMANENT MAGNET  
ROTOR is directly coupled to the ENGINE and rotates at the  
same speed as the engine.  
4. Stator timing winding output is delivered to the A6060 circuit  
board. The timing winding output is used to determine engine rpm.  
5. The stator power supply winding output is delivered to the  
inverter. This is the power supply for operation of the inverter.  
2. As the ROTOR turns, its magnetic field cuts across a number  
of STATOR windings, to induce a voltage into those windings.  
A voltage is induced into the following STATOR windings:  
6. Stator power winding output (phase 1 and 2) is delivered to two  
separate bridge rectifiers, where it is rectified to DC. This  
becomes the DC link voltage and is delivered to the inverter.  
a.Phase 1 and 2 of the STATOR POWER WIND-  
INGS (output leads AC1-AC2 and SL1-SL2).  
Figure 1. Block Diagram- A Generator System  
Page 1.3-1  
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Section 1.3  
OPERATIONAL ANALYSIS  
OPERATIONAL DESCRIPTION (CONTINUED)  
7. The A6060 circuit board controls all functions of the generator,  
i.e.:  
a.Engine DC control system  
b.Stepper motor operation  
(1) If voltage is low, the board will signal a  
STEPPER MOTOR to change engine throt-  
tle setting and increase speed until the  
desired voltage level is reached.  
(2) If voltage goes high, the board will signal  
the STEPPER MOTOR to reduce engine  
throttle setting until the desired voltage level  
is obtained.  
c. Output signals for operation of inverter.  
Page 1.3-2  
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Section 1.4  
INSULATION RESISTANCE  
CAUTION! When using a Megohmmeter or  
any other tester, be sure to follow the manu-  
facturer's instructions carefully. All Stator  
leads must be isolated from other compo-  
nents, especially circuit boards, before per-  
forming tests. The high voltages used in test-  
ing insulation resistance will damage elec-  
tronic components.  
DIRT AND MOISTURE  
!
If moisture is permitted to remain in contact with the  
generator Stator windings, some of it will be retained  
in voids and cracks of the winding insulation. This can  
eventually cause a reduction in insulation resistance  
and generator output may be affected.  
Winding insulation in Generac generators is moisture  
resistant. However, prolonged exposure to water,  
high humidity, salt air, etc., will gradually reduce the  
resistance of winding insulation.  
Dirt can make the problem even worse, since it tends  
to hold moisture into contact with the windings. Salt,  
as from sea air, can also worsen the problem, since  
salt tends to absorb moisture from the air. When salt  
and moisture combine, they make a good electrical  
conductor.  
Because of the detrimental effects of water, dirt and  
salt, the generator should be kept as dry and as clean  
as possible. Stator windings should be tested periodi-  
cally using a Hi-Pot tester or a Megohmmeter. If insu-  
lation resistance is low, drying of the unit may be nec-  
essary. If resistance is still low after drying, the defec-  
tive Stator should be replaced.  
STATOR LEADS  
The following leads are brought out of the Stator and  
connected to various components in the unit:  
WIRE# COLOR  
CONNECTS TO  
AC1  
AC2  
SL1  
SL2  
TIM1  
TIM2  
PS1  
PS2  
77  
Grey  
CB1A  
Yellow  
Orange  
Brown  
Orange  
Grey  
BR1  
CB1B  
BR3  
A6060 Circuit Board  
A6060 Circuit Board  
J1  
Red  
INSULATION RESISTANCE TESTERS  
Black  
Brown  
Brown  
Black  
J1  
Battery Charge Rectifier BCR  
Battery Charge Rectifier BCR  
Grounding Terminal  
One kind of insulation resistance tester is shown in  
Figure 1, below. Other types are commercially avail-  
able. The type shown has a "Breakdown" lamp which  
turns on to indicate an insulation breakdown during  
the test.  
66  
55  
One common type of tester is the "Megohmmeter"  
which measures resistance in "Megohms".  
Figure 2. Stator Leads  
PREPARATION FOR TESTS  
See Stator leads CHART above. Disconnect and iso-  
late all Stator leads. ALL STATOR LEADS MUST BE  
DISCONNECTED AND ISOLATED BEFORE START-  
ING THE TESTS.  
Figure 1. One Kind of Hi-Pot Tester  
Page 1.4-1  
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Section 1.4  
INSULATION RESISTANCE  
4. POWER PHASE TO BATTERY CHARGE WINDINGS:Connect  
one tester probe to Stator Lead AC1, the other probe to Stator  
lead No. 55. Apply 1000 volts. If breakdown Is indicated, the  
windings are shorted together. Repeat again with stator lead  
SL1.  
TEST ALL STATOR WINDINGS TO GROUND  
Connect the ends of all Stator leads together. Make  
sure none of the leads are touching any terminal or  
any part of the generator.  
Connect one Tester probe to the junction of all Stator  
leads; the other Tester probe to a clean frame ground  
on the Stator. Apply a voltage of 1000 volts for about  
1 second.  
Follow the tester manufacturer's instructions carefully.  
Some "Hi-Pot" testers are equipped with a  
"Breakdown" light which will turn ON to indicate an  
insulation breakdown.  
A "Megger" (Megohmmeter) will indicate the  
"megohms" of resistance. Normal Stator winding  
insulation resistance is on the order of "millions of  
ohms" or "megohms". The MINIMUM acceptable  
insulation resistance reading for Stators can be calcu-  
lated using the following formula.  
5. TIMING TO POWER SUPPLY WINDING:- Connect one tester  
probe to Stator lead No. TM1, the other test probe to Stator  
lead No. PS1. Apply 1000 volts. If breakdown is indicated, the  
windings are shorted together.  
6. TIMING TO BATTERY CHARGE WINDING:- Connect one test  
probe to Stator lead No. TIM1, the other test probe to Stator  
lead No. 55. Apply 1000 volts. If breakdown is indicated the  
windings are shorted together.  
7. POWER SUPPLY TO BATTERY CHARGE WINDING:Connect  
one test probe to Stator lead No. PS1, the other probe to Stator  
lead No. 55. Apply 1000 volts. If breakdown is indicated, the  
windings are shorted together.  
MINIMUM INSULATION  
GENERATOR RATED VOLTS  
=
+1  
RESISTANCE  
1000  
(in “megohms”)  
EXAMPLE: Generator rated voltage Is "120 VAC".  
Divide 120 by 1000 to obtain "0.12". Add "1" to  
obtain "1.12". Minimum Insulation resistance for  
the unit Is "1.12 megohms".  
RESULTS OF TESTS  
1. If testing indicates that Stator windings are shorted to ground,  
the Stator should be cleaned and dried. The insulation resis-  
tance tests should then be repeated. If, after cleaning and dry-  
ing, the Stator again fails the test, replace the Stator assembly.  
TEST FOR SHORTS BETWEEN WINDINGS  
2. If testing indicates that a short between windings exists,  
clean and dry the Stator. Then, repeat the tests. If Stator  
fails a second test (after cleaning and drying), replace the  
Stator assembly.  
Figure 2 on the previous page shows the Stator leads  
that are brought out of the Stator. Figure 3 is a  
schematic representation of the eight (8) Stator wind-  
ings. To test for shorts between windings, proceed as  
follows:  
1. Make sure all Stator output leads are isolated from each other  
and from the frame.  
CLEANING THE GENERATOR  
2. POWER PHASE TO TIMING WINDINGS:- Connect one tester  
probe to Stator lead AC1, the other test probe to Stator lead  
TIM1. Apply a voltage of 1000 volts. The Tester will indicate a  
breakdown if the windings are shorted together. Repeat again  
with stator lead SL1.  
GENERAL:  
If testing indicates that the insulation resistance is  
below a safe value, the winding should be cleaned.  
Proper cleaning can be accomplished only while the  
generator is disassembled. The cleaning method  
used should be determined by the type of dirt to be  
removed. Be sure to dry the unit after it has been  
cleaned. An electric motor repair shop may be able to  
assist with cleaning. Such shops are often experi-  
enced in special problems (sea coast, marine, wet-  
land applications, etc.).  
3. POWER PHASE TO POWER SUPPLY WINDINGS: Connect  
one tester probe to Stator lead AC1, the other tester probe to  
Stator lead PS1. Apply 1000 volts. If a breakdown Is indicated,  
the windings are shorted together. Repeat again with stator lead  
SL1.  
Page 1.4-2  
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Section 1.4  
INSULATION RESISTANCE  
DANGER! DO NOT WORK WITH SOLVENTS  
IN ANY ENCLOSED AREA. ALWAYS PRO-  
VIDE ADEQUATE VENTILATION. FIRE,  
EXPLOSION OR OTHER HEALTH HAZARDS  
MAY EXIST UNLESS ADEQUATE VENTILA-  
TION IS PROVIDED. WEAR EYE PROTEC-  
TION. WEAR RUBBER GLOVES TO PROTECT  
THE HANDS.  
!
!
CAUTION! Some generators use epoxy or  
polyester base winding varnishes. Use sol-  
vents that do not at tack such materials.  
DRYING THE GENERATOR  
GENERAL:  
If testing indicates that the insulation resistance of a  
winding Is below a safe value, the winding should be  
dried before operating the unit Some recommended  
drying methods include (a) heating units and (b)  
forced air.  
HEATING UNITS:  
Figure 3. Schematic - Stator Windings  
USING SOLVENTS FOR CLEANING:  
A solvent is generally required when dirt contains oil  
or grease. Only petroleum distillates should be used  
to clean electrical components. Recommended are  
safety type petroleum solvents having a flash point  
greater than 100° F. (38° C.).  
Use a soft brush or cloth to apply the solvent. Use  
care to avoid damaging magnet wire or winding insu-  
lation. After cleaning, dry all components thoroughly  
with moisture-free, low pressure compressed air.  
If drying is needed, the generator can be enclosed in  
a covering. Heating units can then be installed to  
raise the temperature about 15°-18° F. (8°-10° C.)  
above ambient.  
FORCED AIR:  
Portable forced air heaters can be used to dry the  
generator. Direct the heated air into the generator's  
air intake openings. Run the unit at no-load. Air tem-  
perature at the point of entry into the generator should  
not exceed 150° F. (66° C.).  
Page 1.4-3  
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Section 1.4  
INSULATION RESISTANCE  
Page 1.4-4  
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Section 1.5  
COMPONENTS TESTING  
1.Disconnect the following wires:  
INTRODUCTION  
a. Lead "AC1" (Grey) at CB1A.  
b. Lead "AC2" (Yellow) at BR1.  
c. Lead "SL1 " (Orange) at CB1B.  
d. Lead "SL2" (Brown) at BR3.  
Problems that occur In the computer-controlled RV  
generator generally involve the following systems or  
components:  
1. The engine.  
2.Make sure all of the disconnected leads are iso-  
lated from each other and are not touching the  
frame during the test.  
2. The Speed Control System.  
3. The AC Generator.  
3.Set a VOM to its "Rx1" scale and zero the meter.  
4. Battery Charge Circuit.  
5. A6060 Circuit Board.  
6. Wiring Harness and Front Panel.  
4.Connect one test lead to AC1 and one test lead  
to AC2. Note the resistance reading.  
5.Connect one test lead to SL1 and one test lead  
to SL2. Note the resistance reading.  
This Section will discuss test procedures for the fol-  
lowing components. Also see Part 8 of this Manual,  
"TROUBLESHOOTING".  
NOMINAL RESISTANCE- POWER PHASE WINDINGS  
0.414 to 0.465 ohm  
1. The AC Generator (Stator).  
2. Battery Charge Circuit.  
3. A6060 Circuit Board.  
STATOR ASSEMBLY  
GENERAL:  
For additional information on the Stator, refer to the  
following:  
1. "Stator Assembly" on Page 1.2-2.  
2. Section 1.4, "INSULATION RESISTANCE".  
SYMPTOMS OF STATOR FAILURE:  
If the engine starts but the Stepper Motor does not  
move, and shutdown occurs after several seconds,  
look for broken or shorted timing windings (Wires  
TIM1 and TIM2).  
Figure 1. Stator Leads  
B. To test the Power Phase windings for a "short-to-ground" con-  
dition, proceed as follows:  
TESTING THE STATOR WITH A VOM:  
A Volt-Ohm-Milliammeter (VOM) can be used to test  
the Stator windings for the following faults:  
1.Make sure all leads are Isolated from each other  
and are not touching the frame.  
• An open circuit condition.  
2.Set a VOM to its "Rx10,000" or "Rx1K" scale  
and zero the meter.  
• A "short-to-ground" condition.  
• A short circuit between windings.  
3.Connect one VOM test lead to the terminal end  
of Stator Lead "AC1”, the other test lead to a  
clean frame ground on the Stator.  
NOTE: The resistance of Stator windings Is very  
low. Some meters will not read such a low resis-  
tance and will simply Indicate "continuity"  
Recommended Is a high quality, digital type meter  
capable of reading very low resistances.  
a. The meter should read "infinity".  
b. Any reading other than "infinity" indicates a  
"short-to-ground" condition.  
TESTING POWER PHASE WINDINGS:  
c. Repeat #3 again using Stator Lead “SL1.”  
A. Refer to Figures 1 and 2 on this page and the next. To test the  
Power Phase windings for an open circuit condition, proceed  
as follows:  
Page 1.5-1  
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Section 1.5  
COMPONENTS TESTING  
TESTING THE TIMING WINDING:  
STATOR ASSEMBLY (CONTINUED)  
A. To test the Stator Timing winding for an open circuit condition,  
proceed as follows:  
1.Disconnect the 2-pin connector from "J5" of the  
A6060 circuit board. See Figure 3.  
a. Stator lead TIM1 (Orange) connects to Pin  
1 of the “J5” connector.  
b. Stator lead TIM2 (Gray) connects to Pin 2  
of the “J5” connector.  
2.Set a VOM to its "Rx1" scale and zero the  
meter.  
3.Connect one VOM test lead to Pin 1 (Lead TIM1  
Orange); connect the. other test lead to Pin 2  
(Lead TIM2- Gray). The meter should Indicate  
the Stator Timing winding resistance.  
NOMINAL RESISTANCE  
STATOR TIMING WINDING  
0.102-0.116 ohm  
B.To test the Timing winding for a "short-to-ground" condition,  
proceed as follows:  
1.Set the VOM to its "Rx10,000" or "Rx1 K" scale  
and zero the meter.  
2.Connect one VOM test lead to Pin 1 of the 2-pin  
connector (Lead TIM1-Orange).  
Figure 2. Schematic- Stator Windings  
TESTING POWER SUPPLY WINDINGS:  
3.Connect the other test lead to a clean frame  
ground on the Stator. The meter should read  
"infinity". Any reading other than "infinity" indi-  
cates the Timing winding is shorted to ground.  
A. To test the Power Supply winding for an open circuit condition,  
proceed as follows:  
1.Disconnect the 2-wire power supply from the  
generator. See Figure 3.  
SHORT CIRCUIT BETWEEN WINDINGS:  
To test for a short circuit between windings, proceed  
as follows:  
1.Set a VOM to its "Rx10,000" or "Rx1K" scale  
and zero the meter.  
2.Set a VOM to its "Rx1" scale and zero the meter.  
3.Connect one VOM test lead to Lead PS1- Red,  
the other test lead to Lead PS2 - Black. The  
meter should indicate the resistance of the  
Power Supply winding.  
2.Connect one meter test lead to Stator lead PSi  
(Red).  
NOMINAL RESISTANCE  
POWER SUPPLY WINDING  
0.206-0.227 ohm  
3.Connect the remaining test lead to Stator lead  
AC1 (Grey). The meter should read "infinity".  
Any reading other than "infinity" indicates a  
shorted condition and the Stator should be  
replaced.  
B. To test the Power Supply winding for a "short-to-ground" condi-  
tion, proceed as follows:  
4.Connect one VOM test lead to Stator lead AC1,  
the other test lead to Stator lead 77. The VOM  
should read "infinity".  
1.Set the VOM to its "Rx10,000" or "Rx1 K" scale  
and zero the meter.  
2.Connect one VOM test lead to Lead PS1 - Red.  
Connect the other test lead to a clean frame  
ground on the Stator. The meter should read  
"infinity.”  
5.Connect one VOM test lead to Stator lead AC1,  
the other test lead to Stator lead TIM1. The  
meter should read "infinity".  
6.Connect one test lead to Stator lead PSI, the  
other to Stator lead TIM1. "Infinity" should be  
indicated.  
NOTE: Any reading other than °Infinity" Indicates  
the winding Is shorted to ground. If winding is  
open or shorted, the Stator should be replaced.  
Page 1.5-2  
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Section 1.5  
COMPONENTS TESTING  
7.Connect one test lead to Stator lead PS1, the  
other to Stator lead 77. The VOM should read  
"infinity".  
8.Connect one VOM test lead to Stator lead TIM1,  
the other test lead to Stator lead 77. "Infinity"  
should be Indicated.  
TESTING THE BATTERY CHARGE CIRCUIT  
GENERAL:  
The Stator is equipped with dual battery charge wind-  
ings. These windings deliver an AC output to a  
Battery Charge Rectifier (BCR) which rectifies it  
(changes it to direct current or DC). The direct current  
is delivered to the unit battery, to maintain the battery  
in a charged state while the unit is running.  
Figure 4. Battery Charge Circuit  
TESTING THE BATTERY CHARGE CIRCUIT:  
Test the Battery Charge winding as follows:  
1. Disconnect Wire 77 at the Battery Charge Rectifier (BCR).  
2. Disconnect Stator output Wire 66 at the Battery Charge  
Rectifier (BCR).  
3. Disconnect Wire 55.  
4. Set a VOM to its "Rx1 " scale and zero the meter.  
5. Connect the VOM test leads across Wires 77 and 55, then  
across Wires 66 and 55. Note the resistance reading in both  
cases. Replace Stator Assembly, if defective.  
BATTERY CHARGE WINDING RESISTANCE  
ACROSS WIRES 66 TO 55 = 0.095-0.108 Ohm  
ACROSS WIRES 77 TO 55 = 0.095-0.108 Ohm  
Figure 3. Battery Charge Windings and Rectifier  
SYMPTOMS OF CIRCUIT FAILURE:  
It is difficult to determine if the battery charge circuit is  
operating without testing for correct voltage. If you  
suspect the battery charge circuit Is defective, the fol-  
lowing symptoms will usually point to a cause of the  
problem. See Figure 4.  
6. Use a VOM to measure AC voltage at the Wires 66 and 77 ter-  
minals of the Battery Charge Rectifier, with the unit running. If  
no AC voltage is measured, an open circuit exists in the wire  
66 or 77 circuit.  
7. With engine running, use a VOM to check for DC voltage  
between the Battery Charge Rectifiers Wire 55 and frame  
ground. If AC voltage was present in step 6, but DC voltage is  
NOT present in this step, the Battery Charge Rectifier (BCR) is  
defective.  
1. If no AC voltage can be measured across Stator connections at  
the Battery Charge Rectifier (BCR), an open circuit condition  
probably exists in Wire 66 (Brown), or Wire 77 (Brown).  
2. If AC voltage (s available to the Wire 66 and 77 terminals at the  
battery Charge Rectifier, but no voltage or a low voltage is mea-  
sured between the BCR's Wire 55 terminal and ground, the  
Battery Charge Rectifier (BCR) is defective.  
Page 1.5-3  
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Section 1.5  
COMPONENTS TESTING  
Page 1.5-4  
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Section 1.6  
CONTROL PANEL  
CONSTRUCTION  
COMPONENTS  
The panel is constructed of sheet metal and includes  
a panel box, a panel back cover and a front control  
panel. The panel box is retained to an engine-genera-  
tor divider plate by five M5 screws. Removal of these  
screws will permit the panel to be removed from the  
divider plate and set out of the way with connecting  
wires still attached. This will allow access to compo-  
nents housed in the control panel.  
A heat sink bracket is attached to the engine-genera-  
tor divider plate, for attachment of a heat sink to  
which four diode assemblies are mounted. See Items  
26 and 31 in the Exploded View of Control Panel.  
Other components are also shown in the Exploded  
View. Many of these components are part of the  
"ENGINE ELECTRICAL SYSTEM" (Part 6 of this  
manual).  
52  
28  
18  
38  
51  
38  
31  
26  
58  
48  
31  
37  
19  
27  
5
13  
64  
51  
1
6
32  
13  
19  
36  
35  
69  
43  
44  
28  
14  
26  
33  
2
7
47  
28  
34  
4
3
62  
61  
10  
20  
16  
25  
41  
14  
34  
33  
53  
6
20  
45  
57  
60  
10  
46  
25  
24  
22  
23  
21  
63  
13  
25  
50  
59  
1
30  
**ITEMS #49, 65 & 66-HARNESSES- NOT SHOWN FOR CLARITY  
ITEM  
1
QTY.  
7
DESCRIPTION  
ITEM  
36  
37  
38  
41  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
69  
QTY.  
2
DESCRIPTION  
BUS BAR, OUTER  
TAPTITE M6- 1.0 x 10MM  
BRACKET, HEAT SINK-PCB  
TERMINAL BLOCK  
BUS BAR, INNER  
GROUND WIRE  
DC POWER HARNESS  
REMOTE PANEL HARNESS  
SNAP BUSHING  
M5-0.8 x 12MM PHILLIPS PAN HD. MACH. SCR.  
BOX, CONTROL TOP  
BOX, CONTROL PANEL  
#10-32 x 1" PHILLIPS PAN HD. MACH. SCR.  
#10-32 HEX NUT  
2
1
4
3
1
1
4
1
1
5
1
4
6
8
TAPTITE M5- .8 x 10MM  
SNAP BUSHING  
1
7
1
1
10  
13  
14  
16  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
30  
31  
32  
33  
34  
35  
1
CIRCUIT BREAKER,15A.  
LOCK WASHER-M5  
1
6
1
10  
2
M4-0.7 x 16MM  
1
CLAMP, CONTROL PANEL HARNESS  
HARNESS, CONTROL PANEL  
#6-32 x 1/4" PHILLIPS ROUND HD. MACH. SCREW  
RUBBER U-CHANNEL 3.5 FT  
M4-0.7 x 10MM HEX HEAD CAPSCREW  
HOUR METER  
M4-0.7 HEX NUT  
1
4
M4 FLAT WASHER  
4
8
M5 FLAT WASHER  
1
1
CONTROL PANEL, FRONT  
RUBBER GROMMET  
SWITCH, SPDT ROCKER  
SWITCH, SPSTMOM ROCKER  
FUSE, 7.5A. AGC  
4
1
1
1
4
PPHMS 10-32 x 3/8" LG  
1
1
BUS BAR, CENTER  
1
1
BLACK TIE WRAP, 7" LG  
1
FUSE HOLDER  
4
SHAKEPROOF EXT. #10  
1
EXTRUSION, CONTROLLER  
RECTIFIER, BATTERY CHARGE  
LOCK WASHER-M4  
1
INVERTER ASSEMBLY  
1
1
WIRE HARNESS  
14  
1
2
M6 FLAT WASHER  
PANEL DECAL  
DIODE, DUAL 30A  
1
WIRE HARNESS-HEATSINK TO PCBI  
HARNESS-PCBI TO PANEL  
HARNESS-HEATSINK TO TERM. BLOCK  
M3-0.5 NUT  
4
1
1
ASSEMBLY, PCB CCG  
PHMS M3-.05 x 10MM  
LOCK WASHER-M3  
1
4
2
4
1
RESISTOR, POWER 1 OHM  
Figure 1. Exploded View of Control Panel  
Page 1.6-1  
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Section 1.6  
CONTROL PANEL  
Page 1.6-2  
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Section 1.7  
SHEET METAL  
GENERAL  
See "Exploded View of Sheet Metal" on next page. A  
DIVIDER PLATE (Item 1) separates the AC generator  
components from the engine. The engine Itself is  
enclosed by a BASE HOUSING WRAPPER (Item 4),  
a FRAME (Item 24), and a BELLY PAN (Item 23).  
These components are sealed by means of rubber  
SEALS (Items 3), to prevent  
The LOWER FAN attaches to the engine shaft and is  
enclosed in a LOWER FAN HOUSING (Item 19). Air  
is drawn Into the enclosed area around the engine  
and forced out of the LOWER FAN HOUSING.  
Removal of sheet metal will be necessary for many  
repairs and for replacement of most parts.  
Impact Plus Generator  
Page 1.7-1  
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Section 1.7  
SHEET METAL  
EXPLODED VIEW OF SHEET METAL (GASOLINE UNITS)  
1
2
59  
39  
30  
44  
22  
4
38  
3
5
57  
3
4
78  
69  
9
3
59  
57  
5
20  
69  
21  
24  
22  
59  
25  
39  
3
3
69  
34  
33  
59  
32  
45  
53  
44  
65  
30  
29  
67  
68  
64  
7
53  
35  
29  
40  
41  
30  
7
6
TO CARBURETOR  
60  
8
23  
5
50  
62  
31  
5
37  
5
26  
37  
47  
61  
81  
5
71  
63  
64  
28  
27  
7
75  
77  
78  
30  
79  
48  
49  
5
19  
12  
13  
39  
73  
72  
42  
54  
74  
59  
18  
70  
51  
36  
37  
76  
80  
5
17  
Page 1.7-2  
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Section 1.7  
SHEET METAL  
PARTS LIST FOR SHEET METAL (GASOLINE UNITS)  
ITEM QTY  
DESCRIPTION  
ITEM QTY  
DESCRIPTION  
1
2
3
4
5
6
7
8
1
2
1
1
31  
2
12  
4
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
7
1
1
1
1
4
1
5
1
4
2
2
PLATE, DIVIDER  
M6-1.0 HEX NUT  
SEAL RUBBER EXTRUSION 3.5 FT  
WRAPPER, BOX  
TAPTITE, M5- .8 x 10MM LONG  
MOUNTING RAILS  
M8 LOCK WASHER  
M8-1.25 x 35MM HEX HD. CAPSCR.  
HHCS M5-0.8 x 40MM  
SPARK ARRESTOR  
U-BOLT, W/SADDLE & NUTS  
DEFLECTOR, AIR OUT  
ASSEMBLY, MUFFLER  
HOUSING, LOWER FAN  
SKIRT, CARB. BAFFLE  
COVER, ROCKER COVER  
SKIRT, SPARK PLUG SIDE  
PAN, BELLY  
FRAME  
GROUND STRAP  
PLATE, BASE COVER  
PUMP, FUEL  
BARBED 90 1/8" x 1/4"  
HEX NUT 1/4"-20  
LOCK WASHER-1/4"-M6  
CONTACTOR, STARTER  
BOOT, CONTACTOR  
SEAL, OIL FILTER HOLE  
RETAINER, SEAL  
M8 FLAT WASHER  
1/4" FUEL LINE-4" LONG  
1/4" HOSE CLAMP  
42  
2
HEX HD. CAPSCR. M6-1.0 x 16MM-  
W/LOCKWASHER  
44  
45  
47  
3
1
1
SPECIAL LOCK WASHER, M6  
GROUND STRAP, UNIT  
1/8" x 3/16" NPT 90 DEG.  
BARBED FITTING  
BRACKET, MUFFLER HANGER  
1/4" FUEL LINE (8" LONG)  
3/16" CARBURETOR LINE (4" LONG)  
FUEL FILTER  
48  
49  
50  
51  
53  
1
1
1
1
1
9
12  
13  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
STARTER CONTACTOR GROUND  
WIRE  
54  
57  
59  
60  
61  
62  
63  
64  
65  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
81  
1
1
13  
1
2
4
2
8
3
2
2
6
1
2
1
1
2
4
2
2
4
1
1
1
SEAL, WASHER EXHAUST PIPE  
PANEL, WRAPPER BOX  
CRIMPTITE #10-24 x 1/2"  
HEX HD. CAPSCR., M5-0.8 x 12 G8.8  
CUSTOMER MOUNTING BRACKET  
VIBRATION MOUNT  
EARTHING STRAP  
HEX NUT M8  
VIBRATION MOUNT  
TAPTITE 1/4"-20 x 1-1/4"  
TAG, REMOVE BOLT  
FLAT WASHER #10-M5  
BRACKET, IGNITION SYSTEM  
SPACER, IGNITION COIL  
MODULE, IGNITION  
ASSEMBLY, IGNITION COIL  
M6-1.0 x 35MM HEX HD. CAPSCREW  
M6-1.0 HEX NUT  
M5-0.8 x 12MM-PPHMS  
M5-0.8 HEX NUT  
LOCK WASHER M5  
SNAP BUSHING  
SPECIAL LOCK WASHER, M5  
#8 HEX NUT  
RUBBER "U" CHANNEL 0.5 FT  
CRIMPTITE #10-24 x 3/8"  
COVER, IGNITION SYSTEM  
#8 LOCK WASHER  
Page 1.7-3  
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Section 1.7  
SHEET METAL  
EXPLODED VIEW OF SHEET METAL (LP UNITS)  
1
75  
30  
44  
22  
4
38  
3
11  
3
4
3
2
11  
5
20  
43  
21  
24  
22  
2
25  
39  
3
3
43  
34  
33  
27  
2
37  
47  
45  
53  
44  
65  
30  
29  
59  
30  
67  
68  
64  
7
36  
81  
51  
58  
49  
35  
57  
51  
7
6
8
23  
9
62  
43  
78  
5
50  
32  
51  
60  
55  
61  
63  
64  
53  
7
29  
40  
41  
30  
48  
5
5
19  
12  
51  
5
31  
26  
66  
5
42  
71  
75  
77  
78  
2
18  
30  
79  
39  
73  
74  
72  
80  
54  
5
17  
70  
76  
Page 1.7-4  
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Section 1.7  
SHEET METAL  
PARTS LIST FOR SHEET METAL (GASOLINE UNITS)  
ITEM QTY  
DESCRIPTION  
ITEM QTY  
DESCRIPTION  
1
2
3
4
5
6
7
8
1
32  
3.5'  
1
31  
2
12  
4
3
1
1
1
1
1
1
1
1
1
1
1
1
1
5
9
1
1
1
1
4
1
1
1
2
2
2
2
PLATE, DIVIDER  
44  
45  
47  
48  
49  
50  
51  
53  
3
1
1
1
2
1
2
1
SPECIAL LOCK WASHER, M6  
GROUND STRAP, UNIT  
HOSE-3/8" I.D. x 11-1/2" LONG  
BRACKET, MUFFLER HANGER  
STREET ELBOW 45 DEG. 3/4" NPT  
PIPE NIPPLE 3/4" x 2"  
U BOLT W / SADDLE & 2-NUTS  
STARTER CONTACTOR GROUND  
WIRE  
SEAL, WASHER EXHAUST PIPE  
FUEL SOLENOID 12V DC  
5/16" FLAT WASHER  
BRACKET L/P  
CAPSCR., HEX HD.-1/4"-20 x 1/2"  
LP HOOK-UP FITTING  
CUSTOMER MOUNTING BRACKET  
VIBRATION MOUNT  
EARTHING STRAP  
HEX NUT-M8  
VIBRATION MOUNT  
COVER, IGNITION BRACKET  
1/4"-20 TAPTITE 1-1/4"  
TAG, BOLT REMOVAL  
BRACKET, IGNITION SYSTEM  
SPACER, IGNITION COIL  
MODULE, IGNITION  
ASSEMBLY, IGNITION COIL  
M6-1.0 x 35MM HEX HD. CAPSCREW  
M6-1.0 HEX NUT  
CRIMPTITE 10-24 x 1/2"  
SEAL, RUBBER EXTRUSION  
BOX, WRAPPER  
TAPTITE, M5-.8 x 10MM  
MOUNTING RAILS  
M8 LOCK WASHER  
M8-1.25 x 35MM HEX HD. CAPSCR.  
HHCS M5-0.8 x 40MM  
WRAPPER, END PANEL  
SPARK ARRESTER  
DEFLECTOR, AIR OUT  
ASSEMBLY, MUFFLER  
HOUSING, LOWER FAN  
SKIRT, CARB. BAFFLE  
COVER, ROCKER COVER  
SKIRT, SPARK PLUG SIDE  
PAN, BELLY  
9
11  
12  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
54  
55  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
67  
68  
70  
71  
72  
73  
74  
75  
76  
1
1
2
1
2
1
2
4
2
8
3
1
1
1
1
2
1
1
2
4
2
FRAME  
GROUND STRAP  
PLATE, BASE COVER  
BARBED EL 90 3/8NPT X 3/8 VS  
HEX NUT, 1/4"-20  
LOCK WASHER-1/4"-M6  
CONTACTOR, STARTER  
BOOT, CONTACTOR  
SEAL, OIL FILTER HOLE  
RETAINER, SEAL  
FLAT WASHER-M8  
REGULATOR  
HOSE CLAMP #5.5  
SNAP BUSHING  
SPECIAL LOCK WASHER, M5  
#8-32 HEX NUT  
#8 LOCK WASHER  
HEX HD. CAPS., M6-1.0 x 16MM-W/L-  
WASHER  
M5-0.8 x 12MM PHILLIPS PAN HD.  
MACH. SCR.  
M5-0.8 HEX NUT  
77  
78  
79  
80  
81  
2
5
.5  
1
LOCK WASHER, M5  
RUBBER "U" CHANNEL  
CRIMPTITE #10-24 x 3/8"  
WIRE ASSEMBLY, BLOCKING DIODE  
1
43  
7
FLAT WASHER #10/M5  
Page 1.7-5  
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Section 1.7  
SHEET METAL  
Page 1.7-6  
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PART 2  
ENGINE  
SECTION  
2.1  
TITLE  
GENERAL INFORMATION  
MECHANICAL  
2.2  
2.3  
2.4  
VALVE TRAIN  
PISTON, RINGS, CONNECTING ROD  
CRANKSHAFT & CAMSHAFT  
COMPUTER  
CONTROLLED  
VARIABLE  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Section 2.1  
GENERAL INFORMATION  
INTRODUCTION  
The engine used on Impact 36 plus Series recreational  
vehicle AC generators is a Generac Series GV-220,  
vertical shaft, single cylinder, overhead valve type.  
These engines are not equipped with a mechanical  
engine governor. Instead. variable engine speeds are  
controlled by a computer circuit board. The circuit  
board signals a stepper motor to move the carburetor  
throttle linkage.  
4-CYCLE ENGINE THEORY  
Figure 1. Intake Stroke  
Figure 2. Compression Stroke  
Figure 3. Power Stroke  
GENERAL:  
Series GV-220 engines require four (4) strokes or  
cycles to complete one power cycle. This is often  
called the "4-stroke, 5-event" cycle. The 4 strokes and  
5 events that occur are (1) Intake, (2) compression,  
(3) Ignition, (4) power and (5) exhaust  
INTAKE STROKE (FIGURE 1):  
The intake valve is open. The exhaust valve is closed.  
The piston travels downward, creating a suction  
which draws the air-fuel mixture from the carburetor  
into the cylinder and just above the piston.  
COMPRESSION STROKE (FIGURE 2):  
As the piston reaches bottom dead center (BDC), the  
intake valve closes. The exhaust valve remains  
closed, as well. The piston starts to move outward in  
the cylinder. Since both valves are closed, the air-fuel  
mixture in the cylinder is compressed.  
POWER STROKE (FIGURE 3):  
Both valves remain closed. At some point before the  
piston reached top dead center (TDC), the spark plug  
fires to Ignite the fuel-air mixture. The piston moves to  
its top dead center position and the burning, expand-  
ing gases of combustion force the piston downward.  
EXHAUST STROKE (FIGURE 4):  
The expanding gases of combustion force the piston  
downward to its bottom dead center (BDC) position.  
The exhaust valve then opens, as the piston starts its  
movement toward top dead center (TDC). Piston  
movement then forces the exhaust gases out through  
the open exhaust valve. The 4-stroke cycle of events  
then starts over again.  
Figure 4. Exhaust Stroke  
Page 2.1-1  
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Section 2.1  
GENERAL INFORMATION  
TIMING:  
GASEOUS FUEL SYSTEMS:  
Valve timing and ignition timing must be precisely  
controlled if the engine is to operate properly and effi-  
ciently. Intake and exhaust valves must open and  
close in a precise timed sequence if the four strokes  
are to occur. Ignition must occur at exactly the correct  
piston position, just prior to the start of the power  
stroke. Timing of valve opening and closing, as well  
as of spark occurrence, is given in relation to the pis-  
ton position and the degrees of crankshaft rotation.  
Ignition Is timed to occur several degrees before top  
dead center (TDC) of the piston, to allow time for the  
air-fuel mixture to ignite and start to bum before the  
piston reaches top dead center  
Some RV generator models may be equipped with an  
LP or natural gas fuel system. The use of such  
gaseous fuels may result in a slight power loss as  
compared to gasoline. However, that disadvantage is  
usually compensated for by the many advantages  
offered by such fuels. Some of these advantages are:  
A low residue content which results in minimum  
carbon formation in the engine.  
Reduced sludge buildup in the engine oil.  
Reduced burning of valves as compared to gaso-  
line. No "washdown" of the engine cylinder wall dur-  
ing cranking and startup.  
Excellent anti-knock qualities.  
A nearly homogenous mixture in the engine cylinder.  
There must be no leakage past the valves in their  
closed position or compression will not develop.  
Likewise, there must be no leakage past the piston  
Fuel can be stared for long periods without break-  
down.  
RECOMMENDED FUELS  
DANGER! GASEOUS FUELS ARE HIGHLY  
VOLATILE AND THEIR VAPORS ARE EXPLO-  
SIVE. LP GAS IS HEAVIER THAN AIR AND  
!
GASOLINE FUEL SYSTEMS:  
WILL SETTLE IN LOW AREAS. NATURAL  
GAS IS LIGHTER THAN AIR AND WILL ACCU-  
MULATE IN HIGH AREAS. EVEN THE SLIGHT-  
EST SPARK CAN IGNITE THESE FUELS AND  
CAUSE AN EXPLOSION. THE USE OF LEAK  
DETECTORS IS RECOMMENDED WHEN  
GASEOUS FUELS ARE USED. ALL CODES,  
STANDARDS AND REGULATIONS PERTAIN-  
ING TO THE INSTALLATION AND USE OF  
GASEOUS FUELS MUST BE COMPLIED  
WITH.  
For models equipped with a gasoline fuel system, the  
use of clean, fresh, UNLEADED, regular grade gaso-  
line is recommended. Unleaded gasoline burns clean-  
er, extends engine life, and promotes better starting by  
reducing carbon deposits in the combustion chamber.  
Leaded "Regular" grade gasoline may be used if  
unleaded gasoline is not available.  
The use of gasohol is NOT recommended. If it must  
be used, it should not contain more than 10 percent  
ethanol. When gasoline containing ethanol is used,  
special care is required when preparing the unit for  
storage (see "Storage Instructions"  
NOTE: DO NOT USE GASOLINE CONTAINING  
METHANOL.  
RECOMMENDED ENGINE OIL  
NOTE: DO NOT MIX OIL WITH THE GASOLINE.  
Use a clean, high quality, detergent oil that is classi-  
fied "For Service SC, SD, SE, SF or SG". Use no  
special additives with the oil.  
During summer months (above 32° F. or 0° C.), use  
SAE 30 oil. SAE 10W-30 oil is an acceptable sub-  
stitute.  
During winter months (below 32° F. or 0° C.), use  
SAE 5W-20 or 5W-30 oil.  
DO NOT USE SAE 10W-40 OIL.  
DANGER! GASOLINE IS EXTREMELY FLAM-  
MABLE AND ITS VAPORS ARE EXPLOSIVE.  
DO NOT PERMIT SMOKING, OPEN FLAME,  
SPARKS OR ANY SOURCE OF HEAT !N THE  
VICINITY WHILE HANDLING GASOLINE.  
AVOID SPILLAGE OF GASOLINE ON A HOT  
ENGINE. THERE MUST BE NO LEAKAGE OF  
GASOLINE INTO THE RV GENERATOR COM-  
PARTMENT.  
!
Page 2.1-2  
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Section 2.1  
GENERAL INFORMATION  
Engine crankcase oil capacity without oil filter change  
is about 29 fluid ounces (850m.  
Engine crankcase oil capacity (with oil filter change) is  
about 1 U.S. quart (946m1).  
2. Check the battery. Fill all battery cells to the proper level with  
distilled water. DO NOT USE TAP WATER IN THE BATTERY.  
If necessary, recharge the battery to a 100 percent state of  
charge or replace it, if defective.  
Change engine oil and the oil filter after the first eight  
(8) hours of operation. Thereafter, change engine oil  
and oil filter every 50 operating hours.  
3. Turn OFF all electrical loads. Start the engine at no load and  
let it warm up.  
NOTE: Additional Information on the engine oil  
system can be found in Part 5 of this manual,  
"Engine Oil and Cooling System".  
4. Apply electrical loads to at least 50% of the unit's rated  
capacity.  
5. When engine is thoroughly warmed up, turn off or disconnect  
all electrical loads. Then, shut the engine down.  
STORAGE INSTRUCTIONS  
THE UNIT IS NOW READY FOR SERVICE.  
PREPARATION FOR STORAGE:  
The engine should be started at least once every  
seven (7) days and allowed to run for at least thirty  
(30) minutes. If this cannot be done and the engine is  
to remain unused longer than thirty (30) days, it must  
be prepared for storage. To prepare the unit for stor-  
age, proceed as follows:  
ENGINE TUNE-UP  
The following procedure may be used as a minor  
tune-up. On completion of the procedure, the engine  
should run properly. If it does not run properly, addi-  
tional checks and repairs are required.  
1. Start the engine and let it warm up.  
1. Service and repair engine air cleaners, as necessary.  
2. After engine is thoroughly warmed up, shut it down.  
2. Check engine oil level and condition of oil. Add or change oil as  
required.  
NOTE: If the unit is equipped with a gasoline fuel  
system and GASOHOL was used as a fuel, turn  
off the supply of fuel to the engine and let It run  
out of gas.  
3. Remove shrouding and clean away dirt from the engine cylin-  
der head and cooling fins.  
3. While engine is still warm from running, completely drain the  
oil. Then, refill with the recommended oil. See "Recommended  
Engine Oil".  
4. Check fuel filters and clean or replace as necessary.  
5. Replace the spark plug with a Champion RC12YC (or equiva-  
lent) plug.  
4. Attach a tag to the engine indicating the viscosity and classifi-  
cation of the oil in the crankcase.  
a.Set spark plug gap to 0.030 inch (0.76mm).  
b.Install new plug and tighten to 13 foot-pounds  
(1.8 N-m).  
5. Remove the spark plug and pour about one (1) ounce (15m1)  
of clean, fresh engine oil into the spark plug threaded opening.  
Crank the engine several times to distribute the oil, then install  
and tighten the spark plug.  
c. If a torque wrench is not available, tighten spark  
plug as tight as possible with fingers and then  
(1) If plug Is RE-USED, tighten about 1/4 turn  
more with a wrench.  
6. Remove the battery and store it in a cool, dry room on a wood-  
en board. Never store the battery on any concrete or wood  
floor.  
(2) If plug is NEW, tighten it about 1/2 turn  
more with a wrench.  
6. Check that wiring is free of breaks, abrasions and are properly  
routed.  
7. Clean and wipe the generator exterior surfaces.  
7. Check for spark as outlined in "Ignition" section of Part 6 of this  
manual.  
RETURN TO SERVICE AFTER STORAGE:  
To return the unit to service after storage, proceed as  
follows:  
8. Run engine, adjust carburetor if necessary and check opera-  
tion.  
1. Verify that the correct oil is in the engine crankcase by check-  
ing the tag on the engine (see "Recommended Engine Oil".) If  
necessary, drain oil and refill with the recommended oil.  
Page 2.1-3  
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Section 2.1  
GENERAL INFORMATION  
EXPLODED VIEW OF ENGINE LONG BLOCK  
ITEM QTY  
ITEM QTY  
1
DESCRIPTION  
Connecting Rod  
DESCRIPTION  
valve Spring  
1
1
1
2
1
1
2
1
1
1
1
2
1
4
4
3
1
1
1
1
1
1
1
4
1
6
1
2
31  
32  
33  
34  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
2
1
1
2
1
1
1
2
2
1
1
2
2
2
1
5
1
2
2
1
1
2
1
1
2
2
1
1
1
2
3
4
5
6
7
8
Piston Pin  
Piston Ring Set (STD)  
1/4" Pipe Plug  
Breather Cover  
Piston  
Piston Pin Retainer  
Crankshaft & Gear Assembly  
Oil Breather Separator  
Crankcase Assembly  
Sleeve Bearing  
Crankshaft Oil Seal  
Breather Baffle Cup  
M6 Screw  
Dowel Pin  
Inner Oil Pump Rotor  
Connecting Rod Bolt  
Cylinder Head (see NOTE 1)  
Exhaust Valve  
Intake Valve  
Push Rod  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
Tappet  
Oil Pickup Screen  
Rocker Cover Gasket  
Pivot Ball Stud  
Rocker Arm  
Rocker Arm Nut  
Push Rod Guide Plate  
Head Bolt  
Rocker Cover  
Breather Gasket  
Bolt  
Outer Oil Pump Rotor  
Oil Sump Assembly  
Valve Spring Wear Washer  
Intake Valve Seal  
Oil Temperature Switch  
M3 Screw  
M3 Lockwasher  
Spark Plug (see NOTE 2)  
Oil Filter Adapter Gasket  
1/4" NPT Pipe Plug  
Lockwasher  
Dowel Sleeve  
Camshaft Assembly  
Crank Case Flange Gasket  
Cylinder Head Gasket  
Oil Pressure Spring Retainer  
Oil Pressure Spring  
Oil Pressure Relief Valve Ball  
Thread Forming Bolt  
M6 Screw & Lockwasher  
Oil Filter Adapter  
M8-1.25 Capscrew  
Oil Pressure Switch  
Valve Spring Retainer  
NOTE 2:- Use a Champion RC12YC (or equivalent)  
spark plug with gap set to 0.030 inch (0.76mm).  
NOTE 1:- Item 36 Includes valve seats and  
guides.  
Page 2.1-4  
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Section 2.2  
VALVE TRAIN  
VALVE TRAIN COMPONENTS  
Valve train components are listed below and shown in  
Figure 1, below.  
ITEM  
1
2
QTY  
2
2
DESCRIPTION  
Tappet  
Push Rod  
3
4
5
6
2
2
2
1
Rocker Arm  
Pivot Ball Stud  
Rocker Arm Jam Nut  
Push Rod Guide Plate  
Valve Spring  
7
2
8
9
10  
11  
2
2
1
1
Valve Spring Retainer  
Valve Spring Washer  
Exhaust Valve  
Intake Valve  
Figure 2. Removal of Rocker Arm over  
2. Loosen the rocker arm jam nuts on the pivot ball studs. Then,  
loosen the pivot ball studs. Remove the two pivot ball studs,  
the rocker arms and the jam nuts. Also remove the push rod  
guide plate.  
NOTE: Keep the Intake valve and exhaust valve  
parts separated. Intake and exhaust parts are  
Identical. However, once a wear pattern has been  
established on these parts their fit will be different.  
Figure 1. Valve Train Components  
Figure 3. Rocker Arm, Push Rod & Guide Plate  
VALVE COMPONENTS REMOVAL  
3. Remove the push rods. 4. Remove the cylinder head bolts,  
then remove the cylinder head and head gasket.  
1. The ROCKER ARM COVER is retained by four M6-1.00 x  
12mm screws and lockwashers. Remove the four screws and  
lockwashers, then remove the ROCKER ARM COVER and its  
gasket.  
NOTE: Replace the head gasket every time the  
head is removed. The new head gasket must be  
free of nicks and scratches as these could cause  
leakage.  
NOTE: Replace the ROCKER ARM COVER GAS-  
KET each time the COVER is removed, to ensure  
proper sealing.  
Page 2.2-1  
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Section 2.2  
VALVE TRAIN  
VALVES:  
Replace valves If they are damaged, distorted or if  
the margin is ground to less than 0.039 inch (1.0mm).  
If the valves are in useable condition, use a valve  
grinder to grind the faces to a 45' angle. Check valve  
stem diameter.  
After the valves have been reconditioned, they should  
be lapped with a suitable lapping tool and valve lap-  
ping compound.  
VALVE SERVICE  
NOTE: Proper lapping of valves and valve seats  
will remove grinding marks and ensure a good  
seal between the valve and its seat. Be sure to  
clean lapping compound from the valve seats and  
faces.  
Figure 4. Cylinder Head Removal  
VALVE MARGIN (GV-220)  
DESIGN MARGIN: 0.034-0.04 inch (0.87-1.13mm)  
WEAR LIMIT: 0.020 inch (0.50mm) Maximum  
DANGER! ALWAYS WEAR SAFETY GLASSES  
WHEN REMOVING THE VALVE SPRINGS.  
!
INTAKE VALVE STEM DIAMETER (GV-220)  
DESIGN DIAMETER: 0.274-0.275 inch (6.965-0.980mm)  
WEAR LIMIT: 0.273 Inch (6.934mm) Minimum  
5. See Figure 5, next page. Hold the valve with your fingers while  
compressing the spring with your thumb, then proceed as fol-  
lows:  
EXHAUST VALVE STEM DIAMETER (GV-220)  
DESIGN DIAMETER: 0.273-0.274 inch (6.945-6.960mm)  
WEAR LIMIT: 0.272 inch (6.909mm) Minimum  
a.While the spring is compressed, slide the larger  
hole of the valve spring retainer toward the  
valve stem.  
NOTE: Design sizes and wear limits of valve train  
components can also be found in Part 9 of this  
Manual ("SPECIFICATIONS & CHARTS").  
b.With the larger spring retainer hole around the  
valve stem, release the spring.  
VALVE SEATS:  
c. Remove the valve spring retainer, the spring  
and the spring washer.  
Valve seats are NOT replaceable. If burned or pitted,  
seats can be reground. Grind seats at a 45' angle and  
to a width of 0.039 inch (1.Mm).  
Figure 7. Valve Seat  
VALVE SEAT WIDTH GV-220)  
DESIGN WIDTH: 0.034-0.044 inch (0.87-1.13mm)  
WEAR LIMIT: 0.064 inch (1.63mm) Maximum  
VALVE GUIDES:  
Valve guides are permanently installed in the cylinder  
head and cannot be replaced. If the guides become  
worn beyond the wear limit, they can be reamed to  
accommodate a 0.020 inch (0.50mm) oversize valve  
stem. Use a straight shank hand reamer or a low  
speed drill press to ream valve guides.  
VALVE GUIDES (GV-220)  
DESIGN DIAMETER: 0.237-0.2364 inch (6.02-6.005mm)  
WEAR LIMIT: 0.238 inch (6.045mm) Maximum  
Figure 5. Removal of Valve Spring  
6. Remove the intake and exhaust valves.  
7. Clean all parts. Remove carbon from valve heads and stems.  
8. Inspect the valves and valve seats. Service parts as outlined  
under "Valve Service".  
Page 2.2-2  
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Section 2.2  
VALVE TRAIN  
NOTE: After the valve guides have been over-  
sized, be sure to recut the valve seats so they will  
align with the guides.  
Figure 10. Valve Spring  
VALVE SPRING FREE LENGTH  
GV-220: 2.0741inch (52.69mm)  
Figure 8. Valve Guides  
VALVE TAPPETS:  
FORCE REQUIRED TO COMPRESS SPRING TO 1.39  
INCH (35.2MM)  
GV-220:19.8-21.81lbs (9.0-9.9kg)  
Valve tappets can be removed during removal of the  
engine camshaft. Intake and exhaust valve tappets  
are identical. However, once a wear pattern has been  
established the two tappets should not be  
Interchanged.  
VALVE COMPONENTS INSTALLATION  
After the valve train parts have been inspected and (if  
necessary) serviced, install them as follows:  
1. Lubricate the valve stems and the valve guides with engine oil.  
2. Install the intake and exhaust valves through their respective  
valve guides In the cylinder head.  
a.The exhaust valve has the smaller head with a  
diameter of 1.053 inches (26.75mm).  
b.The intake valve has the larger head, having a  
diameter of 1.171 inches (29.75mm).  
c. Valve seat sizes in the cylinder head will match  
their respective head sizes.  
NOTE: The exhaust valve stem Is also smaller  
than that of the Intake valve.  
Figure 10. Valve Tappet  
VALVE SPRINGS:  
Inspect the valve springs. Measure the spring free  
length. Also, check the amount of force required to  
compress the spring to a length of 1.39 inch (35.2  
mm). Replace any damaged or defective spring.  
Figure 11. Installation of Intake and Exhaust Valves  
Page 2.2-3  
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Section 2.2  
VALVE TRAIN  
6. Place the push rod guide plate into position on the head. Then,  
install the rocker arm and the pivot ball stud. The rocker arm  
jam nut must be on far enough to hold the guide plate In posi-  
tion.  
VALVE COMPONENTS INSTALLATION  
(CONTINUED)  
3. Install the valve spring washers, valve springs and valve spring  
retainers over the valve guides.  
NOTE: Do NOT adjust valve clearance at this time.  
This will be done later.  
a.Hold the valve with your fingers and use your  
thumbs to compress the spring.  
b.When the spring is compressed sufficiently,  
slide the spring retainer small opening over the  
valve stem.  
c. With the smaller retainer opening around the  
valve stem, release the spring.  
Figure 14. Install Rocker Arm & Pivot Ball stud  
7. install the push rod with either end against the tappet.  
a.Place the push rod between the guide plate  
tabs.  
b.Place the rocker arm socket onto end of push  
rod.  
c. Alignment is correct when push rod ball rests In  
the rocker arm socket.  
Figure 12. Installing Valve Spring Washers  
NOTE: The pivot ball stud will be tightened when  
the valve clearance Is adjusted. After valve clear-  
ance has been adjusted, the rocker arm cover will  
be Installed.  
4. After both valves have been retained in the cylinder head, posi-  
tion a new head gasket and install the cylinder head.  
NOTE: The head gasket is coated with a special  
substance for beer sealing. The gasket must be  
free of nicks, scratches and other defects for bet-  
ter sealing.  
5. Install cylinder head bolts. Tighten the head bolts in the  
sequence shown to the recommended tightness.  
TIGHTENING TORQUE  
CYLINDER HEAD  
GV-220: 29 foot-pounds  
Figure 15. Push Rod Installation  
ADJUSTING VALVE CLEARANCE  
When adjusting valve clearance, the engine should  
be at room temperature and the piston should be at  
top dead center (TDC) of Its compression stroke  
(both valves closed).  
Figure 13. Head Bolts Tightening Sequence  
Page 2.2-4  
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Section 2.2  
VALVE TRAIN  
VALVE CLEARANCE GV-220 ENGINE  
INTAKE VALVE: 0.001-0.0022 inch (0.03-0.056mm)  
EXHAUST VALVE: 0.0018-0.003 inch (0.046-0.07mm)  
Adjust the valve clearance as follows:  
1. Rotate the crankshaft until the piston is at top dead center  
(TDC) of its compression stroke. Both valves should be closed.  
2. Loosen the rocker arm jam nut.  
3. Use an alien wrench to turn the pivot ball stud while checking  
the clearance between the rocker arm and the valve stem with  
a feeler gauge.  
Figure 17. Tightening Pivot Ball Jam Nut  
Figure 16. Adjusting Valve Clearance  
4. When valve clearance is correct, hold the pivot ball stud with  
the alien wrench while tightening the rocker arm jam nut with a  
crow's foot. Tighten the jam nut to the specified torque. After  
tightening the jam nut, recheck the valve clearance to make  
sure it did not change.  
Figure 18. Rocker Arm Cover Installation  
JAM NUT TIGHTENING TORQUE  
GV-220: 6.3 foot-pounds  
ROCKER ARM COVER INSTALLATION  
Place a new rocker arm cover gasket into place.  
Then, install the rocker arm cover. Finally, retain the  
cover with M6-1.00 x 12mm screws.  
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Section 2.2  
VALVE TRAIN  
Page 2.2-6  
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Section 2.3  
PISTON, RINGS, CONNECTING ROD  
OVERSIZE PISTON & RINGS  
Worn or scored cylinders may be rebored to 0.010  
(0.25mm) or 0.020 (0.50mm) oversize. Pistons and  
piston rings of matching oversize are available to fit  
the rebored cylinder.  
F figure 2. Piston Pin Removal  
CHECK FOR PISTON WEAR:  
The piston is slightly elliptical. It's smaller diameter is  
in line with the wrist pin boss. It's larger diameter is  
90° from the wrist pin boss.  
NOTE: An assembly mark Is provided on the pis-  
ton. This mark should face the flywheel end of the  
crankshaft (3:00 position) during reassembly.  
Figure 1. Piston, Rings and Connecting Rod  
PRIOR TO REMOVAL  
Before removing pistons, rings and connecting rod,  
clean all carbon from the cylinder bore. Carbon  
buildup in the cylinder bore can cause ring breakage  
during piston removal.  
REMOVAL  
Remove the connecting rod CAP BOLTS and the  
connecting rod CAP. Then, push the piston and con-  
necting rod out through top of cylinder.  
Figure 3. Elliptical Shape of Piston  
PISTON  
To check the piston for wear, proceed as follows:  
REMOVE FROM CONNECTING ROD:  
1. Minor Diameter: At a position directly in line with the wrist pin  
hole, measure from top of piston down to a distance of 1.4-1.6  
inches (35.5-40.5mm). This is the "minor" diameter. Measure at  
this point to check for wear.  
NOTE: An oil hole in the wrist pin area of the pis-  
ton helps distribute oil to assist in cooling. The oil  
hole also provides an assist In removing the wrist  
pin snap ring.  
2. Major Diameter: At a point 90° from the wrist pin bore, measure  
down 1.4-1.6 inches (35.5-40.5mm). This is the "major" diame-  
ter. Measure at this point to check for piston wear. Replace the  
piston if wear limits are exceeded.  
To remove the piston from the connecting rod, pro-  
ceed as follows:  
1. Move the snap ring around until Its protruding end is aligned  
with the notched out oil hole. Use needle nose pliers to turn the  
snap ring and pull it toward you.  
3. Check wrist Pin for Looseness: A rough check for wear in the  
wrist pin, wrist pin bore in the piston, or wrist pin bore in the  
connecting rod is to check for looseness or play with the piston  
assembled to the rod. Looseness or play indicates a worn wrist  
pin, or a worn bore in the piston or connecting rod.  
2. With one snap ring removed, slide the wrist pin out of the pis-  
ton boss. This will separate the piston from the connecting rod.  
Page 2.3-1  
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Section 2.3  
PISTON, RINGS, CONNECTING ROD  
5. Ring to Groove Side Clearance:- Clean carbon from piston ring  
grooves as. Install new rings. Use a feeler gauge to measure the  
side clearance between the rings and ring grooves. If ring-to-  
groove side clearance exceeds the stated limits, replace the pis-  
ton.  
RING TO GROOVE SIDE CLEARANCE (GV-220)  
0.0004-0.0014 inch (0.012-0.034mm)  
Figure 4. Piston Minor Diameter  
PISTON MINOR DIAMETER GV-220)  
Design DIAMETER: 2.747-2.748 inch (69.789-69.809mm)  
Figure 6. Ring to Groove Side Clearance  
Figure 5. Piston Major Diameter  
PISTON MAJOR DIAMETER GV-220)  
Design DIAMETER: 2.753-2.754 inch (69.939-69.959mm)  
PISTON RINGS  
NOTE: Always apply engine oil to wrist pin and its  
bores during Installation. Wrist pin fit is very  
close.  
GENERAL:  
The following rules pertaining to piston rings must  
always be complied with:  
Always replace piston rings in sets.  
When removing rings, use a ring expander to pre-  
vent breakage. Do not spread the rings too far or  
they will break.  
When installing the piston into the cylinder, use a  
ring compressor. This wilt prevent ring breakage  
and/or cylinder damage.  
4. Check Wrist Pin for Wear: Measure the outside diameter of the  
wrist pin. Also measure the inside diameter of the wrist pin  
bore in the piston and in the connecting rod. Also check wrist  
pin length. Replace any component that Is worn excessively.  
WRIST PIN OUTSIDE DIAMETER (GV-220)  
DESIGN DIAMETER: 0.708-0.709 inch (17.989-18.000mm)  
WEAR LIMIT: 0.707 inch (17.969mm) Minimum  
WRIST PIN LENGTH (GV-220)  
DESIGN LENGTH: 2.196-2.213 inch (55.8-56.2mm)  
WEAR LIMIT: 2.193 inch (55.7mm) Minimum  
When installing new rings, deglaze the cylinder wall  
with a commercially available deglazing tool.  
WRIST PIN BORE IN PISTON (GV-220)  
DESIGN DIAMETER: 0.708-0.709 inch (18.000-18.011mm)  
WEAR LIMIT: 0.710 inch (18.026mm) Maximum  
RING DESCRIPTION:  
A piston ring SET consists of (a) a top compression  
ring, (b) a second compression ring, and (c) an oil  
ring assembly. When installing rings, pay close atten-  
tion to the following:  
The OIL RING is a 3-piece assembly which con-  
sists of two oil rails and an oil spacer ring. Oil rails  
have a rounded face and can be installed with  
either side up.  
CONNECTING ROD SMALL END I.D. (GV-220)  
DESIGN DIAMETER: 0.709-0.710 inch (18.02-18.03mm  
WEAR LIMIT: 0.711 inch (18.05mm) Maximum  
The second compression ring has an inside cham-  
fer which must face UP when installing the ring.  
The top compression ring has a barrel-shaped face  
and can be installed with either side up.  
Page 2.3-2  
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Section 2.3  
PISTON, RINGS, CONNECTING ROD  
CONNECTING ROD  
The connecting rod is manufactured of die cast alu-  
minum. Alignment marks are provided on the rod and  
on the connecting rod cap. Be sure to align these  
marks when assembling the rod to the crankshaft.  
Connecting rod bolts are of the "washerless" type.  
The connecting rod and the connecting rod cap are a  
matched set and must be replaced as a matched set.  
Figure 7. Ring Locations in Piston Grooves  
CHECKING PISTON RING END GAP:  
To check piston rings end gap, proceed as follows  
(see Figure 8):  
1. Locate a point inside the cylinder that is 2.75 inches (70mm)  
down from top of cylinder. This is approximately half-way  
down.  
Figure 9. Connecting Rod  
2. Place the ring into the cylinder. Use the piston to push the ring  
squarely into the cylinder to the proper depth.  
ASSEMBLY AND INSTALLATION  
3. Use a feeler gauge to measure the ring end gap. If end gap is  
excessive, rebore the cylinder to take oversize parts.  
ASSEMBLY:  
Use a ring expander when installing rings into the pis-  
ton ring grooves. Install the OIL RING ASSEMBLY  
first. Then, install the second compression ring with  
its Inside chamfer facing up. Finally, install the top  
compression ring.  
When assembling the piston, connecting rod and  
wrist pin, the assembly marks on the piston must be  
toward the flywheel side of the engine.  
Coat the wrist pin, wrist pin bore in piston, and wrist  
pin bore in the rod with engine oil. Install one snap  
ring into the piston's wrist pin bore. Then, assemble  
the piston to the rod. Slide the wrist pin through one  
piston bore, through the rod bore, and through the  
second piston bore until it contacts the snap ring.  
Then, install the second snap ring into the piston  
bore.  
TOP RING END GAP (GV-220)  
DESIGN GAP: 0.005-0.016 inch (0.15-0.40mm)  
WEAR LIMIT: 0.024 inch (0.60mm) Maximum  
SECOND RING END GAP (GV-220)  
DESIGN GAP: 0.006-0.016 inch (0.15-0.40mm)  
WEAR LIMIT: 0.024 inch (0.60mm) Maximum  
OIL RING END GAP (GV-220)  
DESIGN GAP: 0.015-0.055 inch (0.38-1.40mm)  
WEAR LIMIT: 0.062 inch (1.60mm) Maximum  
INSTALLATION:  
Coat the cylinder walls with engine oil, as well as the  
crank throw, connecting rod bearing and connecting  
rod cap bearing. Then, install the rod and piston  
assembly as follows:  
1. Use a ring compressor to compress the rings into the piston  
ring grooves. MAKE SURE ALL RINGS ARE FULLY COM-  
PRESSED INTO THEIR GROOVES.  
2. Guide the connecting rod into the cylinder, with assembly mark  
on piston toward the flywheel side of engine.  
Figure 8. Ring End Gap  
3. When the ring compressor contacts top of cylinder, use a wood  
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Section 2.3  
PISTON, RINGS, CONNECTING ROD  
hammer handle to gently tap the piston down into the cylinder.  
Always resize the cylinder bore to EXACTLY 0.010  
inch or 0.020 inch (0.25 or 0.50mm) over the stan-  
dard cylinder dimensions. If this Is done accurately,  
the service oversize ring and piston will fit and correct  
clearances will be maintained.  
4. Check that the connecting rod's large diameter bearing is coat-  
ed with oil, as well as the crank throw and the connecting rod  
cap.  
STANDARD CYLINDER BORE DIAMETER  
MINIMUM: 2.7560 inches (70.000mm)  
MAXIMUM: 2.7570 Inches (70.025mm)  
5. Guide the large end of the connecting rod onto the crankshaft.  
Install the connecting rod cap. The match mark on the cap  
must be aligned with an identical mark on the rod (Figure 10).  
To rebore the cylinder, use a commercial hone of  
suitable size chucked In a drill press having a spindle  
speed of about 600 rpm. Use the stones and lubrica-  
tion recommended by the hone manufacturer to pro-  
duce the proper cylinder bore finish. Proceed as fol-  
lows:  
6. Install the connecting rod cap bolts and tighten to the proper  
torque.  
TIGHTENING TORQUE  
CONNECTING ROD CAP BOLTS (GV-220)  
10 foot-pounds (1.36 N-m)  
1. Start with coarse stones. Center the cylinder under the drill  
press spindle. Lower the hone so that the lowest end of the  
stone contacts the lowest point in the cylinder bore.  
NOTE: The connecting rod can be installed in  
either direction. That is, the cap marks on the rod  
and cap may face toward the installer or away  
from the installer. The only requirement is that the  
assembly mark on top of piston be toward the fly-  
wheel side of engine.  
2. Begin honing at bottom of cylinder. Move the hone up or down  
at about 50 strokes per minute, to avoid cutting ridges In the  
cylinder wall. Every fourth or fifth stroke, move the hone far  
enough to extend it one (1) Inch beyond the top and bottom of  
the cylinder bore.  
3. Every 30 or 40 strokes, check the bore for size and straight-  
ness. If stones collect metal, clean them with a wire brush.  
4. Hone with coarse stones until the cylinder bore is within 0.002  
inch (0.05mm) of the desired finish size. Then, replace the  
coarse stones with burnishing stones and continue until bore is  
within 0.0005 inch (0.01 mm) of the desired size.  
5. Install finishing stones and polish the cylinder to its final size.  
6. Clean the cylinder with soap and water. Dry thoroughly.  
7. Replace the piston and rings with parts of correct oversize.  
Figure 10. Match Marks on Rod and Cap  
CYLINDER SERVICE  
INSPECTION:  
Check the cylinder for dirty, broken or cracked fins.  
Also look for worn or scored bearings, or a scored  
cylinder wall. Check the cylinder head mounting sur-  
face for warpage. If the head is warped, it must be  
replaced. If the cylinder bore is worn (as evidenced  
by excessive ring end gap), the cylinder should be  
replaced or rebored to 0.010 or 0.020 (0.25 or  
0.50mm) oversize.  
After reboring the cylinder to a specific oversize,  
install an identically oversize piston along with identi-  
cally oversized rings.  
Page 2.3-4  
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Section 2.4  
CRANKSHAFT AND CAMSHAFT  
GENERAL  
CRANKSHAFT REMOVAL  
Prior to removal of the crankcase cover, gain access  
to the engine and generator by removing surrounding  
sheet metal as required. See Section 1.6.  
See Figure 3. To remove the crankshaft, proceed as  
follows:  
1. The engine flywheel must be removed before the crankshaft  
can be removed.  
CRANKCASE COVER REMOVAL  
2. The piston and connecting rod must be removed.  
Before attempting to remove the crankcase cover,  
remove rust, paint and burrs from the power takeoff  
(PTO) end of the crankshaft. This will reduce the pos-  
sibility of damaging the oil seal in the crankcase cover  
or the bearing during cover removal.  
3. Remove the crankshaft by pulling it straight out of the  
crankcase.  
To remove the crankcase cover, proceed as follows:  
1. Drain oil from the crankcase.  
2. Remove the engine cylinder head, push rods and push rod  
guide plate. See Section 2.2.  
3. Remove all bolts that retain the crankcase cover to the  
crankcase.  
4. Remove the crankcase cover. If necessary, tap lightly with a  
soft hammer on alternate sides of the cover.  
Figure 2. Camshaft Removal  
Figure 1. Crankcase Cover Removal  
CAMSHAFT REMOVAL  
See Figure 2. Remove the camshaft as follows:  
1. Tip the engine over onto the flywheel end of the crankshaft.  
Support the engine to prevent end of crankshaft from resting  
on the workbench.  
Figure 3. Crankshaft Removal  
2. Reach in with two fingers and hold the tappets up so they are  
clear of the camshaft lobes. Then, remove the camshaft.  
3. Remove the two tappets.  
4. Remove the outer and inner oil pump rotors.  
(Continued)  
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Section 2.4  
CRANKSHAFT AND CAMSHAFT  
Inspect the crankpin for damage, nicks, scratches,  
etc. Small nicks and scratches may be polished out  
using fine emery cloth. ALL EMERY RESIDUE  
MUST BE REMOVED. Use a solvent (such as  
kerosene) to remove emery residue.  
CAMSHAFT INSPECTION  
Carefully inspect the entire camshaft for wear, nicks,  
damage. All areas indicated in Figure 4 should be  
checked for wear.  
Carefully measure the outside diameter (O.D.) of  
the crankpin, crankshaft journal at flywheel end,  
and crankshaft journal at PTO end. Replace the  
crankshaft if it is worn smaller than the stated limits.  
NOTE: DO NOT regrind the crankpin to any small-  
er diameter. Undersize connecting rods are NOT  
available for the GV-220 engines.  
Inspect oil passage. Use a length of wire to make  
sure it is open. Inspect threaded ends of crankshaft.  
CRANKPIN OUTSIDE DIAMETER  
DESIGN DIAMETER: 1.180-1.181 inch (29.99-30.01mm)  
WEAR LIMIT: 1.179 inch (29.96mm) Minimum  
CRANKSHAFT BEARING JOURNAL (FLYWHEEL END)  
DESIGN DIAMETER: 1.102-1.103 inch (28.000-28.012mm)  
WEAR LIMIT: 1.100 inch (27.95mm) Minimum  
CRANKSHAFT BEARING JOURNAL (PTO END)  
DESIGN DIAMETER: 1.102-1.103 inch (28.000-28.012mm)  
WEAR LIMIT: 1.186 inch (27.95mm) Minimum  
Figure 4. Points to Check on Camshaft  
The following should be measured carefully to check  
for wear:  
MAIN CAMSHAFT BEARING DIAMETER  
(FLYWHEEL END)  
DESIGN DIAMETER: 1.022-1.023 inch (25.96-25.98mm)  
WEAR LIMIT: 1.020 inch (25.91mm) Minimum  
MAIN CAMSHAFT BEARING DIAMETER (PTO END)  
DESIGN DIAMETER: 1.297-1.298 inch (32.96-32.98mm)  
WEAR LIMIT: 1.295 inch (32.89mm) Minimum  
CAMSHAFT BEARING BORE IN CRANKCASE  
DESIGN DIAMETER: 1.024-1.025 Inch (26.00-26.03mm)  
WEAR LIMIT 1.026 inch (26.06mm) Maximum  
CAMSHAFT BEARING BORE IN CRANKCASE COVER  
DESIGN DIAMETER: 1.299-1.300 inch (33.00-33.03mm)  
WEAR LIMIT: 1.302 inch (33.06mm) Maximum  
CAM LIFT  
DESIGN LIFT: 0.210-0.212 inch (5.34-5.38mm)  
WEAR LIMIT: 0.206 inch (5.24mm) Minimum  
Figure 5. Points to Check on Crankshaft  
Check the crankshaft bearing bore in the crankcase  
cover. If limits are exceeded, replace the crankcase  
cover.  
CRANKSHAFT INSPECTION  
CRANKSHAFT BEARING BORE IN CRANKCASE  
COVER  
DESIGN DIAMETER: 1.104-1.105 inch (28.040-28.065mm)  
WEAR LIMIT: 1.106 inch (28.092mm) Maximum  
CRANKSHAFT PROPER:  
Use a commercial solvent to clean the crankshaft.  
After cleaning, inspect the crankshaft as follows:  
Inspect keyways in crankshaft, make sure they are  
not worn or spread. Remove burrs from edges of  
keyway, to prevent scratching the bearing.  
Inspect timing gear teeth for chipping or cracking. If  
the timing gear is damaged, the crankshaft assem-  
bly must be replaced.  
Page 2.3-6  
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Section 2.4  
CRANKSHAFT AND CAMSHAFT  
Figure 8. Measuring Compression Release Lift  
Figure 6. Bearing Bore in Crankcase Cover  
INSTALLING THE CRANKSHAFT  
COMPRESSION RELEASE MECHANISM  
Before installing the crankshaft, lubricate all bearing  
surfaces with engine oil. Use oil seal protectors, to  
prevent damage to seals during installation. Install the  
crankshaft as follows:  
A mechanical compression release is provided on the  
camshaft. See Figure 7. A PIN extends over the cam  
lobe. This PIN pushes on the tappet, to lift the valve  
and relieve compression for easier cranking. When  
the engine starts, centrifugal force moves the FLY-  
WEIGHT outward against SPRING force. The PIN will  
then drop back and allow the engine to run at full  
compression.  
1. Lubricate all bearing surfaces with engine oil.  
2. Install the valve tappets.  
3. Support both ends of the crankshaft and carefully install into  
the crankcase.  
Measure the amount of compression release lift at the  
tappet (Figure 8).  
COMPRESSION RELEASE LIFT FOR GV-220 ENGINE  
(MEASURED AT TAPPET)  
4. Rotate the crankshaft until the timing mark (Figure 9) is toward  
the cam gear side of the crankcase.  
DESIGN LIFT: 0.020-0.047 inch (0.50-1.20mm)  
WEAR LIMIT: 0.016 inch (0.406mm) Minimum  
INSTALLING THE CAMSHAFT  
Apply engine oil to the camshaft main bearing and to  
bearing bore in crankcase. Carefully install the  
camshaft into the crankcase camshaft bore.  
Hold the tappets out of the way during installation.  
Align timing mark on camshaft gear with timing mark  
on crankshaft gear (piston will be at top dead center).  
See Figure 10.  
NOTE: For Installation of the oil pump assembly,  
oil pickup assembly and crankcase cover, see  
Part 5 "ENGINE OIL & COOLING SYSTEM".  
Figure 7. Compression Release Mechanism on  
Camshaft  
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Section 2.4  
CRANKSHAFT AND CAMSHAFT  
Figure 9. Timing Mark on Crankshaft Gear  
Figure 10. Alignment of Timing Marks  
Page 2.3-8  
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SECTION  
3.1  
TITLE  
PART 3  
GASOLINE FUEL  
SYSTEM  
INTRODUCTION TO FUEL SYSTEM  
3.2  
3.3  
3.4  
3.5  
3.6  
AIR CLEANER & AIR INTAKE  
FILTER & FUEL PUMP  
CARBURETOR  
AUTOMATIC CHOKE  
COMPUTER  
CONTROLLED  
VARIABLE  
SPEED CONTROL SYSTEM  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
Page 2  
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Section 3.1  
INTRODUCTION TO FUEL SYSTEM  
DANGER! THERE MUST BE NO LEAKAGE OF  
GASOLINE OR GASOLINE VAPORS INTO THE  
VEHICLE. THE GENERATOR COMPARTMENT  
MUST BE VAPOR-TIGHT TO PREVENT  
ENTRY OF FUEL VAPORS OR FUMES INTO  
THE VEHICLE. THE GENERATOR'S VENTILA-  
TION SYSTEM MUST PROVIDE A FLOW OF  
AIR THAT WILL EXPEL ANY FUEL VAPOR  
ACCUMULATIONS.  
GENERAL  
!
Recreational vehicle generators equipped with a  
gasoline fuel system are usually installed so that they  
share the fuel supply tank with the vehicle engine.  
When this is done, the generator Installer must never  
tee off the vehicle fuel supply line to deliver fuel to the  
generator.  
When the generator fuel supply line is teed off the  
vehicle's fuel supply line, the more powerful vehicle  
engine's fuel pump will starve the generator when  
both are running. In addition, when the vehicle engine  
is not running the generator fuel pump will draw all of  
the gasoline from the vehicle engine line or even from  
the vehicle engine carburetor. This will result in hard  
starting of the vehicle engine.  
One method of sharing the same fuel supply tank is to  
Install a special fitting at the tank outlet so that two  
fuel dip tubes can be fitted In the tank (Figure 1).  
Another method Is to install a new outlet In the tank. If  
the tank has an unused outlet, It can be used.  
A second fuel dip tube can be installed in the original  
tank outlet if the tank outlet is large enough to accom-  
modate two dip tubes. The required fittings can be  
made at a machine shop. To install a second fuel out-  
let on the tank means removing the tank to braze or  
weld a new fitting into place.  
RECOMMENDED FUEL  
Use a high quality UNLEADED gasoline. Leaded  
REGULAR grade gasoline is an acceptable substi-  
tute.  
Do NOT use any fuel containing alcohol, such as  
"gasohol". If gasoline containing alcohol is used, it  
must not contain more than 10% ethanol and it must  
be removed from the generator fuel system during  
storage. do NOT use fuel containing methanol. If any  
fuel containing alcohol Is used, the system must be  
inspected more frequently for leakage and other  
abnormalities.  
DANGER! ATTEMPTING TO WELD OR BRAZE  
ON A FUEL TANK, EMPTY OR NOT, IS  
EXTREMELY DANGEROUS. FUEL VAPORS IN  
!
THE TANK WILL RESULT IN AN EXPLOSION.  
The generator's fuel dip tube in the tank should be  
shorter than the vehicle engine's dip tube. This will  
prevent the generator from consuming the entire fuel  
supply.  
DANGER! THE FUEL SYSTEM DESIGNED  
AND INSTALLED BY THE GENERATOR MAN-  
UFACTURER IS IN STRICT COMPLIANCE  
!
WITH STANDARDS ESTABLISHED BY THE  
RECREATIONAL VEHICLE INDUSTRY ASSO-  
CIATION (RVIA). NOTHING MUST BE DONE  
DURING MAINTENANCE THAT WILL RENDER  
THE SYSTEM IN NON-COMPLIANCE WITH  
THOSE STANDARDS.  
Figure 1. Sharing a Fuel Supply Tank  
EVAPORATION CONTROL SYSTEMS  
Federal and state laws have imposed strict evapora-  
tive controls on gasoline fuel systems. The recreation-  
al vehicle industry has complied with such strict regu-  
lations by using specially designed fuel tanks, tank  
filler tubes and gas caps. Special canisters are often  
used to collect the gasoline vapors rather than let  
them escape into the atmosphere.  
Such systems are designed to operate within very  
critical pressure ranges. For that reason, the vehicle  
manufacturer's fuel supply system design must not be  
Page 3.1-1  
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Section 3.1  
INTRODUCTION TO FUEL SYSTEM  
altered. Service technicians working on the RV gener-  
ator systems must not do anything that might change  
the vehicle fuel system design.  
Figure 2. Typical Gasoline Fuel System  
Page 3.1-2  
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Section 3.2  
AIR CLEANER AND INTAKE  
4. Clean the air cleaner BASE and COVER, then install the new  
PAPER FILTER Into COVER.  
AIR CLEANER  
DESCRIPTION:  
5. Install COVER with PAPER FILTER. Retain to BASE with two  
screws.  
The air cleaner assembly consists of (a) an air clean-  
er BASE, (b) a PAPER FILTER, and (c) a COVER.  
See Figure 1.  
AIR INTAKE  
See Figure 2. Air is drawn into the air cleaner, passes  
through the air cleaner filter, and is then ported to the  
carburetor air inlet through an air intake hose.  
Periodically inspect the air intake hose for condition,  
damage, holes, perforations, etc. Replace hose, if  
necessary. Inspect air intake hose clamps for tight-  
ness, condition. Tighten or replace as necessary.  
Figure 1. Engine Air Cleaner  
SERVICING THE AIR CLEANER:  
Clean or replace the PAPER FILTER every 25 hours  
of operation or once each year, whichever comes  
first.  
Figure 2. Air Intake Components  
1. Loosen the two screws that retain the air cleaner COVER and  
remove the COVER.  
2. Remove the PAPER FILTER.  
3. Clean the PAPER FILTER by tapping gently on a flat surface. If  
PAPER FILTER is extremely dirty, replace it.  
Page 3.2-1  
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Section 3.2  
AIR CLEANER AND INTAKE  
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Section 3.3  
FUEL FILTER AND FUEL PUMP  
TESTING THE PUMP:  
FUEL FILTER  
1. The pump coil can be tested for an open or shorted condition  
as follows:  
The fuel filter should be removed and replaced every  
100 hours of operation or once each year, whichever  
occurs first.  
a.Test for "Open":  
(1) Disconnect the RED pump wire at its "bul-  
let" lug.  
(2) Set a VOM to its "Rx1 " scale and zero the  
meter.  
(3) Connect one meter test probe to the RED  
pump wire, the other test probe to terminal  
end of the pump's BLACK lead. The VOM  
should Indicate pump coil resistance.  
FUEL PUMP NOMINAL COIL RESISTANCE  
ABOUT 29.5 kW  
b.Test for "Shorted" condition:  
(1) Disconnect the RED and the BLACK fuel  
pump leads.  
(2) Set a VOM to its "Rx10,000" or "Rx1 K"  
scale and zero the meter.  
Figure 1. Fuel Filter (Typical)  
(3) Connect one VOM test lead to the pump  
RED lead, the other test probe to the pump  
body. The meter should read "infinity".  
FUEL PUMP  
DESCRIPTION:  
2. Pump operation can be tested as follows:  
The 12 volts DC electric fuel pump has a zinc plate  
finish. Flow through the pump is positively shut off  
when It is not operating. The pump is actually rated at  
a voltage of 8 to 16 VDC, but has a nominal voltage  
rating of 12 VDC.  
a.Disconnect the fuel line from the outlet side of  
the fuel pump.  
b.Make sure a supply of fuel is available to the  
Inlet side of the pump.  
c. The RED lead from the pump must be connect-  
ed properly into the circuit The pump's BLACK  
lead must be connected at the pump mounting  
bolt.  
Current draw of the pump at nominal voltage is  
approximately 1.4 amperes maximum.  
Pressure rating of the pump at zero delivery is 2.0 to  
3.5 psi.  
Two wires are brought out from the pump. The black  
wire Is grounded by connecting it to a pump mounting  
bolt The red wire Is identified as Wire No. 14A. The  
pump will operate whenever:  
d.Actuate the Fuel Prime switch on the generator  
panel. The pump should operate and should  
pump fuel from the outlet side.  
NOTE: If desired, a pressure gauge can be  
attached to the pump's outlet side. Pump outlet  
pressure should be 2.0 to 3.5 psi.  
The FUEL PRIME switch on the generator panel is  
actuated to its "ON" position.  
During engine startup and running conditions when  
the A6060 circuit board energizes the Wire No. 14  
circuit.  
Figure 2. Electric Fuel Pump  
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Section 3.3  
FUEL FILTER AND FUEL PUMP  
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Section 3.4  
CARBURETOR  
GENERAL INFORMATION  
CARBURETOR OPERATION  
Proper engine performance depends on the carbure-  
tion system. The use of clean, fresh gasoline and a  
well-maintained air cleaner are extremely important to  
proper operation, as well as engine reliability and  
power.  
FLOAT OPERATION:  
A hollow plastic float maintains fuel level in the float  
bowl. As fuel is used, the float moves downward to  
move an inlet needle valve off its seat.  
Most causes of carburetion problems are related to  
the use of stale, gummy fuel and the ingestion of dirt.  
Before servicing the carburetor, be sure to check for  
evidence of these conditions. Gasoline that is left in  
the fuel lines for long periods can form gum or varnish  
deposits that will adversely affect carburetor opera-  
tion.  
When the needle valve moves off its seat, fuel can  
flow into the bowl. As the fuel level rises, the float  
moves upward to force the needle valve against its  
seat and stop the flow into the bowl.  
NOTE: A commercial fuel stabilizer (such as STA-  
BIL®) will minimize the formation of um deposits  
during storage. Add the stabilizer- to the gasoline  
In the fuel tank or In the storage container. Follow  
the ratio recommended on the stabilizer contain-  
er. Run the engine for about 10 minutes after  
adding stabilizer, to allow It to enter the carbure-  
tor. "STABIL®" Is a brand name fuel stabilizer that  
can be purchased In most automotive repair facili-  
ties or in lawn and garden centers.  
DESCRIPTION  
The carburetor used on GV-220 engines is a float type  
with fixed main jet. Carburetor throttle position and  
engine speed are controlled by an electric stepper  
motor. The stepper motor moves the throttle in  
response to signals received from the A6060 circuit  
board. The circuit board senses load voltage, establish-  
es the correct engine speed to obtain correct voltage  
and delivers an output signal to the stepper motor. The  
stepper motor adjusts the engine throttle to change  
engine speed and establish correct output voltage.  
Figure 2. Carburetor Sectional View  
CHOKE POSITION:  
The choke valve is closed to restrict the flow of air  
into the engine. As the engine cranks, air pressure in  
the cylinder is reduced. Since the air intake passage  
is partially blocked by the choke valve, fuel is drawn  
from the main nozzle and from the idle discharge port.  
This creates the very rich fuel mixture required for  
starting a cold engine.  
IDLE OPERATION:  
The throttle valve is nearly closed to shut off the fuel  
supply from all ports except the primary idle fuel dis-  
charge port. Engine suction then draws fuel only from  
that port.  
HIGH SPEED OPERATION:  
The throttle valve is wide open. This allows a large  
volume of air to pass through the carburetor at a high  
velocity. The high velocity air flow past the carburetor  
venturi results in a drop in air pressure at the venturi  
throat. This reduced air pressure draws fuel through  
the main nozzle that opens into the venturi which then  
mixes with the air in the air passage.  
Figure 1. Carburetor  
Page 3.4-1  
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Section 3.4  
CARBURETOR  
CARBURETOR DISASSEMBLY  
See Figure 3. The carburetor can be disassembled as  
follows:  
1. Remove the BOWL NUT (Item 3) and the FIBER WASHER  
(Item 4). Then, remove the FLOAT BOWL (Item 5).  
2. Remove the FLOAT PIN (Item 6). Then, remove the FLOAT  
(Item 7) and the INLET VALVE (Item 8).  
3. Remove the IDLE SPEED SCREW (Item 20) with SPRING  
(Item 19).  
4. Rotate the THROTTLE VALVE (Item 10) to its closed position  
and remove the SCREW (Item 9). Remove the THROTTLE  
VALVE.  
5. Remove the THROTTLE SHAFT (Item 14), along with the  
THROTTLE SHAFT SPRING (Item 13) and the THROTTLE  
SHAFT SEAL (Item 12).  
6. Remove the CHOKE VALVE SPRING RETAINER (Item 18).  
Remove the CHOKE VALVE (Item 17). Remove the CHOKE  
SHAFT (Item 15) and the SHAFT SEAL (Item 16).  
CLEANING AND INSPECTION  
1. Separate all non-metallic parts.  
2. Clean metallic parts in a solvent or a commercial cleaner. Soak  
the parts no longer than about 30 minutes.  
3. Inspect throttle lever and plate. Replace if worn or damaged.  
4. The float bowl must be free of dirt and corrosion. Use a new  
float bowl gasket when assembling the bowl.  
Figure 3. Carburetor Exploded View  
3. Bowl Nut  
5. Check the float for damage. Replace, If damaged. The float  
setting is fixed and non-adjustable.  
4. Fiber Washer  
5. Float Bowl  
6. Float Pin  
6. The carburetor body contains a main jet tube that is pressed in  
to a fixed depth. Do NOT attempt to remove this tube. Tube  
movement will adversely affect carburetor metering character-  
istics.  
7. Float  
8. Inlet Valve  
9. Screw  
10. Throttle Valve  
11. Body  
12. Throttle Shaft Seal  
13. Throttle Shaft Spring  
14. Throttle Shaft  
15. Choke Shaft  
16. Choke Shaft Seal  
17. Choke Valve  
18. Choke Valve Spring Retainer  
19. Idle Speed Screw Spring  
20. Idle Speed Screw  
7. After soaking in solvent, blow out all passages with com-  
pressed air.  
Page 3.4-2  
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Section 3.4  
CARBURETOR  
ADJUSTMENT  
The carburetor used on the GV-220 engine has a  
FIXED, NON-ADJUSTABLE Low Speed Jet.  
ENGINE SPEED  
Engine speed is controlled by the A6060 circuit board.  
That circuit board signals a stepper motor which  
moves the throttle linkage. Engine speed will vary in  
response to changes in generator AC output voltage.  
The circuit board monitors the demand for power and  
adjusts the engine speed accordingly. This permits  
the engine to deliver only the power needed.  
NOTE: Do NOT attempt to accelerate the engine  
manually by, grasping the throttle or throttle link-  
age. This win cause the system to enter a fault  
condition and terminate generator AC output.  
Figure 4. Set Gap Between Stop Tab and Stop Block  
THROTTLE LINKAGE ADJUSTMENT  
If necessary, the length of the linkage between the  
stepper motor and the carburetor throttle lever arm  
can be adjusted. This adjustment helps to establish  
the proper travel relationship of the linkage. If the  
adjustment is not correct, the A6060 board will not be  
able to control the full range of engine speed. The fol-  
lowing conditions might occur:  
If the throttle linkage is set too short, the system will  
not be able to provide wide open throttle or full  
power conditions.  
If the linkage is set too long, the system will not be  
able to provide closed throttle or no power condi-  
tions.  
Use the following procedure to ensure the linkage rod  
is properly adjusted:  
1. Start the engine and immediately shut it down. As the engine  
coasts to a stop, observe from above the engine as the carbu-  
retor throttle lever rotates counterclockwise.  
Figure 5. Adjusting Throttle Linkage  
2. There should be a gap of about 0.003 inch (0.08-0.5mm)  
between the stop tab on the throttle lever arm and the stop  
block on the carburetor casting. See Figure 4.  
CARBURETOR REMOVAL  
To remove the carburetor from the engine, proceed  
as follows (see Figure 6, next page):  
CAUTION! The next step involves bending a  
spring clip. Do NOT overbend the clip or it  
may lose its clamping force.  
1. Disconnect the carburetor fuel inlet line.  
!
2. Loosen the clamp and disconnect the carburetor air inlet hose.  
3. Remove the two M6-1.00 x 90mm screws that retain the carbu-  
retor.  
3. Use pliers to lightly compress the spring clip on the carburetor  
lever arm (Figure 5). This permits the linkage rod to slide freely  
through the clip. With the clip compressed, rotate the throttle  
lever in the appropriate direction until there is a 0.003 inch  
(0.08-0.5mm) gap.  
4. Remove the carburetor air inlet adapter, the air inlet adapter  
gasket, carburetor and carburetor to skirt gasket.  
5. Remove the sheet metal carburetor skirt.  
4. Release the spring clip to lock in the adjustment.  
6. Remove two gaskets and the carburetor spacer.  
Page 3.4-3  
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Section 3.4  
CARBURETOR  
Figure 6. Carburetor Removal  
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Section 3.5  
AUTOMATIC CHOKE  
GENERAL  
OPERATIONAL CHECK AND ADJUSTMENT  
The GV-220 vertical shaft engines are equipped with  
an automatic choke. A choke solenoid is attached to  
the carburetor choke shaft by means of a choke con-  
trol link. Solenoid operation is controlled by the A6060  
circuit board. The circuit board energizes and de-  
energizes the solenoid cyclically at a rate dependent  
on ambient temperature during engine cranking only.  
OPERATIONAL CHECK:  
Crank the engine. During cranking, the choke sole-  
noid should pull in about every 2 to 5 seconds. If it  
does NOT pull in, try adjusting the choke.  
PRE-CHOKE ADJUSTMENT:  
With the solenoid NOT pulled in, the carburetor choke  
valve (choke plate) should be about 1/8 inch from its  
full open position. If necessary, use needle nose pli-  
ers to bend the tip of the BI-METAL until a 1/8 inch  
setting is obtained.  
DESCRIPTION  
See Figure 1. The CHOKE SOLENOID is retained to  
a CHOKE COVER by two No. 4-40 SCREWS, LOCK-  
WASHERS and FLATWASHERS. The two screw  
holes in the COVER are slotted to provide for axial  
adjustment of the CHOKE SOLENOID. A COTTER  
PIN retains a CHOKE LINK to the SOLENOID. A  
CHOKE BI-METAL & HEATER is retained to the  
SOLENOID by two No. 4-40 SCREWS, LOCKWASH-  
ERS and FLATWASHERS.  
CHOKE SOLENOID ADJUSTMENT:  
Loosen the two screws that retain the choke solenoid  
to its cover. Adjust axial movement of the solenoid  
plunger by sliding the solenoid in the slotted screw  
holes of the cover.  
Adjust plunger axial movement until (with the carbure-  
tor choke valve closed) the plunger is bottomed in the  
solenoid coil. That is, until the plunger is at its full  
actuated position.  
With the choke valve (choke plate) closed and the  
plunger bottomed in its coil, tighten the two screws.  
Figure 1. Choke Solenoid Parts  
OPERATION  
NOTE: Also see Part 6, "ENGINE ELECTRICAL  
SYSTEM". The section on DC control system  
includes additional information on choke opera-  
tion and the A6060 circuit board.  
Figure 2. Choke Adjustment  
When the engine is being cranked, A6060 circuit  
board action energizes the choke solenoid in regular  
timed cycles. Each time the choke solenoid is ener-  
gized, it closes the carburetor choke valve. The circuit  
board's choke timer circuit energizes the choke sole-  
noid (pulls it in) about every 2 to 5 seconds.  
When the engine starts, cranking is terminated. The  
choke action is then terminated and the choke setting  
is determined by a choke heater (CH).  
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Section 3.5  
AUTOMATIC CHOKE  
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Section 3.6  
SPEED CONTROL SYSTEM  
Electrical connections to stepper motor broken or  
disconnected.  
GENERAL  
The AC generator's output voltage is controlled by a  
"computerized" speed control system. This system  
changes engine speed in response to changes in the  
AC output voltage at varying engine loads. The speed  
control system consists of (a) the A6060 circuit board  
and (b) a stepper motor.  
Electrical leads to stepper motor are connected  
wrong.  
THROTTLE LINKAGE:  
Check throttle linkage and carburetor throttle shaft for  
binding, disconnected linkage. This type of problem  
will usually result in the carburetor throttle lever not  
moving. If the throttle lever does not move, the throttle  
may be stuck at a permanently open throttle or a per-  
manently closed throttle as follows:  
A6060 CIRCUIT BOARD  
This circuit board utilizes a closed-loop, proportional-  
derivative controller circuit which regulates the gener-  
ator's RMS voltage by changing engine speed. The  
system attempts to maintain an output voltage of  
about 115 volts at the lowest rpm and 120 volts up to  
the maximum rpm.  
The A6060 circuit board controls a stepper motor by  
calculating the number of steps the motor needs to  
take and then supplying the necessary signals to the  
motor to take those steps.  
1. If the throttle is open, engine will start but will accelerate quick-  
ly and uncontrollably. It will shut down when speed exceeds  
about 4200 rpm.  
2. If the throttle is closed, engine will not accelerate under load.  
STEPPER MOTOR FAILED OR SEIZED:  
The engine will start but stepper motor will not turn. If  
an open throttle condition exists, either of the follow-  
ing might occur:  
STEPPER MOTOR PROBLEMS  
1. Engine may accelerate and shut down at 4200 rpm.  
2. Engine may shut down after 15 seconds due to an overvoltage  
condition.  
INTRODUCTION:  
Some stepper motor problems that might occur  
include the following:  
Throttle linkage or carburetor throttle shaft sticking,  
or linkage disconnected.  
If throttle is closed, engine will be unable to acceler-  
ate under load and AC output will be low.  
A failed stepper motor may also turn erratically. If this  
is the case, engine speed and AC output voltage will  
be erratic under constant load.  
Stepper motor failed or seized.  
Figure 1. Speed Control System  
Page 3.6-1  
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Section 3.6  
SPEED CONTROL SYSTEM  
ELECTRICAL CONNECTIONS BROKEN:  
Approximately 19-21 ohms should be  
indicated.  
If one or more of the electrical connections to the  
stepper motor are broken or disconnected, either of  
the following might occur:  
b.To the YELLOW wire connector pin. About 19-  
21 ohms should be read.  
1. The stepper motor may not turn at all.  
c. To the BROWN wire pin for a reading of 19-21  
ohms.  
2. The stepper motor may turn erratically.  
d.To the BLACK wire connector pin for a reading  
of about 19-21 ohms.  
If the stepper motor does not turn, symptoms will be  
the same as for a failed or seized stepper motor.  
LEADS CONNECTED WRONG:  
TESTING FOR SHORTED CONDITION:  
Incorrectly connected electrical leads to the stepper  
motor can result in any one of the following:  
1. Set the VOM to its "Rx10,000" or "Rx1 K" scale and zero the  
meter.  
1. Stepper motor may not turn at all.  
2. Stepper motor may turn erratically.  
3. Stepper motor may turn backwards.  
2. Connect one VOM test probe to the RED wire connector pin,  
the other test probe to the Stepper Motor case. The meter  
should read infinity". Any reading other than "infinity" indicates  
a shorted winding.  
If the stepper motor does not turn, engine will start  
and the following may occur:  
Replace the Stepper Motor if it fails any part of the  
test.  
1. If throttle is open, engine will accelerate and shut down when  
speed reaches 4200 rpm or after 15 seconds due to overvolt-  
age condition.  
2. If throttle is closed, engine will be unable to accelerate under  
load.  
If the stepper motor turns erratically, engine speed  
and AC output voltage will be erratic under a constant  
load. The AC output will not terminate.  
If the stepper motor is turning backwards, engine will  
accelerate and shut down at 4200 rpm.  
Figure 2. The Stepper Motor Connector  
TESTING THE STEPPER MOTOR  
GENERAL:  
The Stepper Motor consists of an electric motor plus  
a small gearbox. It is shown pictorially and schemati-  
cally in Figure 3. The four (4) motor windings can be  
tested for (a) continuity and (b) shorts to the case.  
It is difficult to perform an operational test of the  
motor since the amount of motor arm movement is so  
small.  
TESTING FOR OPEN CONDITION:  
To test the motor windings for an open circuit condi-  
tion, proceed as follows:  
1. Unplug the Stepper Motor connector from its receptacle on the  
A6060 circuit board.  
2. Set a volt-ohm-milliammeter (VOM) to its "Rx1" scale and zero  
the meter.  
3. Connect one VOM test probe to the connector pin to which the  
RED wire attaches. This is the +DC side of all windings. Then,  
connect the other VOM test probe as follows:  
Figure 3. The Stepper Motor  
a.To the ORANGE wire connector pin.  
Page 3.6-2  
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PART 4  
GASEOUS FUEL  
SYSTEM  
SECTION  
4.1  
TITLE  
INTRODUCTION TO FUEL SYSTEM  
4.2  
4.3  
SHUTOFF VALVE & REGULATOR  
CARBURETOR  
NOTE: Information on the following is the same as  
for the "GASOLINE FUEL SYSTEM" (Part 3):  
Air Cleaner & Air Intake (Section 3.2)  
COMPUTER  
CONTROLLED  
VARIABLE  
Speed Control System (Section 3.6)  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Section 4.1  
INTRODUCTION TO FUEL SYSTEM  
A nearly homogeneous mixture in the engine  
cylinders.  
GENERAL INFORMATION  
Some RV generator models are equipped with fuel  
systems that utilize LP gas as a fuel. The initials "LP"  
stand for "liquefied petroleum". This gas is highly  
volatile and can be dangerous if handled or stored  
carelessly.  
Fuel can be stored for long periods without break-  
down.  
FUEL SYSTEM COMPONENTS  
All applicable laws, codes and regulations pertaining  
to the storage and handling of LP gas must be com-  
plied with. The installation of such fuel systems must  
also be in compliance with such laws, codes and reg-  
ulations. Service technicians who work on these sys-  
tems must do nothing that might cause the system to  
be in non-compliance with regulations.  
Regulations established by the Recreational Vehicle  
Industry Association (RVIA) must be followed in the  
installation, use and servicing of such systems.  
When the generator set is shipped from the factory,  
the following fuel system components are included  
with the unit:  
1. A Fuel Lockoff Solenoid  
2. The LP Gas Regulator  
3. The carburetor.  
4. Interconnecting lines and fittings.  
DANGER! LP GAS IS HIGHLY EXPLOSIVE.  
THE GAS IS HEAVIER THAN AIR AND  
Components that must be added by the generator  
installer include the following:  
!
TENDS TO SETTLE IN LOW AREAS. EVEN  
THE LIGHTEST SPARK CAN IGNITE THE  
GAS AND CAUSE AN EXPLOSION. ONLY  
COMPETENT, QUALIFIED GAS SERVICE  
TECHNICIANS SHOULD BE ALLOWED TO  
INSTALL, TEST, ADJUST OR SERVICE THE  
GASEOUS FUEL SYSTEM. INSTALLATION  
OF A GASEOUS FUEL SYSTEM MUST BE  
IN STRICT COMPLIANCE WITH APPLICA-  
BLE CODES. FOLLOWING INSTALLATION  
NOTHING MUST BE DONE THAT MIGHT  
RENDER THE SYSTEM IN NONCOMPLI-  
ANCE WITH SUCH CODES.  
1. A VAPOR WITHDRAWAL type fuel tank.  
2. A PRIMARY REGULATOR that will deliver a fuel pressure to  
the Fuel Lockoff Solenoid of about 11water column.  
3. Interconnecting lines and fittings.  
VAPOR WITHDRAWAL  
LP gas is stored in pressure tanks as a liquid.  
Gaseous fuel system components installed on the  
generator are designed for "vapor withdrawal" type  
systems. Such systems use the gas vapors that  
form above the liquid fuel in the tank. Do not attempt  
to use any "liquid withdrawal" type tank with the RV  
generator.  
NOTE: "Liquid withdrawal" type systems use the  
liquid fuel from the tank. The liquid fuel must be  
vaporized before it reaches the carburetor. Fuel  
vaporization is usually accomplished by porting  
the liquid fuel through some kind of heating  
device.  
DANGER! USE ONLY APPROVED COMPO-  
NENTS IN THE GASEOUS FUEL SYSTEM.  
IMPROPER INSTALLATION OR USE OF  
UNAUTHORIZED COMPONENTS CAN  
RESULT IN FIRE OR AN EXPLOSION. USE  
APPROVED METHODS TO TEST THE SYS-  
TEM FOR LEAKS. NO LEAKAGE IS PERMIT-  
TED. DO NOT PERMIT FUEL VAPORS TO  
ENTER THE VEHICLE INTERIOR.  
!
IMPORTANT CONSIDERATIONS  
ADVANTAGES OF GASEOUS FUELS  
When servicing the gaseous fuel system the following  
rules apply:  
All lines, fittings, hoses and clamps must be free of  
leaks. Apply pipe sealant to threads when assem-  
bling threaded connectors to reduce the possibility  
of leakage.  
Following any service, the system must be tested  
for leaks using APPROVED test methods.  
Optimum gas pressure at the inlet to the fuel lock-  
off solenoid and secondary regulator is 11 inches  
of water column. Do NOT exceed 14 inches water  
column.  
The use of gaseous fuels may result in a slight power  
loss, as compared to gasoline. However, that disad-  
vantage is usually compensated for by the many  
advantages of gaseous fuels. Some of these advan-  
tages are:  
A low residue content results in minimum carbon  
formation in the engine.  
Reduced sludge buildup in the engine oil.  
Reduced burning of valves as compared to gasoline.  
No wash-down of engine cylinder walls during  
cranking and startup.  
Excellent anti-knock qualities.  
Page 4.1-1  
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Section 4.1  
INTRODUCTION TO FUEL SYSTEM  
Gaseous fuel lines and primary regulators must be  
properly sized to deliver adequate fuel flow to the  
generator engine. The generator requires at least  
67 cubic feet of gas per hour for its operation.  
IMPORTANT CONSIDERATIONS (CONTINUED)  
NOTE: A PRIMARY REGULATOR, between the  
tank and the fuel lockoff solenoid, is required to  
ensure that correct gas pressure is delivered to  
the lockoff solenoid.  
The generator installer's connection point is at the  
fuel lockoff solenoid which has a 3/4 inch (female)  
connection.  
A length of flexible hose is required between the  
fuel lockoff solenoid and rigid fuel piping, to allow  
for vibration and/or shifting of the unit. This line  
must be at least six (6) inches longer than neces-  
sary.  
NOTE: An existing primary regulator may be used  
to deliver gas to the fuel lockoff solenoid provid-  
ed It has sufficient flow capacity for the generator  
and other gas appliances in the circuit. If the  
existing primary regulator does not have a suffi-  
cient capacity (a) replace it with one that has ade-  
quate flow capacity, or (b) install a separate pri-  
mary regulator having at least a 67 cubic feet per  
hour capacity.  
EXCESS FLOW VALVE  
FUEL SUPPLY LINES  
Rules established by the National Fire Protection  
Association (NFPA) and the Recreation Vehicle  
Industry Association (RVIA) require that the LP gas  
tank be equipped with an excess flow valve. This  
valve and the gaseous fuel lines must be carefully  
sized so the excess flow valve will close in the event  
of line breakage.  
Shutoff valves on the fuel supply tank and elsewhere  
in the system must be fully open when operating the  
generator. The excess flow valve will function proper-  
ly only if all valves are fully open and fuel lines are  
properly sized.  
When servicing or repairing the gaseous fuel system,  
the following rules apply to gaseous fuel supply lines:  
The LP gas lines must be accessible but must also  
be protected against possible damage.  
Do NOT connect electrical wiring to any gaseous  
fuel line. Do NOT route electrical wiring alongside  
the gaseous fuel lines.  
Route the gaseous fuel lines AWAY from hot  
engine exhaust mufflers and piping.  
Gas lines should be retained with metal clamps that  
do not have any sharp edges.  
Figure 1. A Typical LP Gas Fuel System  
Page 4.1-2  
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Section 4.1  
INTRODUCTION TO FUEL SYSTEM  
GASEOUS CARBURETION  
LEAKAGE TESTING  
Gas at positive pressure is delivered from the fuel  
lockoff solenoid to the inlet of the regulator (about 11-  
14 inches of water).  
As the engine piston moves downward on its intake  
stroke, air is drawn into the area above the piston  
through the carburetor venturi. A negative pressure is  
created at the venturi which is proportional to the  
amount of air that is flowing.  
Whenever any lines, fittings or other components of  
the fuel system have been removed and replaced, the  
system should be carefully checked for leaks before it  
is placed into service.  
To check for leakage, start the engine and let it run.  
Then use a soap and water solution or an approved  
commercial leak detector solution to determine if any  
leakage exists. No leakage is permitted.  
The negative pressure at the carburetor venturi acts  
on the regulator diaphragm to pull the diaphragm  
toward the source of low pressure. A lever, attached  
to the diaphragm, opens a metering valve which  
allows gas to enter and flow through the carburetor.  
The greater the air flow through the carburetor ven-  
turi, the lower the pressure at the venturi throat. The  
lower the pressure at the venturi throat, the greater  
the movement of the diaphragm and the more the  
metering valve opens.  
DANGER! DO NOT USE FLAME TO CHECK  
FOR LEAKAGE. GASEOUS FUEL LINES  
BETWEEN THE TANK AND SECONDARY  
!
REGULATOR ARE UNDER A POSITIVE PRES-  
SURE (ABOUT 11 INCHES OF WATER COL-  
UMN). HOWEVER, GAS PRESSURE AT THE  
OUTLET SIDE OF THE SECONDARY REGU-  
LATOR IS A NEGATIVE PRESSURE (ABOUT 1  
INCH WATER COLUMN). THIS NEGATIVE  
PRESSURE CAN DRAW FLAME INSIDE A  
LINE OR FITTING AND CAUSE AN EXPLO-  
SION.  
IMPORTANT! APPLY PIPE SEALANT TO  
THREADS OF ALL FITTINGS TO REDUCE  
THE POSSIBILITY OF LEAKAGE.  
!
Figure 2. Gas Carburetion Diagram  
The following requirements of the secondary regulator  
must be emphasized:  
It must be sensitive to pressure changes in the car-  
buretor venturi throughout the entire operating  
range.  
It must positively stop the flow of gas when the  
engine is not running.  
The slightest air flow through the carburetor venturi  
must move the regulator valve off its seat and per-  
mit gas flow.  
Page 4.1-3  
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Section 4.1  
INTRODUCTION TO FUEL SYSTEM  
Page 4.1-4  
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Section 4.2  
SHUTOFF VALVE AND REGULATOR  
GENERAL  
ADJUSTMENTS  
See Figure 1. The fuel shutoff valve (lockoff solenoid)  
and the secondary regulator are retained to a flat  
mounting bracket which, in turn, mounts to the gener-  
ator base cover. The fuel lockoff solenoid is retained  
to the mounting bracket by means of a u-bolt. The  
secondary regulator is retained to the mounting  
bracket with two 1/4"-20 x 3/4" long capscrews.  
There are no adjustments on the fuel lockoff solenoid  
or the secondary regulator. This system is NOT  
equipped with a load block.  
THE LP GAS REGULATOR  
The secondary regulator is a GARRETSON® Model  
KN. It is designed for simplicity and simple operation.  
The regulator is suitable for use with low pressure  
vaporized gaseous fuels where dependable starting is  
a requirement. Recommended inlet pressure to the  
regulator is 11 inches water column.  
The regulator comes with a 3l4 inch NPT fuel inlet  
and a 3/8 inch NPT fuel outlet.  
The LOCKOFF ADJUSTMENT SCREW shown in  
Figure 2 has been preset at the factory. No additional  
adjustment is authorized.  
ITEM  
1
QTY  
1
DESCRIPTION  
LP Gas Regulator  
2
1
Fuel Lockoff Solenoid  
U-Bolt-1.25" wide (5/16"-i 8)  
3/4" NPT Street Elbow  
3/4" NPT Close Nipple  
3/8" NPT Street Elbow  
1/2" x 3/8" NPT Fitting  
Hose Clamp  
3
1
4
2
5
1
6
1
7
1
8
1
9
1
1/2" ID Hose (11.5" long)  
1/4"-20 x 3/4" Capscrew  
1/4" Lockwasher  
10  
11  
12  
13  
14  
15  
2
2
2
5/16" Lockwasher  
2
5/16"-18 Hex Nut  
1
Regulator Mounting Bracket  
Sleeving (9" long)  
1
Figure 2. LP Gas Regulator  
DANGER! DO NOT ATTEMPT TO ADJUST  
THE GAS REGULATOR. REGULATOR  
ADJUSTMENTS SHOULD BE ATTEMPTED  
ONLY BY QUALIFIED GAS SERVICE TECHNI-  
CIANS WHO HAVE THE KNOWLEDGE AND  
SPECIALIZED EQUIPMENT FOR SUCH  
ADJUSTMENTS.  
!
TESTING THE FUEL LOCKOFF SOLENOID  
GENERAL:  
The fuel lockoff solenoid is energized open by 12  
volts DC power from the A6060 circuit board during  
engine cranking. The solenoid can also be energized  
open without cranking by actuating the fuel primer  
switch on the generator panel.  
Figure 1. Shutoff Valve & Regulator  
(Continued)  
Page 4.2-1  
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Section 4.2  
SHUTOFF VALVE AND REGULATOR  
TEST PROCEDURE:  
1. Set a volt-ohm-milliammeter (VOM) to read battery voltage (12  
VDC).  
2. Connect the VOM test leads across Wire 14 (Red) at the sole-  
noid and a clean frame ground. 3. Set the fuel primer switch on  
the generator panel to its ON position. a. The meter should  
indicate battery voltage. b. The solenoid should energize open.  
RESULTS OF TEST:  
1. If battery voltage is Indicated but the solenoid does NOT ener-  
gize, replace the lockoff solenoid.  
2. If battery voltage is NOT Indicated, a problem exists In the DC  
control system. See Parts 6, "ENGINE ELECTRICAL SYS-  
TEM".  
Figure 3. Fuel Lockoff Solenoid  
Page 4.2-2  
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Section 4.3  
CARBURETOR  
GENERAL  
DISASSEMBLY AND REASSEMBLY  
The carburetor is designed for use with LP gas in its  
vapor form. The following specifications apply:  
The carburetor is replaced as an entire assembly.  
Disassembly and reassembly is not required.  
Carburetor Inlet Diameter...........1.02inch (26mm)  
Carburetor Outlet Diameter........0.78 inch (20mm)  
Venturi Diameter ........................0.63 inch (16mm)  
Main Jet Diameter  
Number ..................................370  
Measured Size .......................0.145 inch (3.7mm)  
CARBURETION  
Refer to "Gaseous Carburetion" in Section 4.1 (Page  
4.1-3).  
CARBURETOR ADJUSTMENT  
The LP gas carburetor used on Impact Plus generator  
sets is equipped with a fixed jet and is non-adjustable.  
CARBURETOR REMOVAL  
Figure 1. LP Gas Carburetor  
Refer to Part 3, Section 3.4, Page 3.4-3 for carburetor  
removal procedures.  
Page 4.3-1  
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Section 4.3  
CARBURETOR  
Page 4.3-2  
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PART 5  
ENGINE OIL &  
COOLING SYSTEM  
SECTION  
5.1  
TITLE  
ENGINE OIL SYSTEM  
5.2  
ENGINE COOLING SYSTEM  
COMPUTER  
CONTROLLED  
VARIABLE  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Section 5.1  
ENGINE OIL SYSTEM  
INSPECTION:  
INTRODUCTION TO OIL SYSTEM  
To gain access to the screen, remove the oil filter  
support and its gasket. Pull the screen off its tubular  
protrusion. Clean the screen in solvent, then inspect  
for damage. Replace the screen if necessary.  
The engine oil system serves to (a) reduce friction  
between parts, (b) cool the engine, and (c) establish a  
slightly negative pressure in the crankcase to prevent  
oil leakage. Major components that will be discussed  
in this section include the following:  
OIL PUMP  
Oil Pickup Screen.  
Oil Pump.  
DESCRIPTION:  
Crankshaft Oil Seals.  
Pressure Relief Valve.  
Breather Assembly.  
Oil Sump.  
The oil pump is of the trochoid type. Its inner rotor  
rotates on a shaft provided in the camshaft bore of  
the oil sump. The outer rotor is installed over two  
drive pins on the end of the camshaft and is driven by  
camshaft rotation.  
Oil Filter Support Assembly.  
OIL FLOW  
See Figure 1. The oil pump draws oil from the oil  
sump through an oil pickup screen and delivers it to  
the areas requiring lubrication as follows:  
1. Through a cored channel in the oil sump to the crankcase jour-  
nal at one end of the crankshaft.  
2. Through the hollow camshaft to the camshaft bearing.  
3. Through a cored passage in the crankcase to the crankshaft  
journal.  
4. Through the crankshaft to the crankpin and connecting rod  
bearing.  
Figure 2. Oil Pump  
INSPECTION:  
See Figure 3. Inspect the inner and outer rotors of the  
pump for damage and wear. Use a feeler gauge to  
check tip clearance of the rotor (measured on the  
shaft in the oil sump). Check the bore inner diameter  
and the thickness of the inner rotor. If wear limits are  
exceeded, replace the appropriate part(s).  
PUMP TIP CLEARANCE  
(MEASURED ON SHAFT IN OIL SUMP)  
DESIGN CLEARANCE: 0.0000-0.0010 inch  
(0.000-0.025mm)  
WEAR LIMIT: 0.004 inch (0.105mm) Maximum  
INNER PUMP ROTOR BORE  
DESIGN BORE: 0.354-0.355 inch (9.000-9.019mm)  
WEAR LIMIT: 0.357 inch (9.034mm) Maximum  
Figure 1. Oil System Diagram  
INNER ROTOR THICKNESS  
DESIGN THICKNESS: 0.312-0.315 inch (7.95-8.00mm)  
WEAR LIMIT: 0.311 inch (7.90mm) Minimum  
OIL PICKUP SCREEN  
Replace any part that is damaged or worn excessive-  
ly. The shaft on which the inner rotor rotates is NOT  
replaceable (oil sump must be replaced).  
DESCRIPTION:  
The oil pickup screen consists of a cylindrical screen  
which is open at one end only. The screen's open end  
fits over a tubular protrusion in the oil sump, just  
behind the oil filter support. Also see "Oil Filter  
Support Assembly".  
Page 5.1-1  
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Section 5.1  
ENGINE OIL SYSTEM  
OIL PUMP (CONTINUED)  
PRESSURE RELIEF VALVE  
INSPECTION (CONT'D):  
DESCRIPTION:  
Inspect the outer drive pins on the camshaft. Look for  
breakage, bending, other damage. These are roll pins  
which can be removed and replaced.  
A ball type pressure relief valve is located in a bore of  
the crankcase. The ball and spring are retained in the  
crankcase bore by a spring retainer.  
The Relief Valve serves to limit oil pressure to a maxi-  
mum value. The ball will remain against its seat as  
long as oil pressure in the crankcase ail passage is  
below approximately 30 psi (29 kg/cm ). Should oil  
pressure increase above that value, the ball will be  
forced off its seat to relieve excess pressure into the  
crankcase.  
1. SCREW  
2. RETAINER  
3. SPRING  
4. BALL  
4
3
Figure 3. Oil Pump Check Points  
2
1
CRANKSHAFT OIL SEALS  
An oil seal is provided in the crankcase and in the oil  
sump, to prevent leakage past the crankshaft jour-  
nals. See Figure 4.  
A defective or leaking seal can be replaced. If the  
crankshaft has been removed from the engine, old  
seals can be removed by tapping out with a screw-  
driver or punching them out from inside. Oil seal  
pullers are available commercially, for seal removal  
with the crankshaft installed.  
Figure 5. Oil Pressure Relief Valve  
INSPECTION:  
Remove the 8mm screw that retains the spring  
RETAINER to the crankcase interior. Remove the  
RETAINER, SPRING and BALL. Clean all parts in  
solvent.  
Inspect the BALL and RETAINER for damage, exces-  
sive wear. Replace any damaged or worn compo-  
nents. Inspect the SPRING and replace if damaged  
or worn.  
Always use a seal protector when installing the crank-  
shaft into its crankcase bore and when installing the  
oil sump over the crankshaft.  
Apply a known test load to the SPRING, sufficient to  
compress the spring to a length of 1.03 inch  
(26.3mm). The amount of the test load at the stated  
spring length should be as follows:  
FORCE REQUIRED TO COMPRESS  
RELIEF VALVE SPRING TO 1.03 INCH (26.3mm)  
0.86-0.95 pounds (0.43-0.39 kg)  
If the test load at the stated length is not within limits,  
replace the SPRING.  
BREATHER ASSEMBLY  
DESCRIPTION:  
A crankcase breather is located in the crankcase  
assembly.  
Figure 4. Crankshaft Oil Seals  
Page 5.1-2  
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Section 5.1  
ENGINE OIL SYSTEM  
The breather serves to maintain a partial vacuum in  
the engine crankcase, to prevent oil from being forced  
past oil seals, gaskets or rings.  
INSPECTION:  
Clean the oil sump and blow dry with compressed air.  
Use compressed air to blow out all oil passages.  
Inspect the sump for cracks, damage, etc. Check the  
following bores in the oil sump for wear:  
See Figure 6. A reed type breather valve permits  
excess pressure to be vented out of the crankcase  
and to atmosphere through a breather tube. A  
breather retainer limits the movement of the breather  
valve. Two small oil return holes in the breather cup  
allow condensed oil vapors to drain back to the  
crankcase. A "steel wool" type breather separator  
separates the breather cup from the breather cover  
and breather tube opening.  
CRANKSHAFT BEARING BORE DIAMETER  
GV-220 ENGINE  
DESIGN DIAMETER: 1.104-1.105 inch (28.040-28.065mm)  
WEAR LIMIT: 1.106 inch (28.092mm) Maximum  
CAMSHAFT BEARING BORE DIAMETER  
GV-220 ENGINE  
DESIGN DIAMETER: 1.299-1.300 inch (33.00-33.03mm)  
WEAR LIMIT: 1.302 inch (33.06mm) Maximum  
OIL PUMP INNER ROTOR SHAFT DIAMETER  
GV-220 ENGINE  
DESIGN DIAMETER: 0.353-0.354 inch (8.969-8.987mm)  
WEAR LIMIT: 0.352 inch (8.949mm) Minimum  
OIL FILTER SUPPORT  
An oil filter support and its gasket are retained to the  
oil sump by four (4) M6-1.00 bolt.  
A threaded bore is provided in the support for a low  
oil pressure switch. This switch will protect the engine  
against damaging low oil pressure by shutting the  
engine down automatically if oil pressure should drop  
below a pre-set low limit.  
A high oil temperature switch is retained to the sup-  
port by two (2) M5 screws and lockwashers. This  
thermal sensor will protect the engine against damag-  
ing high temperature conditions through automatic  
shutdown.  
Figure 6. Breather Assembly  
INSPECTION:  
Remove the breather hose. Inspect it for cracks, dam-  
age, hardening. Replace, if necessary.  
Clean the breather cover and breather cup in com-  
mercial solvent. Check that the two small drain holes  
in the breather cup are open; open with a length of  
wire, if necessary.  
Inspect the rivets that retain the reed type breather  
valve, make sure they are tight. Also check that the  
valve seats flat on the breather cup around the entire  
surface of the valve.  
OIL SUMP  
DESCRIPTION:  
The die cast aluminum oil sump is retained to the  
crankcase with six (6) flanged head bolts. Install a  
new gasket between the oil sump and crankcase  
each time the oil sump is removed.  
Figure 7. Oil Filter Support  
Bores are provided in the oil sump for (a) oil pump  
rotors and camshaft, (b) crankshaft, (c) governor gear  
assembly, (d) oil pickup. Cored oil passages are pro-  
vided from the pickup to the pump and from the pump  
to the crankshaft bore.  
Page 5.1-3  
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Section 5.1  
ENGINE OIL SYSTEM  
Page 5.1-4  
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Section 5.2  
ENGINE COOLING SYSTEM  
It is absolutely essential that an adequate flow of air  
for cooling, ventilating and engine combustion be sup-  
plied to the generator set. Without sufficient air flow,  
the engine-generator quickly overheats. Such over-  
heating can cause serious operating difficulties and  
may also cause fire and personal injury. The installer  
must make sure that sufficient air is available to the  
generator for cooling, ventilating and combustion. The  
installer must also provide for a path for exhausting  
the cooling air to the exterior of a compartment, if so  
equipped.  
NOTE: Screening, louvers, or expanded metal that  
cover air openings restrict air flow that you must  
compensate for by making the actual air opening  
proportionately larger. See “Compensating for  
Restrictions.”  
For conventional compartment mounted units, the air  
inlet is generally provided in the compartment door.  
DANGER: Never use discharged cooling air  
for heating or permit such air to enter the  
vehicle interior. This air contains deadly car-  
bon monoxide gas and other poisonous,  
flammable or explosive gases.  
10 SQUARE INCHES  
(OPTIONAL OPENINGS)  
40 SQUARE  
INCHES  
(MINIMUM  
OPENING)  
GENERATOR AIR FLOW  
Engine operation drives cooling fans for the 2-stage  
cooling air system. A pressure fan draws cooling air  
into the top of generator and into the side of the con-  
trol panel (Figure 1). This air flow cools the engine-  
generator and electronic components. The second  
part of cooling system, a suction fan, draws air that is  
heated from a hot engine into a collector pan at the  
base of the unit. This heated air (although cooler than  
exhaust muffler) is directed across the muffler to cool  
it. The heated air flow is then deflected out the bottom  
toward the ground.  
Figure 2 Air Inlet in Compartment Door  
IMPORTANT: IF YOU PLAN TO INSTALL THE  
GENERATOR IN A COMPARTMENT, BE SURE  
TO LEAVE AT LEAST ONE INCH (2” recom-  
mended) OF CLEARANCE BETWEEN THE GEN-  
ERATOR AND COMPARTMENT WALLS AND  
CEILING. INCLUDE 26 GAUGE GALVANIZED  
STEEL LINING AND SOUND INSULATION WHEN  
YOU MEASURE FOR THIS 1 INCH (2” recom-  
mended) CLEARANCE.  
When the unit is installed on a suspended mounting  
system, one of several different methods of supplying  
air flow may be used as follows:  
Provide a door in the vehicle skirt having an air inlet  
opening (Figure 3, next page).  
Using ductwork (Figure 4 on next page). The installer  
must be sure air is available to the top of the generator  
since air inlets are located at the top.  
By providing an opening in the vehicle skirt and space  
above the generator for cooling air flow (Figure 5 on next  
page). Recommended clearance above the top of the  
generator is at least 2 inches.  
Figure 1 Air Flow Through Engine-Generator  
COOLING AIR INLET OPENINGS  
Ideally, you should provide three air inlet openings,  
whether the generator is housed in a conventional  
compartment or not. Two of the openings should be  
10 square inches and located as shown in Figure 2.  
The third opening should provide for a minimum of 40  
square inches unrestricted and be located lower on  
the compartment door.  
Page 5.2-1  
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Section 5.2  
ENGINE COOLING SYSTEM  
COMPENSATING FOR RESTRICTIONS  
Such materials as screening, louvers, or expanded  
metal can restrict the free flow of air. Compensate for  
this restriction by making the actual air opening pro-  
portionately larger.  
Some materials may offer only a 60 percent free air  
inlet area.Other more efficient materials may provide  
up to a 90 percent free air inlet area. The percentage  
of free air inlet opening is usually available from the  
material supplier or manufacturer.  
TO DETERMINE THE ACTUAL AIR INLET OPEN-  
ING SIZE REQUIRED, DIVIDE 40 SQUARE INCHES  
BY THE PERCENTAGE OF FREE AIR INLET AREA  
FOR THE MATERIAL YOU WILL USE.  
For example: If you plan to use screening with an  
80% free air inlet area, divide 40 by 0.8, which results  
in 50 square inches. Minimum actual size of air inlet  
opening in this case is 50 square inches. An opening  
that measures 4 inches wide by 12-1/2 inches long  
provides the required air flow (4 x 12.5 = 50 square  
inches).  
Figure 3 Suspended Mount Inlet Door  
INVERTER LOCATION  
In order for the inverter to work effectively, it should  
be located in a dry, well ventilated area.  
Approximately eight inches of space should be  
allowed at each end of the inverter for adequate ven-  
tilation.  
The sensing harnesses supplied with the inverter  
have a maximum length of 12 feet. If the cables are  
longer than needed, coil the excess near the inverter  
unit. If a greater length is needed, contact Generac.  
DO NOT ATTEMPT TO SHORTEN OR LENGTHEN  
THE SUPPLIED sensing harnesses. The DC power  
wires may be cut to the required length. Allow  
enough length to make connection. Coil excess  
inside J-Box.  
Figure 4. Ductwork  
CAUTION: Do not install the inverter in the  
engine compartment. Overheating may result.  
!
TESTING THE INSTALLATION  
Generac recommends testing the installation to be  
sure adequate cooling air flow is available to the  
unit before placing the unit into service. If the unit  
shows signs of overheating, you will need to  
enlarge the air openings. Never place a unit into  
service until absolutely certain that cooling and ven-  
tilation is adequate.  
Figure 5 Air Inlet in Vehicle Skirt  
IMPORTANT: YOU MUST TEST THE INSTALLA-  
TION ESPECIALLY IF YOU BRING IN AIR FROM  
BELOW THE GENERATOR SET.  
Page 5.2-2  
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PART 6  
ENGINE  
ELECTRICAL  
SYSTEM  
SECTION  
6.1  
TITLE  
ENGINE DC CONTROL SYSTEM  
6.2  
6.3  
6.4  
6.5  
6.6  
A6060 CIRCUIT BOARD  
ENGINE CRANKING SYSTEM  
ENGINE IGNITION SYSTEM  
ENGINE SHUTDOWN FEATURES  
OPTIONAL REMOTE PANEL  
COMPUTER  
CONTROLLED  
VARIABLE  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Section 6.1  
ENGINE DC CONTROL SYSTEM  
3. Engine Ignition System Components.  
GENERAL  
a.Ignition Module (IM).  
b.Ignition Sensor (IS).  
c. Ignition Coil (IC).  
d.Spark Plug (SP).  
The engine DC control system consists of all those  
electrical components required for cranking, starting  
and running the engine. These components include  
the following:  
1. Engine cranking system components  
a.A 12 VDC battery.  
4. Engine Protective Devices a. Low Oil Pressure Switch (LOP).  
b. High Oil Temperature Switch (HTO).  
b.A Start-Run-Stop Switch (SW1).  
c. A Starter Contactor (Starter Relay)-(SC).  
d.A Starter Motor (SM).  
5. An optional Remote Panel.  
2. Fuel system components..  
a.A Fuel Primer Switch (SW2).  
b.Fuel Pump (FP).  
(continued)  
Figure 1. Schematic- Engine DC Control System  
Page 6.1-1  
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Section 6.1  
ENGINE DC CONTROL SYSTEM  
NOTE: Also see Section 3.5, "AUTOMATIC  
CHOKE" and Section 6.2, "A6060 CIRCUIT  
BOARD".  
HOW IT WORKS  
ENGINE NOT RUNNING:  
RUNNING:  
1. Battery output (12VDC) is available to the contacts of a starter  
contactor (SC). However, the contacts are open.  
With fuel flow and ignition available, the engine starts  
and runs. The operator releases the Start-Run-Stop  
switch to its "RUN" position.  
2. Battery output is delivered to Terminals J2 - 5 of the A6060 cir-  
cuit board, via Wire 13, a 15 amp fuse, and Wire 15. Circuit  
board action holds this circuit open.  
1. The Wire 18 circuit is now open to ground. Circuit board action  
terminates the 12 VDC to the Starter Contactor (SC). The SC  
contacts open and cranking ends.  
3. Battery output is available to a Battery Charge Rectifier (BCR)  
via Wire 13, 15 amp Fuse (F1), Wire 15, a Resistor (R1) and  
Wire 15A.  
2. Choking action ends and the carburetor choke plate is posi-  
tioned by the Choke Heater (CH).  
3. Circuit board action continues to power the Wire 14 circuit- fuel  
flow and ignition continue.  
PRIMING:  
When the Primer Switch (SW2) is closed, battery volt-  
age is delivered to the engine Fuel Pump via Wire 13,  
7.5 Amp Fuse (F1), the Switch contacts (SW2) and  
Wire 14A. The Fuel Pump will operate to draw fuel  
from the tank and "prime" the fuel lines.  
NOTE: On units with LP gas fuel system, the Fuel  
Lockoff Solenoid (FS) will be turned on by closing  
the Primer Switch.  
NORMAL SHUTDOWN:  
When the Start-Run-Stop switch is held at "STOP",  
the Wire 18 circuit is connected to frame ground.  
A6060 circuit board action then terminates the DC  
flow to the Wire 14 circuit.  
1. Fuel Pump (FP) shuts down.  
CRANKING:  
2. Ignition terminates.  
When the Start-Run-Stop Switch is held at "START",  
the Wire 17 circuit from the A6060 circuit board is  
connected to frame ground. Circuit board action then  
initiates the following events:  
3. Engine shuts down.  
ENGINE PROTECTIVE DEVICE SHUTDOWN:  
Refer to "Oil Filter Support" on Page 5.1-3 and  
Section 6.5. The engine mounts a Low Oil Pressure  
Switch (LOP) and a High Oil Temperature Switch.  
1. Battery voltage is delivered to the Starter Contactor (SC) coil  
via Wire 56.  
a.The SC coil energizes and its contacts (SC)  
close after a few seconds.  
Section 6.5 also lists several other shutdown capabili-  
ties of the Impact Plus generator system.  
b.Closure of SC contacts deliver battery voltage to  
the Starter Motor (SM1) via Wire 16. The engine  
cranks.  
2. Battery voltage is delivered to the Wire 14 circuit.  
a.The Fuel Pump (FP) turns on.  
b.Power is available to the Ignition Module (IM)  
and ignition occurs.  
c. Power is available to the Inverter Fan for opera-  
tion.  
3. A6060 circuit board action operates the automatic choke  
through Wire 90.  
Page 6.1-2  
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Section 6.2  
A6060 CIRCUIT BOARD  
GENERAL  
The A6060 circuit board controls all phases of engine  
operation including cranking, starting, running and  
shutdown.  
The circuit board interconnects with other compo-  
nents of the engine electrical system.  
The board Is powered by fused 12 VDC battery out-  
put, available to the board via Wire 15.  
Figure 2. Receptacle J2  
PIN WIRE  
FUNCTION  
1
2
3
18  
85  
Not Used  
When grounded by Low Oil Pressure or High  
Oil Temperature Switch, the circuit board will  
shut down the engine  
4
5
17  
15  
When Wire 17 is connected to ground by  
holding Start-Run Stop Switch at START,  
cranking will occur.  
Figure 1. A6060 Circuit Board  
Fused battery voltage. The Wire 15 circuit is  
electrically hot at all times (provided the unit  
battery is connected).  
CIRCUIT BOARD CONNECTIONS  
RECEPTACLE J1:  
6
7
0
Common frame ground.  
The A6060 circuit board mounts an 8-pin receptacle  
J1. An 8-pin connector plug connects to the A6060.  
This harness then connects to a 9-pin connector plug  
on the outside panel of the control box. This becomes  
the 9-wire harness that connects to the inverter.  
Signals from the A6060 circuit board control the func-  
tions of the inverter.  
90  
Delivers 12 VDC to automatic choke solenoid  
coil while cranking only.  
8
9
56  
14  
Delivers 12 VDC to starter contactor while  
cranking only.  
Delivers 12 VDC (during cranking and run  
ning) to (a) Engine Fuel System, (b) Engine  
Ignition System and (c) Remote Panel Lamp  
if so equipped.  
RECEPTACLE J2:  
The A6060 circuit board mounts a 10-pin receptacle  
J2. A 10-pin connector plug connects to this recepta-  
cle to interconnect the board with other components  
and circuits.  
This 10-pin receptacle is shown in Figure 2, along  
with a chart that Identifies each pin, wire and function.  
Wire 14 connects to Terminal J2-9. This terminal and  
wire are electrically hot (12 volts DC) only when the  
engine is cranking or running. Battery voltage is deliv-  
ered to Terminal J2-9 when circuit board action ener-  
gizes a board-mounted run relay while cranking or  
running.  
Wire 14 DC output is delivered to (a) the engine fuel  
pump and (b) the engine ignition system. If an option-  
al remote panel Is used, Wire 14 DC output will turn  
on a "RUN" lamp on that panel.  
10  
Not Used  
NOTE 1: - See "SHUTDOWN FEATURES” In  
Section 6.5 (Page 6.5-1).  
RECEPTACLE J3:  
The A6060 circuit board mounts a 6-pin receptacle  
J3. A 6-pin connector plug connects to the A6060.  
This harness then connects to Stepper Motor. Signals  
from the A6060 circuit board control the Stepper  
Motor operation. Refer to page 3.6-1 for test proce-  
dures.  
(continued)  
Wire 15 connects to Terminal J2-5. This Is fused bat-  
tery voltage. The Wire 15 circuit is electrically hot at  
all times (provided the unit battery Is connected).  
Page 6.2-1  
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Section 6.2  
A6060 CIRCUIT BOARD  
CIRCUIT BOARD CONNECTIONS  
(CONTINUED)  
RECEPTACLE J4:  
The A6060 circuit board mounts a 3-pin receptacle  
J4. A 3-pin connector plug connects to the A6060.  
This harness then connects to Bridge Rectifier. DC  
Link Voltage is supplied to the circuit board for volt-  
age sensing.  
RECEPTACLE J5:  
The A6060 circuit board mounts a 2-pin receptacle  
J5. A 2-pin connector plug connects to the A6060.  
This harness then connects to TIM1/TIM2. The  
A6060 circuit board uses this signal for speed  
sensing.  
Page 6.2-2  
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Section 6.3  
ENGINE CRANKING SYSTEM  
INTRODUCTION  
BATTERY  
COMPONENTS:  
RECOMMENDED BATTERY:  
The engine cranking system is shown schematically  
in Figure 1, below. The system consists of the follow-  
ing components:  
The battery is generally supplied by the customer.  
Recommended is a battery that meets the following  
requirements:  
A 12 volts Battery.  
Use a 12 VDC automotive type storage battery.  
A Start-Run-Stop Switch (SW1).  
A Starter Contactor (SC).  
A Starter Motor (SM1).  
A6060 Circuit Board.  
For prevailing ambient temperatures above 32° F.  
(0° C.), use a battery rated at 70 amp-hours and  
capable of delivering 360 cold-cranking amperes.  
For prevailing ambient temperatures below 32° F.  
(0° C.), use a battery rated 95 amp-hours and capa-  
ble of delivering 450 cold-cranking amperes.  
Interconnecting wires.  
OPERATION:  
BATTERY CABLES:  
1. Holding the Start-Run-Stop switch (SW1) at "START" connects  
Wire 17 from the A6060 circuit board to frame ground.  
Battery cables should be as short as possible and of  
adequate diameter. Cables that are too long or too  
small in diameter can result in voltage drop. The volt-  
age drop between battery terminals and the connec-  
tion point at generator should not exceed 0.121 volts  
per 100 amperes of cranking current.  
The cables should be carefully selected based on (a)  
cable length and (b) prevailing ambient temperatures.  
Generally, the longer the cable and the colder the  
ambient temperature, the larger the required cable  
size. The following chart applies:  
a.A6060 circuit board action energizes a crank  
relay on the board after a three second delay.  
b.Closure of the crank relay's contacts delivers 12  
VDC to Wire 56 and to a Starter Contactor (SC).  
The Starter Contactor (SC) energizes and its  
contacts close.  
2. Closure of the the Starter Contractor (SC) contacts delivers  
battery voltage to the Starter Motor (SM1). The Motor ener-  
gizes and the engine is cranked.  
CABLE LENGTH  
Feet (Meters)  
CABLE SIZE  
0 to 10 (0 to 3)  
11 to 15 (3.4-4.5)  
16 to 20 (4.5 to 6)  
2*  
0
000  
* For warm weather use No. 2 cable up to 20 feet.  
BATTERY CABLE CONNECTIONS:  
1. Connect the cable from the large Starter Contactor (SC) lug to the  
battery post indicated by a POSITIVE, POS or (+).  
2. Connect the cable from its FRAME GROUND connection to the  
battery post indicated by a NEGATIVE, NEG or (-).  
Figure 1. Schematic - Cranking Circuit  
(continued)  
Page 6.3-1  
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Section 6.3  
ENGINE CRANKING SYSTEM  
1. Set the VOM to its "Rx1 " scale and zero the meter.  
BATTERY (CONTINUED)  
2. Connect the VOM test leads across the Wire 17 terminal and  
the center (Wire 0) terminals.  
TESTING A BATTERY:  
The best method of testing a battery is with an auto-  
motive type battery hydrometer. Some "Maintenance  
Free" batteries cannot be tested with a hydrometer.  
Most batteries can be tested for both STATE OF  
CHARGE and CONDITION as follows:  
a.Hold the switch at "START" and the VOM  
should indicate "continuity".  
b.Hold switch at "STOP" and meter should read  
"infinity".  
3. Now, connect the meter test leads across the center and Wire  
18 terminals.  
1. Test for State of Charge:  
a.Follow the hydrometer manufacturer's instruc-  
tions carefully. Test the specific gravity of the  
fluid in all battery cells.  
a.With switch at "START" VOM should indicate  
"infinity".  
b.With switch at "STOP", meter should read "con-  
tinuity".  
b.If the hydrometer does not have a "Percentage  
of Charge" scale, compare the readings  
obtained with the following:  
Replace the switch if it is defective.  
SPECIFIC GRAVITY  
PERCENTAGE OF CHARGE  
1.260  
1.230  
1.200  
1.170  
100%  
75%  
50%  
25%  
STARTER CONTACTOR  
WIRE AND CABLE CONNECTIONS:  
The red (positive) battery cable connects to one of  
the starter contactor's large terminal lugs. The unit's  
15 amp fuse also attaches to this lug, via Wire 13.  
The starter motor (SM1) cable (16) attaches to the  
second terminal lug.  
If the battery State of Charge is less than 100%, use  
an automotive type battery charger to recharge it to a  
100% State of Charge.  
Wire 56, from the A6060 circuit board, attaches to  
one of the small contactor terminals.  
2. Test for Condition:  
a.If the difference in specific gravity between the  
highest and lowest reading cell is greater than  
0.050 (50 points), the battery is nearing the end  
of its useful life and should be replaced.  
TESTING THE STARTER CONTACTOR:  
To test the installed Starter Contactor, proceed as fol-  
lows:  
b.However, if the highest reading cell is less than  
1.230, recharge the battery and repeat the test.  
1. Set a volt-ohm-milliammeter (VOM) to read battery voltage (12  
VDC).  
2. Connect the VOM test leads across the Wire 56 terminal of the  
Contactor and frame ground. The meter should indicate "zero"  
volts.  
START-RUN-STOP SWITCH (SW1)  
Wires 17 and 18 connect to the two outer terminals of the  
switch. Wire 0 (ground) connects to the switch center termi-  
nal. The switch can be tested using a volt-ohm-milliamme-  
ter (VOM) as follows:  
3. Hold the Start-Run-Stop switch at "START" and the VOM  
should read battery voltage and the Contactor should energize.  
After reading the voltage, release the switch. If battery voltage  
is NOT indicated, a problem exists elsewhere in the circuit.  
4. Connect the VOM test leads across the Wire 16 terminal lug  
and frame ground.  
a.Hold the Start-Run-Stop switch at "START". The  
Contactor should actuate and the meter should  
indicate battery voltage.  
b.If battery voltage is not indicated, replace the  
Starter Contactor.  
c. If battery voltage is indicated but engine does  
not crank, check the Starter Motor and its cable.  
Figure 2.  
Page 6.3-2  
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Section 6.3  
ENGINE CRANKING SYSTEM  
STARTER MOTOR  
DESCRIPTION:  
The Starter Motor is a 12 volts negative ground type.  
It is capable of operating on heavy duty battery input  
at temperatures as low as -30 F. without any signifi-  
cant change in performance. Its pinion is a 10-tooth  
type having a 20- pressure angle.  
TESTING:  
Connect the test leads of a VOM across the Starter  
Motor terminal and case. Hold the Start-Run-Stop  
switch at "START". The VOM should read battery  
voltage and the Starter Motor should turn.  
If VOM reads 12 volts DC and the Motor does not  
turn, the Motor is probably defective. Remove the  
Motor and test with a 12 volts DC power source.  
Figure 3. Starter Contactor  
Replace the Starter Motor if defective.  
Figure 4. Starter Motor  
Page 6.3-3  
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Section 6.3  
ENGINE CRANKING SYSTEM  
Page 6.3-4  
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Section 6.4  
ENGINE IGNITION SYSTEM  
As the generator's Permanent Magnet Rotor turns  
during operation, magnets on the Ignition Cage rotate  
past the Ignition Sensor to induce a timed low voltage  
pulse into the Sensor. This voltage pulse is delivered  
to an Ignition Module and serves as a timing pulse for  
the Module.  
INTRODUCTION  
The engine ignition system consists of the following  
major components:  
Ignition Cage Assembly.  
Ignition Sensor Assembly.  
Ignition Module (IM).  
Ignition Coil (IC).  
Spark Plug (SP1).  
IGNITION CAGE ASSEMBLY  
An IGNITION CAGE ASSEMBLY is factory installed  
onto the permanent magnet rotor hub. Two magnets  
are installed in the cage as shown in Figure 1 (50°  
apart), so that the north pole of one magnet faces  
away from the cage outer periphery and the north  
pole of the other magnet faces toward the cage outer  
periphery. A special fixture is used to install the cage  
onto the rotor hub so that the center line of the first  
magnet is 68° away from the Rotor Hub mounting  
hole as shown.  
NOTE: Placement of the magnets on the Rotor  
Hub at the exact position stated above results in  
an ignition timing of 29 ° BTDC.  
The Ignition Cage assembly cannot be replaced. The  
entire Rotor Hub must be replaced. Replacement  
Rotor Hubs will include a factory installed Ignition  
Cage assembly, and Magnetic Housing Assembly.  
Figure 2. Ignition Sensor  
See Figure 3. The Sensor circuit board mounts solid  
state components which are sensitive to magnetism.  
Magnets in the Ignition Cage rotate past the Sensor,  
causing the base of a transistor to be "pulsed". The  
transistor acts much like a "switch" or a set of "con-  
tact points". Pulsing the transistor base causes the  
"switch" to close and connect the "OUT" lead to the  
"GND" lead. This triggers the Ignition Module to deliv-  
er a primary ignition current to the Ignition Coil at  
timed intervals.  
NOTE: Also refer to "Permanent Magnet Rotor" in  
Section 1.2 (Page 1.2-1).  
Figure 3. Ignition Sensor Schematic  
Figure 1. Ignition Cage Assembly  
IGNITION MODULE  
While cranking and running, battery voltage is deliv-  
ered to the Ignition Module via Wire 14 from the  
A6060 circuit board. The Module will deliver this bat-  
tery voltage to the Ignition Coil based on the "timing"  
signal it receives from the Ignition Sensor.  
The Ignition Module is retained in the generator con-  
trol panel by two capscrews.  
IGNITION SENSOR  
The Ignition Sensor is retained to the AC generator's  
Stator Adapter by means of two M4-0.70 x 8mm  
screws and lockwashers. The Sensor housing houses  
a circuit board. The entire housing cavity is filled with  
potting material.  
Page 6.4-1  
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Section 6.4  
ENGINE IGNITION SYSTEM  
Clean the Spark Plug and reset its gap to 0.030 inch  
(0.76mm) every 100 hours of operation. Clean by  
scraping or wire brushing and washing with commer-  
cial solvent. DO NOT blast clean the spark plug.  
IGNITION MODULE (CONTINUED)  
SUMMARY OF OPERATION  
See Figure 6. As the generator's permanent magnet  
rotor turns, magnets in the Rotor hub's Ignition Cage  
rotate past an Ignition Sensor at fixed intervals.  
Battery voltage is delivered to an Ignition Module dur-  
ing cranking and running, via Wire 14. From the  
Ignition Module, battery voltage is also delivered to  
the Ignition Sensor via the RED (+) lead. The Ignition  
Sensor acts as a "trigger" mechanism, causing the  
Ignition Module to deliver its output to the Ignition Coil  
at timed intervals. Current flows through the primary  
coil of the Ignition Coil and then collapses to induce a  
high voltage into the Ignition Coil's secondary coil.  
This high voltage (about 25,000 volts) is delivered to  
the park Plug to fire the spark plug gap.  
Figure 4. Ignition Module  
IGNITION COIL  
Primary ignition voltage (12 VDC) is delivered from  
the Ignition Module to the Ignition Coil. The Coil  
boosts the voltage and delivers the high voltage to  
the engine Spark Plug.  
Components encapsulated in the Ignition Module pro-  
vide an automatic spark advance. At cranking  
speeds, ignition will occur at about 15'-18' BTDC. At  
higher speeds, ignition can occur up to 29° BTDC.  
Figure 5. Ignition Coil  
Figure 7. Ignition System Diagram  
SPARK PLUG  
The Spark Plug on the GV-220 engine is a Champion  
RC12YC (or equivalent).  
IGNITION TIMING  
Ignition timing is fixed and non-adjustable.  
TESTING THE SYSTEM  
GENERAL:  
Solid state components inside the Ignition Sensor,  
Ignition Module and Ignition Coil are not accessible and  
cannot be serviced. If any of these components is  
defective, the entire component must be replaced. The  
system does not include an armature and there is no air  
gap to adjust, or breaker points to adjust or replace.  
Figure 6. Setting Spark Plug Gap  
Page 6.4-2  
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Section 6.4  
ENGINE IGNITION SYSTEM  
TESTING FOR SPARK:  
CHECK POWER SUPPLY:  
To test the ignition system, a suitable spark tester  
may be used. Such spark testers are commercially  
available. Test the system as follows:  
When the engine is being cranked, battery voltage  
should be available from the A6060 circuit board to a  
4-terminal connector via Wire 14. From the 4-terminal  
connector, battery voltage should be available to the  
Ignition Module via Wire 14 (RED wire). And battery  
voltage should be available from the Ignition Module  
to the Ignition Sensor via a RED wire. If this 12 VDC  
power supply is not available, the ignition system will  
not function. To check the power supply, proceed as  
follows using a volt-ohm-milliammeter (VOM):  
Warning! Do NOT use a screwdriver to test for  
spark. Personal injury or damage to equip-  
ment may result.  
!
1. Disconnect the high tension lead from the spark plug.  
2. Attach the spark plug high tension lead to the spark tester ter-  
minal.  
1. Gain access to the control panel interior.  
2. In the panel, locate the 3-pin connector that interconnects the  
Ignition Module and the Ignition Sensor.  
3. Connect the spark tester clamp to the engine cylinder head.  
4. Crank the engine rapidly. Engine must be turning at 350 rpm or  
more. If spark jumps the tester gap, you may assume the igni-  
tion system is operating satisfactorily.  
3. Press down on the connector lock tang and disconnect the two  
connector halves.  
NOTE: A single large black lead carries the three  
leads from the Ignition Sensor to the 3 pin MALE  
connector. The three leads from the Ignition  
Module (brown, green and red) attach to the 3 pin  
FEMALE connector.  
If sparking across the tester gap does NOT occur, go  
to CHECK POWER SUPPLY.”  
4. Set the VOM to a scale that will allow battery voltage to be  
read (about 12 volts DC).  
5. Connect the meter test leads across the center FEMALE pin  
(RED wire) and frame ground.  
6. Hold the Start-Run-Stop switch at "START". The meter should  
read battery voltage.  
Figure 8. Testing for Spark  
CHECKING ENGINE MISS:  
To determine if an engine miss is ignition related,  
connect the spark tester in series with the spark  
plug's high tension lead and the spark plug. Then,  
start the engine. If spark jumps the tester gap at regu-  
lar intervals but the engine miss continues, the prob-  
lem is in the spark plug or in the fuel system.  
Figure 10.  
If battery voltage is NOT indicated, go to Step 7. If  
battery voltage IS indicated, go to "CHECK IGNITION  
SENSOR."  
7. Now locate the 4-terminal connector in the panel.  
Connect the VOM test leads across the terminal and  
frame ground. Crank the engine and the VOM should  
read battery voltage.  
a.If battery voltage is indicated now but was NOT  
indicated in Step 6, test Wire 14 (RED) between  
the 4-terminal connector and the Ignition Module.  
If wire is bad, repair or replace as necessary.  
(continued)  
Figure 9. Checking Engine Miss  
Page 6.4-3  
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Section 6.4  
ENGINE IGNITION SYSTEM  
b.Connect the VOM test leads across the two  
male pins of the 2-pin connector. Primary coil  
resistance should be about 0.5 to 1.5 ohms.  
TESTING THE SYSTEM (CONTINUED)  
CHECK POWER SUPPLY (CONTD):  
3. To read SECONDARY coil resistance:  
b.If battery voltage is NOT indicated in Step 7,  
test Wire 14 between the 4-terminal connector  
and the A6060 circuit board. Repair or replace  
as necessary.  
a.Set the VOM to its "Rx10,000" or "Rx1 K" scale  
and zero the meter.  
b.Unplug the high tension lead from the Spark  
Plug.  
CHECK IGNITION SENSOR:  
c. Connect one VOM test lead to the white wire  
connector pin.  
1. In the 3-pin connector plug half from the Ignition Module, locate  
FEMALE Pin 1 to which the BROWN wire connects.  
d.Connect the other VOM test lead into the Spark  
Plug lead rubber boot so it contacts the lead's  
metal terminal end. The VOM should read  
approximately 16,000-17,000 ohms (16.0-17.0  
k-Ohms).  
2. Connect a jumper wire from FEMALE Pin 1 (BROWN wire) to  
frame ground.  
3. Connect the Spark Plug high tension lead to a spark tester  
(Figure 8) and the spark tester clamp to ground.  
Replace the Ignition Coil if defective. If the Ignition  
Coil tested good, go to "TESTING IGNITION MOD-  
ULE".  
4. Crank the engine and observe the spark tester for sparking.  
Note: Only one spark should be observed upon  
initial cranking.  
TESTING IGNITION MODULE:  
If a problem was indicated under "TESTING FOR  
SPARK", you should have completed the tests under  
"CHECK POWER SUPPLY", under "CHECK  
IGNITION SENSOR" and under "TESTING IGNITION  
COIL". If these components tested good, replace the  
Ignition Module.  
Figure 12. Testing Ignition Sensor  
If sparking occurs with the BROWN wire grounded  
but did NOT occur under "TESTING FOR SPARK",  
the Ignition Sensor is probably defective and should  
be replaced.  
NOTE: The Ignition Sensor is mounted to the gen-  
erator's Stator Adapter. To replace the Sensor,  
disassembly of the generator and removal of the  
Stator will be necessary.  
Figure 13. Testing Ignition Coil  
If sparking does NOT occur with the BROWN wire  
grounded and did NOT occur under "TESTING FOR  
SPARK", either the Ignition Module or the Ignition Coil  
is defective. Go to "TESTING IGNITION COIL".  
TESTING IGNITION COIL:  
The Ignition Coil is housed in the generator control  
panel. To test the coil, proceed as follows:  
1. Unplug the two halves of the 2-pin connector plug from the  
Ignition Coil. The red and white wires are the primary coil  
leads.  
Figure 14. Testing Ignition Module  
2. To read PRIMARY coil resistance:  
a.Set a volt-ohm-milliammeter (VOM) to its "Rx1 "  
scale and zero the meter.  
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Section 6.5  
SHUTDOWN FEATURES  
GENERAL  
The engine mounts an Oil Pressure Switch (LOP) and  
an Oil Temperature Switch (HTO). These two switch-  
es, in conjunction with the A6060 circuit board, pro-  
tect the engine against (a) low oil pressure and (b)  
high oil temperature.  
The engine protective circuit Is shown in Figure 1.  
OIL PRESSURE SWITCH  
DESCRIPTION:  
The Oil Pressure Switch has normally-closed contacts  
which are held open by engine oil pressure during  
cranking and running. Should oil pressure drop below  
approximately 5 psi, the switch contacts will close to  
complete the Wire 85 circuit to ground. A6060 circuit  
board action will then de-energize the Wire 14 circuit  
and the engine will shut down.  
Figure 2. Engine Protective Devices  
The A6060 circuit board provides a time delay to  
allow oil pressure to build during startup, to prevent  
premature shutdown.  
TESTING THE SWITCH:  
Use a volt-ohm-milliammeter (VOM) to test the oil  
pressure switch. Connect the VOM test leads across  
the switch terminal and the switch body. With the  
engine shut down, the meter should read "continuity"  
(a very small resistance is acceptable). With engine  
running, the meter should read "infinity".  
OIL TEMPERATURE SWITCH  
DESCRIPTION:  
This thermostatic switch has normally-open contacts.  
Should engine oil temperature exceed a preset safe  
value (about 293° F.), the switch contacts will close.  
On closure of the Switch contacts, the Wire 85 circuit  
will be connected to frame ground. Engine shutdown  
will then occur.  
Figure 3. Testing the Oil Temperature Switch  
TESTING:  
See Figure 3. Remove the switch and place its sens-  
ing tip into oil. Place a thermometer Into the oil.  
Connect the test leads of a VOM across the switch  
terminals. The meter should read "Infinity". Heat the  
oil. When oil temperature reaches approximately  
287°-296° F. (142°-147° C.), the meter should read  
"continuity" (a small resistance is acceptable).  
(continued)  
Figure 1. Engine Protective Circuit  
Page 6.5-1  
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Section 6.5  
SHUTDOWN FEATURES  
ADDITIONAL SHUTDOWN FEATURES  
The A6060 Circuit Board also incorporates the follow-  
ing protective shutdown features:  
LOSS OF 12-PIN CABLE SIGNALS TO INVERTER:  
The generator will shutdown if the 12-pin connector is  
disconnected from the inverter when CB1 is turned to  
ON.  
This shutdown will occur after approximately 5-7  
seconds.  
LOSS OF TIM1/TIM2 INPUT TO A6060 CIRCUIT BOARD:  
If Timing Winding input is lost, the generator will  
immediately shutdown.  
LOSS OF PS1/PS2 TO INVERTER:  
A loss of voltage from PS1/PS2 windings to the  
inverter will simulate a 12-pin signal failure and cause  
a shutdown when CB1 is turned to ON.  
This shutdown will occur after approximately 5-7  
seconds.  
OVERSPEED OF ENGINE:  
Overspeed of the engine will result in an immediate  
shutdown. This automatic generator shutdown will  
occur at engine speed above 4200 rpm.  
SHORT CIRCUIT PROTECTION:  
If the inverter senses a short circuit on the AC output  
side it will automatically shut the generator down.  
INVERTER OVERHEAT CONDITION:  
If the inverter overheats, AC output will be shut off.  
The engine will continue to run for approximately two  
minutes and then shut down. The maximum ambient  
temperature rating is 120°F.  
DC LINK VOLTAGE GREATER THAN 600 VDC:  
If DC link voltage exceeds 600 VDC, the inverter will  
shut off AC power output.  
DC LINK UNDER-VOLTAGE SHUTDOWN:  
If DC link voltage drops below 100 VDC, the inverter  
will shut off AC power output.  
Page 6.5-2  
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Section 6.6  
OPTIONAL REMOTE PANEL  
The remote panels mount a rocker type start/stop  
switch, a Generator Runadvisory lamp and an  
hourmeter. The hourmeter should be used in conjunc-  
tion with the maintenance operations found in Part I of  
this manual.  
Model 004057 includes the remote panel and a 10  
foot long, 4 wire harness.  
GENERAL  
An optional remote-mounted Start-Stop panel is avail-  
able. This panel will permit the generator to be started  
and stopped from some convenient remote location in  
the recreational vehicle.  
REMOTE PLUG-IN RECEPTACLE  
Model 004184 includes the remote panel and a 30  
foot long, 4 wire harness.  
A plug-in receptacle (Figure 2.24) is provided on the  
generator set, near the DC power wires. Use this  
receptacle to connect an optional remote-mounted  
start/stop panel to the generator. Installation of such a  
panel will permit you to start and stop the generator  
engine from any convenient location inside the vehi-  
cle.  
WIRE #18  
(STOP)  
WIRE #14  
(ENGINE RUN  
SIGNAL)  
WIRE #17  
(CRANK)  
WIRE #10  
(GROUND)  
Figure 1. Remote Panel Plug-In Receptacle  
REMOTE START/STOP PANEL  
A remote mounted Start/Stop panel (Figure 2.25) is  
available that allows the user to start and stop the  
generator engine conveniently from inside the vehicle.  
The remote panel includes a Start/Stop switch,  
hourmeter, generator run lamp and a wire harness.  
Figure 2. Optional Remote Panel  
(Models 004057 and 004184)  
Page 6.6-1  
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Section 6.6  
OPTIONAL REMOTE PANEL  
Page 6.6-2  
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PART 7  
TROUBLE-  
SHOOTING  
SECTION  
7.1  
TITLE  
GENERATOR & SPEED CONTROL  
7.2  
ENGINE DC CONTROL SYSTEM/  
AC TROUBLESHOOTING  
COMPUTER  
CONTROLLED  
VARIABLE  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Section 7.1  
GENERATOR & SPEED CONTROL SYSTEM  
TROUBLESHOOTING REFERENCE CHART  
PROBLEM  
POSSIBLE CAUSE  
REMEDY  
PAGE  
3.4-3  
1. Engine starts, accelerates,  
shuts down at 4500 rpm  
a. Carburetor linkage sticking with  
throttle stuck open.  
a. Repair sticking throttle  
b. Stepper Motor failed or seized.  
c. Stepper Motor wire connections  
broken or disconnected.  
b. Replace Stepper Motor.  
c. Reconnect or repair.  
3.6-1  
3.6-1  
d. Stepper Motor not properly connected.  
d. Reconnect wires.  
3.6-1  
3.4-3  
2. Overvoltage condition and  
speed control system cannot  
reduce output voltage.  
a. Carburetor linkage sticking with  
throttle stuck partly open.  
a. Repair sticking throttle.  
b. Stepper Motor failed or seized.  
c. Connection to Stepper Motor is  
broken/disconnected with throttle open.  
d. Stepper Motor not properly connected.  
b. Replace Stepper Motor.  
c. Repair or replace connections.  
3.6-1  
3.6-1  
d. Reconnect Stepper Motor wires.  
a. Repair sticking throttle.  
3.6-1  
3.4-3  
3. Engine speed is maintained  
and no-load voltage is good.  
However, when load is applied  
output voltage drops.  
a. Carburetor linkage sticking with  
throttle partly open.  
b. Stepper Motor failed or seized.  
c. Connection to Stepper Motor  
Motor broken or disconnected.  
d. Stepper Motor not properly  
connected.  
b. Replace Stepper Motor.  
c. Repair or replace connections.  
3.6-1  
3.6-1  
d. Reconnect Stepper Motor.  
3.6-1  
4. Engine does not accelerate  
when load is applied.  
a. Carburetor linkage sticking  
with throttle stuck closed.  
b. Stepper Motor failed or seized.  
c. Stepper Motor not properly  
connected.  
a. Repair sticking throttle.  
3.4-3  
b. Replace Stepper Motor.  
c. Reconnect Stepper Motor.  
3.6-1  
3.6-1  
5. Engine speed and AC output  
voltage erratic under constant  
load. AC output does not turn  
off intermittently.  
a. Stepper Motor failure.  
b. Connection to Stepper Motor  
broken or disconnected.  
c. Stepper Motor not properly  
connected  
a. Replace Stepper Motor.  
b. Repair or replace connections.  
3.6-1  
3.6-1  
c. Reconnect Stepper Motor.  
3.6-1  
6. Engine starts but Stepper  
Motor does not move. Shut down  
occurs after several seconds.  
a. Stator Timing winding is open.  
a. Repair/replace bad wire(s)  
TIM1/TIM2 or replace Stator.  
b. Replace Stator.  
1.5-2  
1.5-2  
b. Timing winding in Stator shorted  
to ground.  
Page 7.1-1  
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Section 7.1  
GENERATOR & SPEED CONTROL SYSTEM  
Page 7.1-2  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
INTRODUCTION  
This Section contains troubleshooting information pertaining to the engine DC control system. The section is  
divided into two parts, i.e., troubleshooting flow charts and diagnostic test procedures.  
Use the flow charts and the test procedures in conjunction with one another. The first step in troubleshooting is to  
identify the problem. After identifying the problem, go to the flow chart that best describes it. Perform each test in  
the flow chart and follow the flow chart arrows and instructions. If you need instructions for any test, refer to the  
applicable diagnostic test procedure.  
Problem solving on the computer controlled generator is somewhat more complex than problem solving on con-  
ventional units. The A6060 circuit board, in addition to its voltage and frequency control functions, has engine  
shutdown capability. See AUTOMATIC SHUTDOWNSon Page 1.2-5. The A6060 circuit board, part of the  
engines DC control system, also has engine shutdown capability.  
Fortunately, neither the generator proper nor the engine DC control system has a large number of parts. When a  
problem is encountered, its solution can usually be found after only a few tests.  
PROBLEM 1- PRIMING FUNCTION DOES NOT WORK  
Page 7.2-1  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 2 - ENGINE WILL NOT CRANK  
PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START  
Page 7.2-2  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START (CONTINUED)  
Page 7.2-3  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 4 - ENGINE STARTS HARD AND RUNS ROUGH  
Page 7.2-4  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 5 - ENGINE STARTS THEN SHUTS DOWN AFTER A FEW SECONDS  
12  
SHUTS DOWN  
TEST 31  
TEST INVERTER  
(Pg. 7.2-18)  
FAIL  
REPLACE INVERTER  
Page 7.2-5  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 6 - GENERATOR DOESNT PULL FULL LOAD  
PROBLEM 7 - GENERATOR CIRCUIT BREAKER TRIPS / NO AC VOLTAGE  
Page 7.2-6  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 8 - ENGINE SHUTS DOWN UNDER LOAD  
PROBLEM 9 - GENERATOR LOSES AC POWER THEN SHUTS DOWN  
12  
Page 7.2-7  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 10 - NO AC OUTPUT  
12-WIRE  
12  
12  
Page 7.2-8  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
PROBLEM 10 - NO AC OUTPUT (CONTINUED)  
Page 7.2-9  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
TEST 1- CHECK 7.5 AMP FUSE  
DISCUSSION:  
The panel-mounted 7.5 amp fuse is connected in  
series with the 12 VDC power supply to the engine  
DC control system. A blown fuse will prevent engine  
priming, cranking and running.  
TEST PROCEDURE:  
Push in on fuse holder cap and turn it counterclock-  
wise to remove cap and fuse. Check the fuse visually.  
If the fuse metal element has melted open, replace  
the fuse.  
Figure 2. Primer Switch  
If the visual check is uncertain, use a VOM to check  
fuse.  
TEST 3- CHECK POWER TO FUEL PUMP  
RESULTS:  
1. If fuse is good  
DISCUSSION:  
When the rocker type primer switch is held at ON",  
position, fused battery voltage is delivered to the elec-  
tric fuel pump. The pump should then turn on and  
prime the carburetor.  
During cranking and startup, the A6060 circuit board  
will deliver battery voltage to the Wire 14 circuit and  
to the Fuel Pump. The pump should turn on and run.  
a.And if priming function does not work, go to  
Test 2.  
b.And if engine will not crank, go to Step 4. 2. If  
fuse is bad, replace it.  
Figure 1. 7.5 Amp Fuse  
TEST 2- CHECK POWER TO PRIMER SWITCH  
Figure 3. Fuel Pump  
TEST PROCEDURE:  
Locate the red Wire 14A that connects to the fuel  
pump. A wiring connector connects the wires near the  
pump. Separate the wire, then check for DC power as  
follows:  
DISCUSSION:  
This is a check of the PRIMER SWITCH on the panel.  
When the switch is actuated to its "PRIME" position,  
fused battery voltage is delivered directly to the elec-  
tric fuel pump on units with gasoline fuel system. On  
units with gaseous fuel system, battery voltage is  
delivered to the fuel lockoff solenoid.  
1. Set VOM to read battery voltage.  
TEST PROCEDURE:  
2. Connect the VOM test leads across the Wire 14A from the  
Primer Switch and frame ground.  
Set a VOM to read battery voltage (12 VDC). Connect  
the meter test leads across the Wire 15 terminal of  
the Primer Switch and frame ground. The meter  
should read battery voltage.  
3. Hold the Primer Switch at °ON" (Prime). Meter should read bat-  
tery voltage.  
RESULTS:  
4. Hold the panel Start-Run-Stop switch at "START". The meter  
should read battery voltage.  
1. If battery voltage is indicated, go to Test 3.  
2. If battery voltage is NOT indicated, go to Test 4.  
Page 7.2-10  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
RESULTS:  
TEST 6- TEST PRIMER SWITCH  
1. If unit is being tested because the priming function doesn't work:  
DISCUSSION:  
a.!f battery voltage is good but the pump doesn't  
work, go to Test 5.  
See Figure 2 on facing page. When this rocker type  
switch is held at "PRIME" position, fused battery volt-  
age is delivered to the Fuel Pump to prime the carbu-  
retor.  
b.!f battery voltage is NOT indicated, go to Test 6.  
2. If engine cranks but will not start:  
With the switch set to "OFF", battery voltage is deliv-  
ered to the Fuel Pump from the A6060 circuit board  
during cranking and running (via Wire 14).  
a.!f battery voltage is good but the pump doesn't  
work, go to Test 5.  
b.If DC power to pump is good and pump works,  
go to Test 22.  
TEST PROCEDURE:  
1. Disconnect Wires 15,14 and 14A from the switch terminal to  
prevent interaction.  
TEST 4- CHECK BATTERY/BATTERY CIRCUIT  
2. Set a VOM to its "Rx1" scale and zero the meter.  
DISCUSSION:  
3. Connect the VOM test leads across the Wire 15 terminal and  
the Wire 14A terminal. The meter should read "infinity". Set the  
switch to "ON" or "PRIME" and the meter should indicate "con-  
tinuity.  
The battery circuit includes the red battery cable that  
extends from the units 12 volt battery to the Starter  
Contactor. The circuit also includes Wire 13 (RED)  
from the Starter Contactor to the 15 amp Fuse. It  
includes one Wire 15 from the Fuse to the Primer  
Switch and a Wire 15 from the Fuse to the A6060 cir-  
cuit board.  
4. Connect the VOM test leads across the Wires 14 and 14A ter-  
minals. The meter should read "continuity". Set the switch to  
"ON" or "PRIME" and the VOM should read "infinity".  
TEST PROCEDURE:  
Inspect the battery terminals and cables carefully.  
Clean cables and cable connections if necessary.  
Replace any bad cable(s), including the battery nega-  
tive cable, if necessary.  
RESULTS:  
1. Replace switch if it fails the test. 2. If the switch is good, go to  
Test 7.  
Check Wires 13 and 15 for an open or shorted condition.  
Repair, reconnect or replace bad wire(s) as necessary.  
Use a battery hydrometer to test the battery for "state  
of charge" and for "condition". Follow the hydrometer  
manufacturer's instructions carefully. If the hydrome-  
ter used does not have a "percentage of charge"  
scale, use the following as a reference:  
TEST 7- CHECK WIRE 14A TO FUEL PUMP  
DISCUSSION:  
If no power was available to the Fuel Pump in Test 3,  
either the Primer Switch is defective or Wire 14A is  
open.  
SPECIFIC GRAVITY  
PERCENTAGE OF CHARGE  
1.260  
1.230  
1.200  
1.170  
100%  
75%  
50%  
25%  
TEST PROCEDURE:  
Inspect Wire 14A between the fuel pump and primer  
switch for proper connections. Check for open condi-  
tion with a VOM.  
RESULTS:  
RESULTS:  
Repair, reconnect or replace Wire 14A as necessary.  
1. Repair, reconnect or replace any open or shorted wi re(s).  
2. If necessary, recharge the battery to a 100% state of charge.  
Disconnect the battery cables before recharging the battery.  
TEST 8- CHECK POWER SUPPLY TO  
STARTER MOTOR  
3. If (after recharging) the difference in specific gravity between  
the highest and lowest reading cells is greater than 0.050 (50  
points) the battery is nearing the end of its useful life and  
should be replaced.  
DISCUSSION:  
When the Start-Run-Stop switch is set to "START",  
Wire 17 is connected to ground. A6060 circuit board  
action then delivers a DC voltage to the Starter  
Contactor coil and the Contactor's normally-open con-  
tacts close. On closure of the contacts, battery power  
is delivered directly to the Starter Motor to crank the  
engine.  
TEST 5- TEST FUEL PUMP  
Refer to Page 3.3-1.  
Page 7.2-11  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
This test will determine if battery voltage is available  
to the Starter Motor for cranking the engine.  
3. Set the Start-Run-Stop switch to "START". The meter should  
indicate battery voltage.  
TEST PROCEDURE:  
RESULTS:  
1. Set a VOM to read battery voltage (12 VDC).  
1. No power to Wire 56 terminal, go to Test 10.  
2. Connect the meter test leads across the starter terminal and  
frame ground.  
2. If power to Starter Contactor is good, go to Test 11.  
3. Hold the Start-Run-Stop switch at "START". The VOM should  
read battery voltage and the engine should crank.  
RESULTS:  
1. If power supply is good and engine cranks, stop tests.  
2. If power supply is good but engine does NOT crank, replace  
the Starter.  
3. If power supply is bad, go on to Test 9.  
4. If voltage drops during cranking (i.e. from 12 VDC to 9.5 VDC  
or lower), then check battery condition and cable sizes per the  
installation manual. Verify that proper grounding of the genera-  
tor exists.  
Figure 5. Starter Contactor  
TEST 10- CHECK A6060 CIRCUIT BOARD  
POWER SUPPLY  
DISCUSSION:  
Fused battery voltage is delivered to the A6060 circuit  
board via Wire 15. If this power (12 VDC) is not avail-  
able to the board, cranking and startup will not be  
possible.  
This test will determine if battery voltage is available  
to the circuit board for its operation.  
TEST PROCEDURE:  
Set a VOM to read battery voltage (12 VDC).  
Figure 4. Starter Motor  
Connect one VOM test lead to the Wire 15 terminal  
J2-5 on the A6060 circuit board. Connect the other  
test lead to frame ground. The meter should indicate  
battery voltage.  
TEST 9- CHECK WIRE 56 POWER TO  
STARTER CONTACTOR  
RESULTS:  
DISCUSSION:  
1. If battery voltage is NOT indicated, check Wire 15 between the  
7.5 amp fuse and the A6060 circuit board. Repair, reconnect or  
replace the wire as needed.  
When the Start-Run-Stop switch is set to "START",  
the A6060 circuit board must react by delivering bat-  
tery voltage to the Starter Contactor coil, via Wire 56.  
Without this battery voltage, the Contactor will not  
energize and battery output will not be delivered to  
the Starter Motor. The engine will not crank.  
2. If Battery Voltage was indicated, test for proper ground from  
the A6060 circuit board. Set a VOM to read Resistance.  
Measure from terminal J2-6 to the generator frame ground. A  
Continuityreading should exist. If open or high resistance is  
measured, repair wires or ground connections.  
TEST PROCEDURE:  
1. Set a VOM to read battery voltage (12 VDC).  
2. Connect the meter test leads across the Wire 56 starter con-  
tactor terminal and frame ground.  
3. If 12 VDC was indicated, go to Test 12.  
Page 7.2-12  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
2. If engine stops when Wire 18 is grounded but will not shut  
down with Start-Stop switch, replace the Switch.  
TEST 11- TEST STARTER CONTACTOR  
DISCUSSION:  
3. If engine will not crank when Wire 17 is grounded, replace the  
A6060 circuit board.  
See "Starter Contactor" on Page 6.3-2. Replace  
Starter Contactor if bad.  
4. If engine will not stop when Wire 18 is grounded, replace the  
A6060 circuit board.  
TEST 12- TEST START-STOP SWITCH  
TEST 13- CHECK FUEL SUPPLY  
DISCUSSION:  
Engine cranking and startup are initiated when the  
Start-Stop switch is held at "START" to ground Wire  
17.  
Engine shutdown is normally initiated when the Start-  
Stop switch is set to "STOP" to ground Wire 18.  
DISCUSSION:  
If the engine cranks but won't start, don't overlook the  
obvious. The engine won't start without fuel.  
TEST PROCEDURE:  
Check fuel level.  
A defective switch can prevent normal startup or nor-  
mal shutdown.  
RESULTS:  
1. If fuel level is low, replenish fuel supply.  
2. If fuel quantity is good, go to Test 14.  
TEST 14- CHECK FUEL FILTER  
Refer to Section 3.3.  
TEST 15- CHECK IGNITION SPARK  
Refer to Section 6.4, "ENGINE IGNITION SYSTEM".  
TEST 16- CHECK SPARK PLUG  
DISCUSSION:  
Figure 7. Start-Stop Switch  
TEST PROCEDURE:  
A badly fouled spark plug can prevent the engine  
from starting. A defective spark plug may allow the  
engine to be started, but rough operation or an  
"engine miss" may be observed.  
A commercially available spark tester can be used to  
check for ignition spark. When the spark tester is con-  
nected in series with the spark plug and its high ten-  
sion lead, the cause of an engine miss can be nar-  
rowed down to either (a) the ignition system, or (b)  
the spark plug or fuel system. Use of the spark tester  
is discussed in Test 16.  
1. Carefully inspect Wire 0 (Ground) between the Start-Stop  
switch and the ground terminal. Repair, reconnect or replace  
the wire if necessary.  
2. Disconnect Wire 17 from its terminal on the Start-Stop switch.  
Connect Wire 17 to a clean frame ground. The engine should  
crank.  
3. Start the engine, using the Start-Stop switch or by grounding  
Wire 17.  
TEST PROCEDURE:  
Remove the spark plug.  
Clean by scraping or wire brushing and by using a  
commercial solvent. DO NOT BLAST CLEAN THE  
PLUG. Set spark plug gap to 0.030 inch (0.76mm).  
Replace spark plug if badly fouled, if ceramic is  
cracked, or if damaged.  
4. Stop the engine by holding the Start-Stop switch at "STOP". If  
engine will not shut down with switch at "STOP", ground Wire  
18 to stop engine.  
RESULTS:  
1. If engine cranks when Wire 17 is grounded, but won't crank  
with Start-Stop switch, replace the Start-Stop switch.  
Page 7.2-13  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
2. Connect the VOM test leads across the 4-tab connector and  
frame ground.  
3. Hold the engine Start-Stop switch at "START".  
The meter should read battery voltage.  
RESULTS:  
1. If DC voltage is NOT indicated, go to Test 21.  
2. If DC voltage is good, go on to Test 18.  
Figure 8. Checking Spark Plug Gap  
TEST 18- CHECK IGNITION SENSOR  
RESULTS:  
1. Clean and regap or replace spark plug as necessary.  
DISCUSSION:  
2. If spark plug is good but engine will not start, go to Test 3.  
Refer to Section 6.4, "ENGINE IGNITION SYSTEM".  
3. If spark plug is good but engine misses or runs rough,. go to  
Test 23.  
TEST PROCEDURE:  
See Section 6.4.  
RESULTS:  
TEST 17- CHECK IGNITION POWER SUPPLY  
1. Replace Sensor, if bad.  
2. If Sensor checks good, go to Test 19.  
DISCUSSION:  
During startup, the A6060 circuit board delivers DC  
power to the Ignition Module via Wire 14. If the  
engine cranks but won't start, one possible cause is  
loss of this power supply.  
The DC power from the A6060 Circuit Board is deliv-  
ered to a 4-tab terminal connector. From that connec-  
tor, it is routed to the Ignition Module.  
TEST 19- CHECK IGNITION COIL  
DISCUSSION:  
See Section 6.4, "ENGINE IGNITION SYSTEM".  
TEST PROCEDURE:  
See Section 6.4.  
These components are all housed in the control panel.  
RESULTS:  
1. Replace Ignition Coil if bad.  
2. If coil is good, go to Test 20.  
TEST 20- TEST IGNITION MODULE  
DISCUSSION:  
See Section 6.4, "ENGINE IGNITION SYSTEM".  
TEST PROCEDURE:  
Refer to Section 6.4.  
RESULTS:  
Replace Ignition Module if bad.  
Figure 9. Ignition Module & 4-Tab Connector  
TEST PROCEDURE:  
TEST 21 - CHECK A6060 CIRCUIT BOARD  
OUTPUT TO WIRE 14  
In the control panel, inspect the Wire 14 connections  
at the 4-tab connector. Check Wire 14. Check the  
power supply as follows:  
DISCUSSION:  
If the engine cranks when the Start-Stop switch is set  
to "START", battery voltage must be available to the  
A6060 circuit board.  
1. Set a VOM to read battery voltage.  
Page 7.2-14  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
If the engine cranks but won't start, it is possible that  
TEST 23- CHECK CARBURETION  
a failure in the circuit board has occurred and DC  
power is not being delivered to the Wire 14 circuit.  
DISCUSSION:  
This test will determine if circuit board action will deliver  
battery voltage to the necessary engine components.  
If the engine won't start or if it starts hard and runs  
rough, one possible cause of the problem is carburetion.  
PROCEDURE:  
PROCEDURE:  
Set a VOM to read battery voltage. Connect the meter  
test leads across Pin J2-9 of the A6060 circuit board  
and Pin J2-6 of the circuit board connector (to which  
common ground Wire 0 connects). Crank the engine  
and the meter should read battery voltage.  
Before making a carburetion check, make sure the  
fuel tank has an ample supply of clean fresh gasoline  
(gasoline fuel systems) or gaseous fuel. The installer  
may have installed a gas or gasoline shutoff valve in  
the fuel supply system. Make sure all shutoff valves  
are open.  
RESULTS:  
Make sure the automatic choke is working properly  
and that the choke closes completely.  
If the engine will not start, remove the spark plug and  
inspect it. If the plug is WET, look for the following:  
Overchoking.  
Water in fuel.  
1. If DC voltage was NOT indicated in Test 17, but IS indicated  
now, repair, reconnect or replace Wire 14 between board and  
Ignition Module.  
2. If no DC voltage in Test 3 but good voltage now, replace Wire  
14 between board and fuel pump.  
Excessively rich fuel mixture.  
Intake valve stuck open.  
3. If there is no DC output from the circuit board to Wire 14,  
replace the A6060 circuit board.  
If the spark plug is DRY, look for the following:  
Carburetor gasket(s) leaking.  
Fuel line plugged or shutoff valve not opening.  
Intake valve stuck closed.  
Inoperative fuel pump.  
Clogged fuel filter.  
RESULTS:  
Adjust or repair carburetor or fuel system as necessary.  
TEST 24- CHECK ENGINE  
DISCUSSION:  
Figure 10. Receptacle J2  
An engine that will not start or one that starts hard  
and runs rough may be caused by a failure in the  
engine's mechanical system.  
TEST 22-TEST AUTOMATIC CHOKE  
PROCEDURE:  
DISCUSSION:  
Refer to Section 3.5, "AUTOMATIC CHOKE".  
The first step in checking for an engine problem is to  
perform a compression check. To check engine com-  
pression, proceed as follows:  
TEST PROCEDURE:  
See Section 3.5.  
1. Remove the spark plug.  
2. Insert an automotive type compression gauge into the spark  
plug hole.  
RESULTS:  
1. Adjust or repair choke system as necessary.  
3. Crank the engine until there is no further in-crease in pressure.  
The highest reading obtained is the engine's compression  
pressure.  
2. !f choke is good, go to Test 23.  
(continued)  
Page 7.2-15  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
ENGINE COMPRESSION PRESSURE  
TEST 27- TEST OIL TEMPERATURE SWITCH  
NOMINAL PRESSURE: 60 psi  
MINIMUM ALLOWABLE: 55 psi  
DISCUSSION:  
NOTE: Full compression pressure cannot be  
obtained at cranking speeds, due to the action of  
a compression release mechanism.  
See Section 6.5, "ENGINE SHUTDOWN FEATURES.”  
TEST PROCEDURE:  
See Section 6.5.  
RESULTS:  
If compression is poor, look for one or more of the fol-  
lowing possible causes:  
RESULTS:  
NOTE: The generator will shutdown if the 12-pin  
connector is disconnected and the circuit breaker  
is turned on. In order to perform the running  
diagnostic tests, you must jump pin #10 to pin  
#11. This will enable the unit to continue to run  
with the circuit breaker turned to the ONposi-  
tion (See Figure 10 on page 7.2-17).  
1. Loose cylinder head bolts.  
2. Failed cylinder head gasket.  
3. Burned valves or valve seals.  
4. Insufficient valve clearance.  
5. Warped cylinder head.  
TEST 28 - DC LINK VOLTAGE TEST  
6. Warped valve stem.  
1. Disconnect the 12-pin connector from the inverter. Disconnect  
the Red-Black-Blue-Green DC Link wires from the inverter.  
7. Worn or broken piston ring(s).  
8. Worn or damaged cylinder bore.  
9. Broken connecting rod.  
Note: Cap the DC Link wires with a wire nut for  
safety.  
2. On units with A6060 circuit board revision Dor higher soft-  
ware, jump pin #10 to pin #11 on the 12-pin cable previously  
removed from the inverter. The 12 position cable should be  
connected to the 12-pin socket on the generator control panel.  
This will enable the generator to run with CB1 turned ON.  
TEST 26- TEST OIL PRESSURE SWITCH  
DISCUSSION:  
See Section 6.5, "ENGINE SHUTDOWN FEATURES.”  
3. Turn CB1 to ON position. Start generator. The engine should  
run at approximately 3300 rpm.  
TEST PROCEDURE:  
See Section 6.5.  
4. Set VOM to DC. Measure DC Link voltage between the Red  
and Blue wires, place Red test lead to red wire and Black test  
lead to the Blue wire. DC voltage should be approximately 375  
VDC. Measure DC link voltage between the Red wire and  
Black wire, place Red test lead to Red wire and Black test lead  
to Black wire, DC voltage should read +175 VDC. Measure  
DC link voltage between the Blue wire and the Black wire,  
place Red test lead to Blue wire and Black test lead to Black  
wire. DC voltage should read 175 VDC.  
If necessary, connect an external oil pressure gauge  
to the oil pressure switch port.  
RESULTS:  
1. Replace oil pressure switch if it is defective or repair Wire 85  
circuit as necessary.  
2. If oil pressure is actually low as indicated by the external  
gauge, see Section 5.1, "ENGINE OIL SYSTEM".  
3. If oil pressure is good and oil pressure switch is good, go to  
Test 27.  
Page 7.2-16  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
2. On units with A6060 circuit board revision Dor higher soft-  
TEST 29 - 12 POSITION HARNESS  
CONTINUITY TEST  
ware, jump pin #10 to pin #11 on the 12 position cable previ-  
ously removed from the inverter. The 12 position cable should  
be connected to the 12 position socket on the generator control  
panel. This will enable the generator to run with CB1 turned  
ON.  
1) Set VOM to measure Resistance.  
2. Measure from pin location #1 on one end of the 12 position  
harness to pin location #1 on the opposite end of the harness.  
A reading of Continuityshould be measured. Repeat proce-  
dure for each pin position on the 12-wire harness. If an open  
condition is detected, replace the defective harness as neces-  
sary.  
3. Turn CB1 to ON position. Start generator. The engine should  
run at approximately 3300rpm.  
4. Set a DVOM to DC volts. Measure from the free end of the 12  
position harness according to the chart below. Connect the  
negative and positive test leads as indicated in the chart.  
3. If needed, check for continuity on the A6060 circuit board wire  
harness in the control panel. This connection is at location J1  
on the circuit board. Follow the same procedure as steps 1 and  
2 above.  
(Note: Fluke 87 true RMS meter used in test.)  
5. Set a DVOM to AC volts. Measure the the free end of the 9-  
Wire harness according to the chart below. Connect the nega-  
tive and positive test leads as indicated in the chart.  
TEST 30  
-
12 POSITION HARNESS SIGNALS TEST  
ASSUMPTION:  
Engine runs  
Inverter not connected  
TEST PROCEDURE:  
1. Disconnect the 12-wire cable from the inverter. Disconnect the  
Red-Black-Blue-Green DC Link wires from the inverter.  
Note: Cap the DC Link wires with a wire nut for  
safety.  
Figure 10 Free End of 12 Position Harness  
Test With DVOM  
Set At DC Volts  
Connect negative lead to: Connect positive lead to: Reading should be:  
Inverter Signals Ground  
Inverter Signal  
Pin 9 (0 v)  
Pin 2 (En/Com)  
Pin 2 (En/Com)  
Pin 9 (0 v)  
Pin 2 (En/Com)  
Pin 1 (PWM1)  
Pin 3 (PWM2)  
Pin 10 (TEMP)  
Pin 4 (Wire #14)  
< 0.10 vdc  
2.5 v 0.15 vdc  
2.5 v 0.15 vdc  
5.0 v 0.1 vdc  
12 v 1.0 vdc  
Inverter Signal  
Temperature Voltage  
Inverter Fan Voltage  
Pin 9 (0 v)  
Shield Wire  
Test for Ground  
Pin 12 (SHIELD)  
Pin 4 (Wire #14)  
12 v 1.0 vdc  
Test With DVOM  
Set At AC Volts  
Connect negative lead to: Connect positive lead to: Reading should be:  
Inverter Signal  
Inverter Signal  
Pin 2 (En/Com)  
Pin 2 (En/Com)  
Pin 1 (PWM1)  
Pin 3 (PWM2)  
2.5 v 2.0 vac*  
2.5 v 2.0 vac*  
* Tolerance is large because readings will vary,  
depending on type of meter used.  
Page 7.2-17  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
TEST 31 - STATIC TESTS ON INVERTER  
STATOR TESTS  
ASSUMPTION:  
• Inverter not connected to generator.  
TEST 32 - POWER SUPPLY WINDING TEST  
• Inverter has been disconnected for at least 5 min-  
utes from running genset to allow capacitors to dis-  
charge.  
1. Disconnect the 12 position cable from the inverter.  
2. Start the unit with CB1 in the OFF position.  
3. Set a VOM to measure AC. Measure voltage across Pin #6  
and Pin #7. The power supply voltage should be approximately  
25-30 VAC at approximately 2700 rpm.  
TEST PROCEDURE:  
1. Set a DVOM to DIODE RANGE. Measure the 12 position con-  
nector on the inverter according to the chart below. Connect  
the negative and positive test leads as indicated in the chart.  
4. Turn CB1 to the ON position.  
2. Set a DVOM to RESISTANCE RANGE. Measure the 12 position  
connector on the inverter according to the chart below. Connect  
the negative and positive test leads as indicated in the chart.  
5. Voltage across the floating power supply should be approxi-  
mately 30 to 34VAC at approximately 3400rpm.  
6. If results are lower, there is a possible stator problem. Proceed  
to Test 34.  
TEST 33 - TIMING WINDING TEST  
1. Disconnect the timing winding from receptacle J5 on the A6060  
circuit board (orange and grey wires).  
2. Disconnect the 12 position harness from the inverter.  
3. Two jumper wires with alligator clips are required.  
4. Attach a jumper from Wire #15 (located at the fuse holder) to  
Wire #14 (located at the four tab terminal block in the control  
panel). This will enable fuel and ignition functions.  
Figure 11. 12 Position Connector on Inverter  
1. Test With DVOM  
Set At Diode Range  
Connect negative lead to: Connect positive lead to: Reading should be:  
Signal Circuit  
Pin 2 (En/Com)  
Pin 2 (En/Com)  
Pin 1 (PWM1)  
Pin 3 (PWM2)  
1.25 to 1.5 v  
1.25 to 1.5 v  
Signal Circuit  
2. Test With DVOM  
Set At Resistance Range Connect negative lead to: Connect positive lead to: Reading should be:  
Temperature Circuit  
Pin 9 (0 V)  
Pin 10 (TEMP)  
*10 kOhm @ 25°C  
500 Ohms  
Sense Circuit  
Pin 9 (0 V)  
Pin 11 (SENSE)  
20 kOhm 200 Ohm  
*NTC thermistor; if inverter is hot, resistance may be several kOhm lower. If inverter is cold, resistance  
may be several kOhm higher  
3. Test With DVOM  
Set At AC Volts  
Connect negative lead to: Connect positive lead to: Reading should be:  
Pin 9 (0 V) Pin 4 (Wire #14) See Note  
Fan Test  
NOTE: Use a ballpoint pen or small screwdriver to spin the blades of the inverter-cooling fan.  
Momentarily, observe a reading of 10 - 30 mV.  
Page 7.2-18  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
5. Momentarily jump Wire #15 (located at the fuse holder) to Wire  
4. Instal paper clips in connector to use as a test point.  
5. Set a VOM to the DIODE test range.  
#56 (located at the Starter Contactor). This will initiate cranking  
of the engine. The generator will start, but the throttle will need  
to be controlled manually. Hold the throttle at about a half load  
setting.  
6. Attach the negative test lead of the VOM to the Red Wire and  
the positive test lead to the Blue Wire.  
7. The voltage measured across the Bridge Rectifier should be  
approximately 1.000 VDC. Any voltage reading higher or lower  
indicates a defective diode assembly. Disassemble the Bridge  
Rectifier and test each diode individually.  
6. Set a VOM to measure AC. Measure the AC voltage at the tim-  
ing winding connector (orange and grey wires). The voltage  
should be between 15 and 20 VAC.  
7. If results are lower, there is a possible stator problem. Proceed  
to Test 34.  
TEST 36 - AC POWER WINDING TEST  
AC1/AC2/SL1/SL2  
TEST 34 -STATOR RESISTANCE VALUES  
1. Turn CB1 to the OFF position.  
2. Set a VOM to measure AC Volts.  
Refer to Part 1, Section 1.4 and 1.5 for test procedures.  
AC1 to AC2 ................................................. 0.414 to 0.465 ohms  
SL1 to SL2................................................... 0.414 to 0.465 ohms  
#55 to #66 ................................................... 0.095 to .108 ohms  
#55 to #77 ................................................... 0.095 to 0.108 ohms  
TIM1 to TIM2............................................... 0.102 to 0.116 ohms  
PS1 to PS2.................................................. 0.206 to 0.227 ohms  
3. Connect one test lead to the bottom Grey wire (AC1) on CB1.  
Connect the other test lead to the Yellow wire (AC2) located on  
the Bridge Rectifier.  
4. Start the generator.  
5. The measured AC voltage reading should be approximately  
187 VAC.  
6. Connect one test lead to the bottom Orange Wire (SL1) on  
CB1. Connect the other test lead to the Brown wire (SL2) locat-  
ed on the Bridge Rectifier.  
TEST 35 - BRIDGE RECTIFIER TEST  
1. Disconnect the Red-Black-Blue-Green DC Link wires from  
either the connection in the control panel or at the inverter.  
Isolate the DC Link wires.  
7. Start the generator.  
8. The measured AC voltage reading should be approximately  
187 VAC.  
2. Turn CB1 to the OFF position.  
9. If a lower voltage is measured, proceed to Test 34.  
3. Disconnect the 3-pin connector at J4 on the A6060 circuit  
board.  
Page 7.2-19  
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Section 7.2  
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING  
Page 7.2-20  
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PAGE  
8-1  
TITLE  
General Specifications  
PART 8  
SPECIFICATIONS  
AND CHARTS  
8-1  
Nominal Resistances of  
Generator Windings  
8-2  
8-3  
Electrical Schematic  
Wiring Diagram  
8-4 to 8-8 Engine Specifications  
COMPUTER  
CONTROLLED  
VARIABLE  
8-9  
Engine Torque Specifications  
8-10  
Major Features and Dimensions  
SPEED RV  
GENERATORS  
Series Impact 36 Plus  
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NOTES  
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Part 8  
SPECIFICATIONS & CHARTS  
TYPE  
Impact 36 G  
Impact 36 LP  
MODEL  
0940  
0941  
TYPE OF ROTOR  
RATED WATTS  
RATED VOLTS  
PHASE  
Permanent Magnet Type  
Permanent Magnet Type  
3600  
115  
3400  
115  
1-Phase  
30.0  
1-Phase  
28.3  
RATED MAXIMUM  
LOAD AMPERES  
RATED FREQUENCY  
60 Hz  
60 Hz  
OPERATING SPEED  
(See NOTE 1)  
Variable  
Variable  
ENGINE MODEL  
TYPE OF ENGINE  
FUEL SYSTEM  
COOLING SYSTEM  
OIL SYSTEM  
GV-220  
GV-220  
Vertical Shaft  
Gasoline  
Vertical Shaft  
LP Gas  
Air-Cooled  
Pressure  
Air-Cooled  
Pressure  
OIL PUMP  
Trochoid Type  
Trochoid Type  
AIR CLEANER  
Paper element  
Paper element  
w/foam pre-cleaner  
w/foam pre-cleaner  
STARTER  
12 VDC electric  
Solid State  
12 VDC electric  
Solid State  
IGNITION SYSTEM  
SPARK PLUG  
Champion RC12YC  
(or equivalent)  
Champion RC12YC  
(or equivalent)  
SPARK PLUG GAP  
0.030 inch  
(0.76mm)  
0.030 inch  
(0.76mm)  
NOTE 1: Engine speed will vary between approximately 2400-4000 rpm, depending on the load and load voltage.  
NOMINAL RESISTANCES OF GENERATOR WINDINGS  
Stator Power Phase Windings  
Stator Timing Winding  
Lead AC1 .................................0.414 to 0.465 ohm  
Lead AC2 .................................0.414 to 0.465 ohm  
Lead SL1..................................0.414 to 0.465 ohm  
Lead SL2..................................0.414 to 0.465 ohm  
Lead TIM1 (orange)  
to TIM2 (grey)...........................0.102 to 0.116 ohm  
Stator Battery Charge Windings  
Lead 55 to 77 ...........................0.095 to 0.108 ohm  
Lead 55 to 66 ...........................0.095 to 0.108 ohm  
Stator Power Phase Winding  
Lead PS1 .................................0.206 to 0.227 ohm  
ENGINE SPEEDS AND VOLTAGE SPECIFICATIONS  
Listed below are normal running voltages, load voltages, engine speeds and frequency ranges.  
LOAD %  
VOLTAGE (VAC)  
121-112  
FREQUENCY (Hz)  
61-59  
ENGINE SPEED (rpm)  
2800-2400  
0
50  
100  
120-109  
61-59  
3500-3000  
120-109  
61-59  
4000-3500  
Page 8-1  
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Part 8  
SPECIFICATIONS & CHARTS  
ELECTRICAL SCHEMATIC (DRAWING NO. 0D4947-B)  
1 OF 2  
CUSTOMER SUPPLIED  
BATTERY  
SC  
16  
SM  
13  
13  
15  
15  
F1  
SW2  
FP  
14A  
HM  
0
REMOTE  
PANEL  
(LP ONLY)  
90  
CONNECTOR  
14  
CC  
0
0
1
2
3
4
1
2
3
4
0
17  
17  
14  
18  
14  
CH  
14  
START  
17  
SW1  
14  
14  
STOP  
18  
18  
15  
90  
14  
0
0
IM  
IS  
0
18 14 17  
15  
HTO  
0
85  
IC  
R1  
LOP  
85  
SP1  
15A  
BCR  
90  
77  
66  
14  
77  
66  
BATTERY CHARGE WINDING  
0
STOP  
START  
55  
18  
SL1  
SL2  
L1  
POWER  
WINDING  
HM  
AC2  
TIMING  
POWER SUPPLY  
85  
17  
TIM1  
AC1  
TIM2  
PS1  
PS2  
CB1  
REMOTEE PANEELL  
(OPTIONAL)  
GRN  
2
RED  
1
2
4
1
2
4
1
1
2
4
BLU  
BR1  
3
BR2  
BR3  
BR4  
AC  
1
2
3
3
4
3
J4  
RED  
3
0
BLK  
15  
14  
BLU  
INV  
J3  
1
2
1
2
T1  
J1  
3
4
3
4
M
J2  
DC  
TB  
GRN  
J2  
90  
7
6
1
2
3
4
5
6
1 2  
J5  
J3  
SHIELD  
8
12  
11  
10  
9
SENSE  
TEMP  
FAN-  
7
6
5
4
3
2
1
J1  
FAN+  
PWM2  
RTN  
4
3
2
1
PWM1  
1
PCB1  
18  
0
2
3
4
5
85  
J2  
17  
56  
WHITE  
T2  
6
7
SC  
GRN  
J4  
8
9
14  
BLK  
T1  
1
2
3
10  
RED  
BLU  
120V  
CUSTOMER AC CONNECTION  
Page 8-2  
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Part 8  
SPECIFICATIONS & CHARTS  
WIRING DIAGRAM (DRAWING NO. 0D4947-B)  
2 OF 2  
CUSTOMER  
SUPPLIED  
REMOTE  
PANEL  
4
3
2
1
13  
J3  
CONNECTOR  
12V  
BATTERY  
IS  
0
RED  
0
BLK  
85  
16  
16  
15  
RED  
BLK  
VIO  
SM  
HTO  
GRD  
SHLD  
0
13  
85  
LOP  
F1  
15  
15  
BLK  
0
GRN  
13  
RED  
RED  
IC  
SP1  
17 ORG  
SW2  
SC  
ORG  
VIO  
15  
14A  
BRN  
RED  
RED  
WHT  
18 VIO  
56  
GENERATOR CONTROL  
J2  
SW1  
10  
9
14  
RED  
14  
17  
RED  
RED  
BLK  
RED  
56  
15  
DK BLU  
0
8
7
GRN  
R1  
90  
6
5
4
IM  
0
RED  
RED  
RED  
85  
18  
3
2
1
90  
CH  
GRN  
VIO  
14 14  
RED  
GRD  
2
14  
BLK  
CC  
0
14  
55  
BLK  
BLK  
15A  
PCB1  
RED  
TC  
J2  
J1  
1
1
2
3
PWM1  
BLK  
2
3
RTN  
PWM2  
WHT  
RED  
4
4
5
6
FAN+  
FAN-  
GRN  
RED/BLK  
9
TEMP  
SENSE  
SHIELD  
BLU  
ORG  
SHLD  
10  
11  
12  
7
7
8
J5  
J4  
2
J3  
1
2
1
3
1
2
3
4
5
6
6
BLK RED  
FP  
BLK  
RED  
-
+
HM  
DC  
J1  
J3  
1
(LP ONLY)  
FAN  
+DC BUS  
RED  
1
BLUE  
2
2
BLK  
BLU  
RTN  
3
1
BLK RED  
BR1  
3
3
4
-DC BUS  
4
3
2
1
4
EARTH  
GRN  
CB1A  
BR2  
ORG  
J8-1  
J8-2  
TB  
4
3
2
1
GRN  
J2  
J11-7  
J11-4  
J11-3  
J11-2  
J11-1  
J11-6  
J11-5  
1
2
PWM1  
RTN  
PWM2  
FAN+  
BR3  
BR4  
4
3
2
1
3
M
GRY  
4
CB1B  
10A  
9
FAN-  
4
2
10  
11  
12  
7
TEMP  
RED  
INVERTER  
CONTROL  
SENSE  
SHIELD  
PS2  
6
PS1  
BLK  
YEL  
55  
J9  
ORG RED  
BRN  
BCR  
J10  
GRY  
J4  
66  
77  
1
2
BRN  
BLK  
BLK  
3
IND  
CHASSIS AC  
INVERTER  
NEUTRAL CONNECTION  
BY CUSTOMER  
T1  
T2  
0
STATOR  
CUSTOMER  
AC CONNECTION  
GREEN BLACK  
WHITE  
LEGEND  
BCR - BATTERY CHARGE RECTIFIER  
BR1 - BRIDGE RECTIFIER  
BR2 - BRIDGE RECTIFIER  
BR3 - BRIDGE RECTIFIER  
BR4 - BRIDGE RECTIFIER  
IND - INDUCTOR ASSEMBLY  
IM - IGNITION MODULE  
IS - IGNITION SENSOR  
L1 - LIGHT, RUN (OPTIONAL)  
LOP - SWITCH, LOW OIL PRESSURE  
(CLOSES ON LOW PRESSURE)  
ENGINE GENERATOR  
CB1 - CIRCUIT BREAKER, 10A, 2-POLE  
CC - CHOKE COIL  
M
- STEPPER MOTOR THROTTLE CONTROL  
PCB1- CONTROL CIRCUIT BOARD  
R1 - 1 OHM, 50 WATTS  
SC - STARTER CONTACTOR  
SM - STARTER MOTOR  
SW1 - SWITCH, START/STOP  
SW2 - SWITCH, FUEL PUMP PRIME  
SP1 - SPARK PLUG  
- LUG, BARREL  
TC - TERMINAL, CONNECTOR 4 TAB  
TB - TERMINAL BLOCK  
CH - CHOKE HEATER  
F1 - FUSE  
FP - FUEL PUMP ON GASOLINE  
SHUT-OFF VALVE ON L/P  
INV - INVERTER BOX  
HM - HOUR METER  
HTO - SWITCH, HIGH TEMPERATURE OIL  
(CLOSES ON HIGH TEMPERATURE)  
IC - IGNITION COIL  
Page 8-3  
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Part 8  
SPECIFICATIONS & CHARTS  
GENERAL SPECIFICATIONS  
MODEL  
GV-220  
BORE  
STROKE  
DISPLACEMENT  
OIL CAPACITY  
W/O FILTER CHANGE  
WITH FILTER CHANGE  
2.95 inches (75mm)  
1.93 inches (49mm)  
216.5cc  
21 ounces (620ml)  
29.5 ounces (870 ml)  
VALVE TRAIN  
MODEL  
GV-220  
VALVE SEAT WIDTH:  
DESIGN WIDTH  
VALVE SEAT ANGLE  
VALVE MARGIN:  
DESIGN MARGIN  
0.034-0.044 inch (0.87-1.13mm)  
45 degrees  
0.034-0.044 inch  
(0.87-1.13mm)  
INTAKE VALVE STEM  
DIAMETER:  
DESIGN DIAMETER  
0.274-0.275 inch  
(6.965-6.980mm)  
EXHAUST VALVE STEM  
DIAMETER:  
DESIGN DIAMETER  
0.273-0.274 inch  
6.965-6.980mm)  
TAPPET DIAMETER  
INTAKE AND EXHAUST:  
DESIGN DIAMETER  
0.293-0.294 inch  
(7.457-7.475mm)  
VALVE SPRINGS:  
FREE LENGTH  
2.074 inch (52.69mm)  
FORCE REQUIRED TO  
COMPRESS SPRING  
TO 1.39 INCH (35.2mm)  
19.8-21.8 pounds  
(9.0-9.9kg)  
VALVE CLEARANCE:  
INTAKE  
0.001-0.0022 inch  
(0.03O.056mm)  
0.0018-0.003 in.  
(0.07-0.046mm)  
EXHAUST  
VALVE GUIDES:  
DESIGN DIAMETER  
0.237-0.2364 inch  
(6.02-6.005mm)  
CRANKSHAFT END PLAY  
ALLOWABLE  
END PLAY  
0.006-0.023 inch  
(0.14-0.60mm)  
Page 8-4  
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Part 8  
SPECIFICATIONS & CHARTS  
CRANKCASE ASSEMBLY  
MODEL  
GV-220  
CYLINDER BORE:  
DESIGN DIAMETER  
2.953-2.954 inch  
(75.000-75.025mm)  
VALVE TAPPET BORE:  
DESIGN DIAMETER  
0.295-0.296 inch  
(7.494-7.520mm)  
CRANKSHAFT SLEEVE  
BEARING:  
DESIGN DIAMETER  
*(WHERE APPLICABLE)  
GOVERNOR ARM  
BORE:  
1.104-1.106 inch  
(28.044-28.099mm)  
DESIGN DIAMETER  
0.239-0.240 inch  
(6.07-6.10mm)  
CAMSHAFT BEARING:  
DESIGN DIAMETER  
1.024-1.025 inch  
(26.00-26.03mm)  
GOVERNOR ARM  
DIAMETER:  
DESIGN DIAMETER:  
0.235-0.237 inch  
(5.97-6.03mm)  
*Later model small frame GN engines have no crankshaft sleeve bearing.  
CRANKCASE COVER ASSEMBLY  
MODEL  
GV-220  
CRANKSHAFT BEARING  
BORE:  
DESIGN DIAMETER  
1.104-1.105 inch  
(28.040-28.065mm)  
CAMSHAFT BEARING  
BORE:  
DESIGN DIAMETER  
1.299-1.300 inch  
(33.00-33.03mm)  
GOVERNOR GEAR  
SHAFT DIAMETER  
0.236-0.237 inch  
(6.004-6.012mm)  
OIL PUMP INNER ROTOR  
SHAFT DIAMETER:  
DESIGN DIAMETER  
0.353-0.354 inch  
(8.969-8.987mm)  
Page 8-5  
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Part 8  
SPECIFICATIONS & CHARTS  
CRANKSHAFT  
MODEL  
GV-220  
CRANKPIN DIAMETER:  
DESIGN DIAMETER  
1.180-1.181 inch  
(29.99-30.01mm)  
CRANKSHAFT  
MAIN BEARING  
(FLYWHEEL END):  
DESIGN DIAMETER  
1.102-1.103 inch  
(28.000-28.012mm)  
CRANKSHAFT  
MAIN BEARING  
(PTO END):  
DESIGN DIAMETER  
1.102-1.103 inch  
(28.000-28.012mm)  
CONNECTING ROD ASSEMBLY  
MODEL  
GV-220  
LARGE END  
INSIDE DIAMETER:  
DESIGN DIAMETER  
1.183-1.184 inch  
(30.06-30.07mm)  
SMALL END  
INSIDE DIAMETER:  
DESIGN DIAMETER  
2.196-2.213 inch  
(55.8-56.2mm)  
PISTON PIN LENGTH:  
DESIGN DIAMETER  
1.102-1.103 inch  
(28.000-28.012mm)  
PISTON PIN  
OUTSIDE DIAMETER:  
DESIGN DIAMETER  
0.708-0.709 inch  
(17.989-18.000mm)  
PISTON  
MODEL  
GV-220  
PISTON MAJOR  
DIAMETER:  
DESIGN DIAMETER  
2.753-2.754 inch  
(69.939-69.959mm)  
PISTON MINOR  
DIAMETER:  
DESIGN DIAMETER  
2.747-2.748 inch  
(69.789-69.809mm)  
Page 8-6  
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Part 8  
SPECIFICATIONS & CHARTS  
PISTON (CONTINUED)  
MODEL  
GV-220  
WRIST PIN BORE  
DIAMETER:  
DESIGN DIAMETER  
0.708-0.709 inch  
(18.000-18.011mm)  
TOP RING GROOVE  
WIDTH:  
DESIGN WIDTH  
0.059-0.061 inch  
(1.52-1.54mm)  
SECOND RING  
GROOVE WIDTH:  
DESIGN WIDTH  
0.059-0.061 inch  
(1.52-1.54mm)  
OIL CONTROL RING  
GROOVE WIDTH:  
DESIGN WIDTH  
0.118-0.119 inch  
(3.01-3.03mm)  
TOP RING WIDTH:  
DESIGN WIDTH  
0.057-0.059 inch  
(1.47-1.49mm)  
TOP RING END GAP: *  
DESIGN END GAP  
0.005-0.016 inch  
(0.15-0.40mm)  
SECOND RING WIDTH:  
DESIGN WIDTH  
0.057-0.059 inch  
( 1.465-1.490mm)  
SECOND RING END GAP: *  
DESIGN END GAP  
0.006-0.016 inch  
(0.15-0.40mm)  
OIL CONTROL RING  
WIDTH:  
DESIGN WIDTH  
0.111-0.118 inch  
(2.825-3.003mm)  
OIL CONTROL RING  
END GAP: *  
DESIGN END GAP  
0.015-0.055 inch  
( 0.38-1.40mm)  
*NOTE 1: Measure end gap with ring pushed down in cylinder to depth of 2.75 inches  
Page 8-7  
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Part 8  
SPECIFICATIONS & CHARTS  
CAMSHAFT ASSEMBLY  
MODEL  
GV-220  
MAIN CAMSHAFT  
BEARING DIAMETER  
(FLYWHEEL END):  
DESIGN DIAMETER  
1.022-1.023 inch  
(25.96-25.98mm)  
MAIN CAMSHAFT  
BEARING DIAMETER  
(PTO END):  
DESIGN DIAMETER  
1.297-1.298 inch  
(32.96-32.98mm)  
CAM LIFT:  
DESIGN LIFT  
0.210-0.212 inch  
(5.34-5.38mm)  
BASE CIRCLE  
DIAMETER OF CAM:  
DESIGN DIAMETER  
0.978-0.990 inch  
(24.85-25.15mm)  
COMPRESSION  
RELEASE LIFT  
(MEASURED AT TAPPET):  
DESIGN LIFT  
0.027-0.055 inch  
(0.70-1.40mm)  
OIL PUMP  
MODEL  
GV-220  
PUMP TIP CLEARANCE *:  
DESIGN CLEARANCE  
0.0000-0.0010 inch  
(0.000-0.025mm)  
INNER ROTOR BORE:  
DESIGN BORE  
0.354-0.355 inch  
(9.000-9.019mm)  
INNER ROTOR THICKNESS:  
DESIGN THICKNESS  
0.312-0.315 inch  
(7.95-8.00mm)  
OUTER ROTOR  
OUTSIDE DIAMETER:  
DESIGN DIAMETER  
1.296-1.297 inch  
(32.92-32.95mm)  
OUTER ROTOR  
THICKNESS:  
DESIGN THICKNESS  
0.314-0.316 inch  
(8.000-8.025mm)  
*NOTE 2: Measure pump tip clearance on shaft in crankcase cover.  
Page 8-8  
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Part 8  
SPECIFICATIONS & CHARTS  
OIL PUMP (CONTINUED)  
MODEL  
GV-220  
OIL PRESSURE RELIEF  
VALVE SPRING: Force  
required to compress  
spring to 1.035 inch  
(26.3mm)  
0.85-0.95 pounds  
(0.39-0.43kg)  
COMPRESSION PRESSURE  
TORQUE SPECIFICATIONS  
MODEL  
WHILE CRANKING  
(COLD ENGINE)  
GV-220  
60 psi min.  
MODEL  
GV-220  
Rocker Cover Screws  
4 ft-lbs (48 in-lbs)  
Rocker Arm Jam Nut  
Cylinder Head Bolts  
Connecting Rod Bolts  
Flywheel Nut  
14.5 ft-lbs (174 in-lbs)  
22 ft-lbs (264 in-lbs)  
10 ft-lbs (120 in-lbs)  
75 ft-lbs (900 in-lbs)  
18 ft-lbs (216 in-lbs)  
5 ft-lbs (60 in-lbs)  
Crankcase Cover Bolts  
Ignition Coil Bolts  
Spark Plug  
13 ft-lbs (156 in-lbs)  
5 ft-lbs (60 in-lbs)  
Rewind Starter Screws  
Starter Motor Bolts  
Intake Manifold Screws  
18 ft-lbs (216 in-lbs)  
4 ft-lbs (50 in-lbs)  
Carburetor to Intake  
Manifold  
3.3 ft-lbs (40 in-lbs)  
Air Cleaner Box  
(to Carburetor)  
4 ft-lbs (50 in-lbs)  
7 ft-lbs (84 in-lbs)  
Blower Housing Screws  
Upper and Lower Shroud  
Screws  
4 ft-lbs (48 in-lbs)  
Governor Lever Clamp  
Bolt  
5.8 ft-lbs (70 in-lbs)  
9 ft-lbs (108 in-lbs)  
9 ft-lbs (108 in-lbs)  
Page 8-9  
Oil Filter Adapter Bolts  
Low Oil Switch  
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Part 8  
SPECIFICATIONS & CHARTS  
MAJOR FEATURES AND DIMENSIONS  
GENERATOR  
Page 8-10  
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Part 8  
SPECIFICATIONS & CHARTS  
MAJOR FEATURES AND DIMENSIONS  
INVERTER  
Page 8-11  
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