Generac Power Systems 0595-0 User Manual

OWNER'S MANUAL

IM-52, IM-66 AND IM-72

AIR-COOLED

Manual No. 98699

INDUSTRIAL MOBILE
GENERATORS

Model Nos.0595-0, 0860-0, 0861-0

CORPORATION

Revision I (6/9/97)

Printed in U.S.A.

GENERAL SAFETY RULES

THE MANUFACTURER SUGGESTS THAT THESE "RULES” FOR SAFE OPERATION BE
COPIED AND POSTED IN POTENTIAL HAZARD AREAS OF THE GENERATOR. SAFETY

A

SHOULD BE STRESSED TO ALL OPERATORS AND POTENTIAL OPERATORS OF THIS
EQUIPMENT.

Study these SAFETY RULES carefully before operat
ing or servicing applicable equipment. Become familiar
with this Owner's Manual and with your generator.

Safe, efficient and reiiable operation can only be
achieved if generator is properly installed, operated
and maintained. Many accidents are caused by failing
to follow simple and fundamental rules or precautions.

The manufacturer suggests that these GENERAL
SAFETY RULES be copied and posted in potential
hazard areas of the generator. Safety should be
stressed to all operators and potential operators of
equipment.

The manufacturer cannot possibly anticipate every cir
cumstance that might involve a hazard. The \warnings
in this Manual and on tags and decals affixed to the

unit are, therefore, not all-inclusive. If you use a proce

dure, work method or operating technique Generac
does not specifically recommend, you must satisfy
yourself that it is safe for you and others. You must
also make sure the procedure, work method or operat
ing technique that you chose does not render the gen
erator to be unsafe.

For fire safety, the industrial mobile generator must be

A

properly installed and maintained. Installation must

always remain in compliance with applicable codes and
standards. In addition, the generator must be installed
in conformance to the manufacturer's detailed installa
tion instructions. Following installation, nothing must be
done that might render the generator in noncompliance
with such codes, standards and instructions.

The INDUSTRIAL MOBILE generator produces

A

extremely high and dangerous electrical voltages and
can cause dangerous, and possibly fatal, electrical
shock. Avoid contact with bare wires, terminals, etc.
while the unit is running. If you must work around an
operating generator, stand on an insulated, dry surface
to reduce shock hazard.

Never work on this equipment or handle any electrical
device while standing in water, while barefoot, or while
hands or feet are wet. Dangerous electrical shock will result.

Have the generator properly grounded (bonded) during
installation onto the vehicle, either by solid mounting to

the vehicle frame or chassis or by means of an
approved bonding conductor. DO NOT disconnect the
bonding conductor, if so equipped. DO NOT reconnect
the bonding conductor to any generator part that might
be removed or disassembled during routine mainte
nance. If the grounding conductor must be replaced,
use only a flexible conductor that is of No. 8 AWG cop
per wire minimum.

In case of accident caused by electric shock, shut
down the source of electrical power down at once. If

this cannot be done, free victim from live conductor.
AVOID DIRECT CONTACT WITH THE VICTIM. Use a
dry board, dry rope, or other non-conducting imple
ment to free the victim from live conductor.

Inspect fuel system frequently for leaks or damage.
Repair or replace any damaged or leaking component

immediately. Never attempt to change, alter or modify the
generator fuel system in any way that might affect safety
or compliance with applicable codes and standards.

The generator engine gives off DEADLY carbon
monoxide gas through its exhaust system. This dan
gerous gas, if breathed in sufficient concentrations,
can cause unconsciousness or even death. This
exhaust system must have been properly installed, in
strict compliance with applicable codes and standards.
Following installation, you must do nothing that might
render the system unsafe or in non-compliance with
such codes and standards. The generator compart
ment must be completely vapor sealed from vehicle
interior. There must be no possibility of exhaust fumes
entering the vehicle interior. Never operate this equip
ment with a leaking or defective exhaust system.

Never use the generator or any of its parts as a step.
Stepping on the unit can stress and break parts and

may result in dangerous, fuel leakage, oil leakage, etc.
Do not smoke around the generator. Wipe up any fuel,

and oil immediately. Never leave oily or fuel soaked
rags in the generator compartment or on the generator
itself. Keep the area around the generator clean and
free of debris.

Adequate ventilation is required to expel toxic fumes
and gasoline vapors from the generator compartment.
Do not alter the installation of this equipment in any
manner that might obstruct air and ventilation open
ings. Such openings must be kept clear and unob
structed.

Keep hands, feet, clothing, etc., away from drive belts,
fans and other moving parts of this equipment. Never
remove any drive belt or fan guards while the unit is
operating.

Inspect the generator periodically. Repair or replace all
damaged or defective parts immediately

These generators can be converted to use LP gas
(propane) as a fuel. Liquid Propane gas is highly
EXPLOSIVE. The gas is heavier than air and tends to
settle in low areas where even the slightest spark can
ignite the gas and cause an explosion.

Before performing any maintenance on- the generator

set, disconnect its battery cables to prevent accidental
start up. Disconnect the cable from the battery post
indicated by a NEGATIVE, NEG or (-) first. Reconnect
that cable last.

IDENTIFICATION RECORD

Please record the following information from the generator DATA PLATE or information decal.

1.Model Number 2.Serial Number

3.kW Ratina 4. Rated Voltage

5. Phase 6. Hertz

GENERATOR RPM [

FOR SERVICE CENTER LOCATION CALL

800-333-1322 24 HOURS A DAY

GENERAC CORPORATION

WAUKESHA, Wise.

— 1

TABLE OF CONTENTS

GENERAL SAFETY RULES

IDENTIFICATION RECORD....'

...........

inside cover

......................

READ THIS MANUAL THOROUGHLY

Operation and Maintenance

How to Obtain Service.................................................. 3

.........................................

GENERATOR FAMILIARIZATION

■ Generator Applicability

Installation.....................................................................4

Safety

...........................................................................

Generator AC Connection System

..................................................

...............................

OPERATING INSTRUCTIONS

Operating Precautions.................................................. 5

Generator Control Panel

Fuel Primer....................................................................5

Start/Stop Switch...........................................................5

Fuse..............................................................................5

Main Breaker.................................................................5

Remote Start/Stop Switch
Automatic Choke
Before Starting the Engine

Installation.....................................................................6

Engine Lubrication

Fuel Supply...................................................................6

Cooling and Ventilation Air
Engine Exhaust Gas

Starting the Generator................................................. 6

Stopping the Generator................................................ 6

25 Hour Break-In Period................................................6

25 Hour Check-up Period..............................................7

Attention Required After Submersion

Effects of Moisture and Dirt...........................................7

Automatic Low Oil Pressure Shutdown

High Oil Temperature Shutdown
Field Boost

Over Voltage Protection

Engine Governed Speed...............................................8

Fuel Requirements........................................................8

Optional LP Gas Fuel System

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SPECIFICATIONS

Engine Oil Requirements

1

3

4

4
4

5

5

5

5

Engine Specifications,...................................................9

Generator Specifications...............................................9

MAINTENANCE

Checking Engine Oil Level
Change Engine Oil
Change oil filter
Engine Air Cleaner

Clean Air Intake Screen..............................................11

Engine Spark Plugs....................................................11

Fuel Filter....................................................................11

Spark Arrestor Muffler

Cleaning the Generator...............................................12

Battery.........................................................................12

Major Service Manual

Drive Belts...................................................................12

Exercising the Generator
Out of Service Protection
Return the Unit to Service after Storage

...........................................................

TROUBLESHOOTING
ELECTRICAL DATA

6

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.....................................................

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13

....................................

9

10
10
10

11

11

12

12
12
13

14

REPAIR PARTS.....................................15 to 23

6

6

7

7
7
7
7

8

CAL. EMISSIONS WARRANTY

WARRANTY

.......................................

..............

back page

24 - 25

— 2 —

READ THIS MANUAL THOROUGHLY

If you don't understand any portion of this manual,
contact Generac for a demonstration of actuai start
ing, operating and sen/icing procedures.

Throughout this publication and on tags and decals
affixed to the generator, DANGER and CAUTION
blocks are used to alert you to special instruction
about a particular operation that may be hazardous if
performed incorrectly or carelessly. Observe them
carefully.

These safety warnings cannot eliminate the hazards
that they indicate. Strict compliance with the special
instructions while performing the service plus "com
mon sense" are major measures to prevent acci
dents.

The foliowing definitions apply to DANGER, CAU
TION and NOTE blocks found throughout the manual.

[ DANGER: AFTER THIS HEADING YOU CAN READ

A HANDLING, INSTALLING, OPERATING OR SERVIC-

' ING INSTRUCTIONS THAT, IF NOT STRICTLY COM

PLIED WITH, MAY RESULT IN PERSONAL INJURY.

CAUTION: After this heading you can read instruc
tions for handling, installing, operating or servicing
the generator that, if not strictly complied with, may
result in damage to equipment and/or property.

NOTE: After this heading you can read explanatory

statements that require special emphasis.
These symbois indicate the following:

■ Points out important safety information and, if
not followed, could endanger personal safety
and/or property of yourself and others.

Potential explosion hazard

Potential fire hazard

A

The operator (driver) is responsible for proper and
safe use of the vehicle, equipment on the vehicle, and
the safety of all vehicle occupants. We strongly rec
ommend that the operator read this Owner's Manual
and thoroughly understand all instructions before

using this equipment. We aiso strongly recommend

instructing other occupants in the vehicie to properiy
start and operate the generator. This prepares them if
they need to operate the equipment in an emergency.

OPERATION AND MAINTENANCE

It is the operator's responsibiiity to perform all safety
checks; to make sure that all maintenance for safe
operation is performed promptly; and to have the

equipment checked by an Authorized Dealer periodi
cally. Normal maintenance service and replacement
of parts are the responsibility of the Owner/Operator
and, as such, are not considered defects in materials
or workmanship within the terms of the warranty.

Individual operating habits and usage contribute to
the need for maintenance service.

Proper maintenance and care of your industrial

mobile generator assures a minimum number of prob

lems and keeps your operating expenses at a mini

mum. See your authorized Deaier/Distributor for ser
vice aids and accessories.

HOW TO OBTAIN SERVICE

When your industrial mobile generator set requires

servicing or repairs, simply contact an Authorized

Service Facility for assistance. Service technicians
are factory-trained and are capable of handling all of
your service needs.

When contacting an Authorized Service Facility or the
factory about parts and service, always supply the
complete model number and serial number of your

unit as given on its data decal.
The warranty on your generator is included in this

Owner's Manual, as well as listings for repair parts.

Potential electrical shock hazard

A

— 3-

GENERATOR FAMILIARIZATION

GENERATOR APPLICABILITY

These generators have been designed and manufac
tured for supplying electrical power for Industrial mobile
vehicles. You should not modify the generator or use it
for any application other than for what it was designed.

If there are questions pertaining to its application, write
or call the factory. Do not use the unit until you have
been advised by a competent authority.

DANGER; FOR FIRE SAFETY, THE GENERATOR
MUST HAVE BEEN PROPERLY INSTALLED IN COM

A

PLIANCE WITH INDUSTRY STANDARDS. THE GEN

ERATOR ALSO MUST HAVE BEEN INSTALLED IN
STRICT COMPLIANCE WITH THE MANUFACTUR
ER’S DETAILED INSTALLATION INSTRUCTIONS.
AFTER INSTALLATION, DO NOTHING THAT MIGHT
RENDER THE UNIT IN NON-COMPLIANCE WITH
SUCH CODES, STANDARDS AND INSTRUCTIONS.

You can use this generator to supply electrical power
for operating 120/240 volts, single phase, 60 Hertz, a-c
electrical loads requiring the following:

Industrial

Generator (wattage) 120 Volts 240 Volts

IM-52
IM-66
IM-72 7200 60 30

Power

5200 43.3 21.6
6600 55

Amps at Amps at

27.5

SAFETY

Before using the generator set, carefully read GENER
AL SAFETY RULES inside the cover. Comply with
these RULES to prevent accidents and damage to
equipment and/or property. Generac suggests copying
and posting the GENERAL SAFETY RULES in poten
tial hazard areas of the generator. Safety should be
stressed to all operators of this equipment.

GENERATOR AC CONNECTION

SYSTEM

This generator set is equipped with dual Stator a-c
power windings. These two stator windings supply
electrical power to customer electrical loads by means
of a dual 2-wire connection system. Note, however,
that neutral is grounded.

The generator may have been installed so that units
power 120/240 volts AC loads (Figure 1); or you can
wire them to connect only 120 volts AC electrical loads

(Figure 2). Be sure to install jumper wire between the
circuit breakers (C.B. in Figure 2) when reconnecting
for 120 volts.

Figure 1 —Connections for 120/Z40 Volts

CAUTION: Do not overload the generator. Some
installations may require that electrical loads be
alternated to avoid overloading. Applying exces

sively high electrical loads may damage the genera
tor and may shorten its life. Add up the rated watts
of all electrical lighting, appliance, tool and motor

loads the generator will power at one time. This

total should not be greater than the wattage capaci
ty of the generator. If an electrical device nameplate
gives only volts and amps, multiply volts times
amps to obtain watts (volts x amps = watts). Some
electric motors require more watts of power (or
amps of current) for starting than for continuous
operation.

INSTALLATION

This Owner’s Manual has been prepared under the
assumption that a competent, qualified technician
installed the generator into an industrial vehicle. We
also assume the installer complied with all applicable
codes, standards and regulations pertaining to installa
tion.

Owners/Operators should make sure nothing is done
during installation that might render the unit unsafe or
in noncompliance with,applicable codes, standards
and instructions. They should be sure the unit has
been installed to allow adequate ventilation for cooling
and exhaust air.

Figure!—Connections for 120 Volts

GROUNDED

. NEUTIRAL

— 4 —

OPERATING INSTRUCTIONS

OPERATING PRECAUTIONS

WARNING: NEVER OPERATE THE GENERATOR
SET WHILE THE VEHICLE IS PARKED OVER DRY

LEAVES, DRY GRASS OR ANY OTHER COM

FUSE

Protects the engine DC control circuit against electrical
overload. If the fuse element has melted open due to
overloading, the engine cannot be cranked. If you must
replace it, use only an identical replacement fuse.

BUSTIBLE SUBSTANCE. THE GENERATORS
EXHAUST SYSTEM BECOMES EXTREMELY HOT
AND CAN CAUSE FIRE IF IT IS TOO CLOSE TO
COMBUSTIBLE MATERIALS.

WARNING: THE GENERATORS EXHAUST SYSTEM

GIVES OFF DEADLY CARBON MONOXIDE GAS.

THIS DANGEROUS GAS, IF BREATHED IN SUFFI

CIENT CONCENTRATIONS CAN CAUSE UNCON
SCIOUSNESS AND EVEN DEATH. NEVER OPER
ATE THE GENERATOR SET WITH THE VEHICLE
INSIDE ANY GARAGE OR OTHER ENCLOSED
AREA. NEVER OPERATE THE GENERATOR WITH A
LEAKING EXHAUST SYSTEM. CLOSE WINDOWS IN

MAIN BREAKER

Protects generators AC output circuit against overload
and provides a method of turning OFF the generators
120/240 volts a-c output to vehicle circuits. The IM-52
units have 25 amp breakers while the IM-66 and IM-72
generators are equipped with 30 amp circuit breakers
(Figure 4).

NOTE: Refer to THE GENERATOR A-C CONNEC

TION SYSTEM on page 4. Individual installations will
differ. If an overload occurs, the dual breaker will open
the hot stator leads (11 and 44), When the generator
has been connected for 120 volts only, either of the
dual circuit breakers will open stator a-c output leads

No. 11 and No. 33.

THE VICINITY OF THE GENERATOR EXHAUST OUT
LET AND TAKE ANY OTHER STEPS THAT MAY BE

Figure 4—25 Amp Dual Circuit Breaker

NECESSARY TO PREVENT EXHAUST GASES FROM
ENTERING ROOMS OR AREAS OCCUPIED BY PEO
PLE OR ANIMALS.

LINE

BREAKERS

GENERATOR CONTROL PANEL

Mounted on the generator control panel.(Figure 3) are

the following features:

Figure 3 —Generator Control Panel

FUSE MAIN

START 15A BREAKER

STOP FUEL

PRIMER

FUEL PRIMER

Before starting a cold engine (it has not been started in
more than two weeks), you must press this switch to
bring fuel from the tank to the fuel pump. This rocker
type switch springs back into its original position when
you release it. •

START/STOP SWITCH

To crank and start the engine, hold this switch at its
START position. Release the switch when the engine
starts. To stop an operating engine, press and hold the
switch in its STOP position until the engine shuts off.
The switch center position is the RUN position.

— 5-

cm

REMOTE START/STOP PANEL

A remote mounted Start/Stop Panel is available, which
allows you to start and stop the generator engine con
veniently from inside the vehicle.

AUTOMATIC CHOKE

The engine is equipped with an automatic choke.
During engine cranking (Start/Stop switch at START),

a solid state choke module signals the choke solenoid
to acuate a cyclic rate dependent on ambient tempera
ture. The choke solenoid thus opens and closes the
carburetor choke valve only when the engine is crank
ing. When you start it and release the start/stop
switch, choke action stops. As the engine warms, the
carburetor choke valve then opens gradually.

BEFORE STARTING THE ENGINE

IMPORTANT: INSTRUCTIONS AND INFORMATION

IN THIS MANUAL ASSUME THE GENERATOR HAS
BEEN PROPERLY INSTALLED, CONNECTED, SER
VICED, TESTED AND ADJUSTED BY A QUALIFIED
INSTALLATION TECHNICIAN OF INSTALLATION
CONTRACTOR.

INSTALLATION

Generator installation must have been properly com
pleted so it complies with all applicable codes, stan
dards and regulations and with the manufacturer's rec
ommendations.

ENGINE LUBRIG\TION

Have engine crankcase properly serviced with recom
mended oil before starting. Refer to "Maintenance" and
"Specifications" sections for oil servicing procedures
and recommendations.

CAUTION: Any attempt to crank or start the engine
before you have properly serviced it with the recom

mended oil may result in engine failure.

FUEL SUPPLY

The engine must have adequate supply of proper fuel
to operate. Before starting, check that sufficient fuel is
available.

NOTE;

been provided with its own fuei tank. On other installa
tions, the generator may “share” with the vehicle’s fuel
tank. When the vehicle’s tank is shared, some
installers may have installed a generator fuel pick up
tube in the shared tank that is shared tank that is short
er than the vehicle’s pick up tube. When a shorter
generator fuel pick up tube is installed in the tank, the
generator will run out of gas while sufficient fuel
remains in the tank for vehicle engine operation.

On some installations, the generator may have

STARTING THE GENERATOR

To start the generator from either the generator control
panel or from the optional Remote Panel, proceed as
follows:

1. Turn OFF electrical loads, using whatever means provided
in your vehicle (such as a main line circuit breaker or trans
fer switch.

NOTE;

loads by setting the generators main circuit breaker to
“OFF” or “OPEN”. If starting from a Remote Panel,
turn OFF loads using whatever means is provided in
the vehicle (such as a main circuit breaker).

2. If you have not started the engine in more that two weeks,

3. To crank and start the engine, hold the start/stop switch at

4. Let the engine run at no-load for a few minutes to stabilize

5. Turn ON electrical loads, using whatever means provided

If starting from the generator panel, turn OFF

press the Fuel Pump Primer switch and hold it for about 30

seconds to activate the automatic shut-off function.
However, if the engine is warm, skip step 2.

START. Release the switch when the engine starts.

CAUTION: If the engine does not start after it has
been cranking for 15 seconds, release the start/stop

A

switch and try again. Holding the switch for longer
than 15 seconds can damage the starter motor.

and warm up the engine.

(such as a main circuit breaker or transfer switch).

■ COOLING AND VENTILATING AIR

Air inlet and outlet openings in the generator compart

ment must be open and unobstructed for continued

proper operation. Without sufficient cooling and venti

lating air flow, the engine-generator quickly overheats,
which causes it to quickly shutdown. Overheating
could also damage the unit or your vehicle.

ENGINE EXHAUST GAS

Before starting the generator engine, you should be
sure there is no way for exhaust gases to enter the
vehicle interior and endangering people or animals.
Close windows, doors and other openings in the vehi
cle that, if open, might permit exhaust gases to enter
the vehicle.

DANGER: THE GENERATOR ENGINE GIVES OFF
DEADLY CARBON MONOXIDE GAS THROUGH ITS
EXHAUST SYSTEM. THIS DANGEROUS GAS, IF
BREATHED IN SUFFICIENT CONCENTRATIONS,

CAN CAUSE UNCONSCIOUSNESS OR EVEN

DEATH. DO NOT OPERATE THE GENERATOR IF ITS
EXHAUST SYSTEM IS LEAKING OR HAS BEEN

DAMAGED. SYMPTOMS OF CARBON MONOXIDE
POISONING ARE (A) INABILITY TO THINK COHER
ENTLY, (B) VOMITING, (C) TWITCHING MUSCLES,
(D) THROBBING TEMPLES, (E) DIZZINESS, (F)
HEADACHE, (G) WEAKNESS AND SLEEPINESS. IF
YOU FEEL ANY OF THESE SYMPTOMS, MOVE INTO
FRESH AIR IMMEDIATELY. IF SYMPTOMS PERSIST,
GET MEDICAL HELP. .

STOPPING THE GENERATOR

1. Turn OFF all electrical loads, using whatever means pro
vided (such a main circuit breaker or transfer switch).

2. Place start/stop switch in its STOP position.

25 HOUR BREAK-IN PERIOD

The first 25 hours of operation is the break-in period for
the generator. Properly breaking in the generator is
essential to reducing oil consumption and enhancing
engine performance. During the break-in period,
observe the following rules:

• For the first 25 hours, run the generator at varying electri
cal loads, to help set the engine piston rings properly.

• Following the initial 25 hour break-in period, avoid light
electrical loads tor the next 75 hours of operation. The unit
should be loaded at 50% (or more) of its capacity during
those 75 hours. Repeated light loads during break-in peri
od may improperly seat the piston rings, resulting in blow­by and high oil consumption.

• Check oil level frequently during the break-ln period. Add
oil if needed. It Is natural for the generator engine to con
sume more oil than is normal until the piston rings have
seated properly.

• When the 25 hour break-in period is done, complete the
tasks recommended under 25 HOUR CHECK-UP PERIOD.

— 6

25 HOUR CHECK-UP PERIOD

After the first 25 hours of operation have been com

pleted, contact an Authorized Service Facility for the

following maintenance. The Owner/Operator is

responsible for any changes.

• Change engine crankcase oil and oil filler.

• Check all cooling system ventilation openings on the vehicle.

• Check engine carburetor adjustments.

• Check engine ignition system.

• Inspect the entire electrical system.

• Inspect the engine exhaust system.

ATTENTION REQUIRED AFTER

SUBMERSION

If the generator has been submerged in water, it must

NOT be started or operated. Following any submersion
in water, have an authorized Generac Service Facility
thoroughly clean and dry the generator.

EFFECTS OF MOISTURE AND DIRT

Keep the generator set as clean,and dry as possible.

Protect unit against excessive dust, dirt, corrosive
vapors, road splash, etc. Permitting dirt and moisture
to accumulate on generator windings will have an
adverse effect on the insulation resistance of those
windings.

When moisture is allowed to remain in contact with
windings, some of the moisture will be retained in voids
and cracks in the insulation. This causes a reduced

insulation resistance and will eventually cause prob

lems. Dirt will make the problem worse, since dirt tends
to hold moisture in contact with windings. Salt (as from

sea air) will also worsen the problem since it tends to

absorb moisture from the air. Salt and moisture, when

combined, form a good electrical conductor.

AUTOMATIC LOW OIL PRESSURE

SHUTDOWN

The engine is equipped with a normally-closed (N.C.)

oil pressure switch (Figure 5). Engine oil pressure

holds the switch open during cranking and operation.

Should oil pressure drop below about 8-10 psi, the

switch contacts close and the engine automatically

shuts down.

HIGH OIL TEMPERATURE

SHUTDOWN

An oil temperature switch (Figure 5) with normally­open (N.O.) contacts is mounted on the engine.
Should engine oil temperature exceed about 284°F
(140°C), the switch contacts close and the engine
shuts down.

FIELD BOOST

The controller Circuit Board houses a field boost diode­and resistor. These two components are part of a
“field- boost” circuit (Figure 6).

Figure 6 — Field Boost Circuit,

During engine cranking only, a positive DC (battery)
voltage is delivered through the diode, resistor, brush
es and slip rings, and to the generator rotor.
Application of this voltage to the rotor “flashes the field”
whenever it is started. Flashing of the field each time
the generator starts makes sure that a sufficiently
strong magnetic field is available to produce the

required “pick up" voltage in the stator windings.

OVER VOLTAGE PROTECTION

A solid state voltage regulator (Figure 7) controls the
generators AC output voltage. This regulator supplies
an excitation current to the rotor. By regulating the

rotor’s excitation current, the strength of its magnetic
field is regulated and, in turn, the voltage delivered to
connected electrical loads is controlled. When the AC
frequency is 60 Hz, voltage is regulated at 120 volts

(voltage-to-frequency ratio is 2-to-1).

Figure 7 — Solid State Voltage Regulator

Figure 5 — Oil Pressure and Temperature Switches

O—TO ROTOR

The voltage regulator also incorporates a “voltage
surge protection circuit." This circuit prevents trouble
some surges in the generator AC output voltage.
Voltage surge is a common cause of damage to elec
tronic equipment.

— 7 —

j (O'^eCT CURnÇNT)

FROM STATOR

eXCn'ATIONWINOINQ

{ALTERHATINO CURRENT)

ENGINE GOVERNED SPEED

The generator is equipped with a 2-pole revolving field

(rotor) which must be driven at 3600 rpm to produce
the unit’s rated a-c frequency of 60 Hz. The gas
engine governor was factory set to about 62 Hz.

(3720) at no-load. After installing it, the technician
should check and adjust the governed speed. Setting
no-load frequency slightly high helps prevent exces
sive frequency, rpm and voltage droop under heavy
electrical loading.

DANGER: DO NOT TAMPER WITH THE ENGINE
GOVERNOR SEHINGS. EXCESSIVELY HIGH

ENGINE SPEEDS ARE DANGEROUS AND
INCREASE THE RISK OF PERSONAL INJURY AND
DAMAGE TO EQUIPMENT AND/OR PROPERTY.
EXCESSIVELY LOW SPEEDS IMPOSE A HEAVY
LOAD ON THE ENGINE WHEN ADEQUATE ENGINE
POWER IS NOT AVAILABLE AND MAY SHORTEN
ENGINE LIFE. THE GENERATOR SUPPLIES COR
RECT RATED FREQUENCY AND VOLTAGE ONLY AT
THE PROPER SPEED. SOME ELECTRICAL
DEVICES MAY BE DAMAGED BY INCORRECT FRE
QUENCY AND/OR VOLTAGE. IF ENGINE SPEED
APPEARS TO BE INCORRECT, CONTACT YOUR
NEAREST AUTHORIZED SERVICE FACILITY.

FUEL REQUIREMENTS

These generators are equipped with gasoline fuel sys
tems as standard equipment. Specific installations

may provide either a separate fuel tank for the genera
tor, or the generator may “share” the vehicle engine's
fuel tank.

NOTE:

have a generator fuel pickup tube that is shorter than
the vehicle engine’s pickup tube. Such an arrange
ment causes the generator engine to “run out of gas”

while adequate fuel for the vehicle remains in the tank.
To reduce lead and carbon deposits use high quality

UNLEADED gasoline with the generator. Leaded
REGULAR grade gasoline is an acceptable substitute.

Installations using a “shared” fuel tank may

CAUTION: Generac does not recommend using any
gasoline containing alcohol (such as “gasohoi”). If

A

you use any gasoline containing alcohol, it must not

contain more than 10 percent ethanol and it must be
removed from the tank during storage. Do NOT use

any gasoline containing methanol. If you use gaso

line with alcohol, inspect more frequently for fuel
leaks and other abnormalities.

OPTIONAL LP GAS FUEL SYSTEM

This generator may be equipped with an optional liquid
propane (LP) gas fuel system (Model 9051)’. LP gas is
usually supplied as a liquid in pressure tanks (Figure 8).

The IM series generators require a “vapor withdrawal”
type fuel system. This type of gaseous fuel system

uses the vapors forming above the liquid fuel in the
storage tank. Air temperatures around the storage
tank must be high enough to sustain adequate fuel
vaporization. In colder climates, you may need to use
an independent heat source to be sure the fuel suffi
ciently vaporizes in the storage tank.

LP gas may consist of propane, butane, or a mixture of
the two gases. Propane vaporizes at temperatures as
low as -20°F (-29°C), but butane returns to its liquid
state when the temperature drops below about 32°F
(0°C). For that reason, a higher ratio of propane is
desired in the gas mixture when temperatures drop
below freezing.

WITHDRAWAL
TANK

Figure 8 —Typical LP Gas Fuel System

FUEL

LOCKOFF

— 8 —

SPECIFICATIONS

ENGINE OIL REQUIREMENTS ENGINE SPECIFICATIONS

Use a high quality detergent oil classified “For Service Type of Engine
SF” and with an oil viscosity rating of SAE 10W-30 oii. Cooling Method

Do not pour in any additives to the recommended oil. Rated Horsepower.........................16 at 3600 rpm

MAINTENANCE section for oil level check and filling compression Ratio

proce ures. Cylinder Block................................Aluminum with cast

'2, ■! -5 V-2- 2®® Displacement

GENERATOR SPECIFICATIONS

..............................................

.............................

.................................

...........................................

.....................................................iron sleeve

Type of Governor

.....................................................

Engine Governed Speed
Air Cleaner

.....................................................

Starter

...........................................

Ignition System

.....................................................

Recommended Spark Plugs

Champion:

Spark Plug Gap

..........................

...............

....................................

.............................

.................................

.............................

Twin Cylinder
Air-cooled

479.4cc

8.6 tol

Mechanical, fixed

speed
See chart below

Paper element with

foam pre-cleaner
12 volts DC electric
Solid state with

flywheel magneto

RC12YC

0.030 inch (0.76mm)

SERIES

Rotor RPM

Rotor Poles

Engine RPM

Wattage*

Voltage*
Current*

Phase

Frequency

Weight
Length

■ 25 inches

Width

* All units are reconnectable to 120 volts, single voltage output.

IM-52G

3600

2
2300
5200

240 240

21.7ACampsi
1

60 Hertz

185 pounds

18.5 inches

t Rated maximum continuous current at 120 volts is 43.3 amps,

t Rated maximum continuous current at 120 volts is 55 amps.
V Rated maximum continuous current 120 volts is 60 amps.

IM-66G IM-72G

3600 3600

2 2
2700
6600

2900
7200

240

27.5 ampst

30 AC ampsV

1 1

60 Hertz

60 Hertz

194 pounds 200 pounds

25 inches

18.5 inches

25 inches

18.5 inches

— 9 —

MAINTENANCE

This section includes information about simple mainte

nance which includes the following tasks:

• Checking engine oil level.

• Changing engine oil.

• Changing oil filter.

• Changing the air cleaner.

• Cleaning the air intake screen.

• Cleaning spark plugs.

CHECKING ENGINE OIL LEVEL

Check engine crankcase oil level at least every eight
hours of operation, or before each use (Figure 9).

• Be sure the generator is as level as possible.

• Remove oil dipstick and wipe dry with clean, lint-free cloth.

• Install and tighten oil dipstick, then remove again.

• Oil should be at dipstick FULL mark. If necessary, add the
recommended oil to the FULL mark only, DO NOT FILL

ABOVE “FULL’ MARK.

• Install and tighten oil dipstick cap before operating the

engine.

NOTE; See “Engine Oil Requirements” on Page 9 for

recommended oils.

Figure 9 —Oil Dipstick and Fill Tube

Remove oil dipstick and fill crankcase with the recom
mended oil (See Page 9). The engine crankcase can hold

about 1.7 liters. DO NOT FILL ABOVE “FULL” MARK.

Install and tighten dipstick cap before operating engine.

CHANGE OIL FILTER

Replace the engine oil filter after the first 25 hours of
operation, every 200 operating hours thereafter.

• Turn oil filter counterclockwise to remove (Figure 11).

• Coat gasket of new filter with engine oil.

• Turn new filter clockwise until its gasket contacts tightly
with the filter adapter. Then tighten with an additional 3/4
to one turn by hand.

• Run engine and check for leaks.

NOTE: Check oil level and fill to full mark after check
ing for leaks. Filter will retain some oil.

CHANGE ENGINE OIL

Change engine oil after the first 25 hours of operation

(after the 25 hour break-in period. Page 6). Thereafter,

change oil every 100 operating hours. Change oil more

frequently if operating consistently under heavy load or

at high ambient temperatures.

• Warm up engine for at least five minutes, then shut down.

• With engine still warm from running, remove cap from oil
drain hose (Figure 10). Drain oil completely into a suitable
container.

• When oil has drained, install and tighten drain hose cap.

Figuren —Engine Oil Filter

10

ENGINE AIR CLEANER

Clean and re-oil the foam pre-cleaner every three

months or ever 25 hours of operation, whichever
occurs first. Service the foam pre-cleaner more fre
quently if you operate the generator in extremely dusty
or dirty conditions (Figure 12):

• Turn KNOB counterclockwise to loosen.

• Remove COVER, FOAM PRE-CLEANER and PAPER FIL

TER.

• Remove foam pre-cleaner from cover

• Wash foam pre-cleaner in liquid detergent and water.

• Wrap foam pre-cleaner in a cloth and squeeze dry.

• Saturate foam pre-cleaner in engine oil. Squeeze to
remove excess oil and to distribute oil.

• Install foam pre-cleaner into cover, followed by paper filter.

Tabs at edges of paper filter must lock into slots on cover.

Once each year or every 100 operating hours
(whichever comes first), replace the paper filter. The
new replacement filter must be a flame retardent type.

Figure 12—Engine Air Cleaner

ENGINE SPARK PLUG

Clean engine spark plug and set gap to 0.030 inch
(0.76mm) every 100 hours of operation (Figure 14).

■Clean by scraping or wire brushing and washing with
commercial solvent. DO NOT BLAST CLEAN SPARK
PLUG.

CAUTION: Sparking can occur if wire terminal does

not fit firmly over spark plug terminal end. If neces
sary, reform wire terminal to obtain a tight fit.

Figure 14 — Engine Spark Plug

1"====*=*^ PAPER

FILTER

FOAM
PRE

CLEANER

COVER

CLEAN AIR INTAKE SCREEN

Clean all foreign material from the air intake screen
(Figure 13) at lease once every 100 hours of operation.
Clean more often if necessary.

Inspect the area around the generator exhaust muffler
periodically and remove all grass, leaves, dirt, etc. from

this area.

Figure 13 — Cleaning Air Intake Screen

hours of operation or once each year, whichever
occurs first.

Figure 15 — Fuel Filter

SPARK ARRESTOR MUFFLER

If the generator is not equipped with a spark arrestor
exhaust muffler and is to be used on any forest cov
ered, brush covered or grass covered unimproved
land, you may have to install a spark arrestor. The
spark arrestor must be maintained in effective working
order by the vehicle owner/operator.

For assistance in ordering, installing and maintaining
spark arrestor exhaust mufflers, contact your nearest
authorized service facility.

Exhaust mufflers supplied by Generac are spark
arrestor types. Generac exhaust mufflers for IM gener
ators do not have a spark arrestor screen, but are of
the more efficient “toriod” or “swirl" type. To remove
carbon and combustion deposits from such mufflers,
remove the PLUG from muffler and run engine for
about 15 minutes. Shut engine down, let the muffler
cool and install the plug.

— 11

WARNING: BE SURE TO RE-INSTALL THE PLUG
FROM THE MUFFLER TUGHTLY. ENGINE VIBRATION

COULD CAUSE A LOOSE PLUG TO FALL OUT. WITH
OUT THE PLUG IN PLACE, HOT ENGINE EXHAUST IS
DIRECTED OUT THE OPENING. THIS HOT EXHAUST,
DEPENDING ON THE INSTALLATION, COULD BE
DIRECTED TO AREAS NOT ABLE TO WITHSTAND

THE EXTREME HEAT SUCH AS WOODEN FLOOR

BOARDS OR OTHER FLAMMABLE MATERIAL. THIS

COULD RESULT IN A RRE.

CLEANING THE GENERATOR

Keep your generator set as clean and dry as possible.
Dirt and moisture that are permitted to accumulate on
electrical windings have an adverse affect on the insu
lation resistance of those windings.

Moisture that is allowed to remain in contact with wind
ings will be retained in voids and cracks of the wind
ings. Dirt makes the problem worse, since it tends to
hold the moisture into contact with the windings. Salt,
as from sea air, worsens the problem since it tends to
absorb moisture from the air. The combination of salt
and moisture makes a good electrical conductor.

DANGER: BAHERY ELECTROLYTE FLUID

IS AN EXTREMELY CAUSTIC SULFURIC ACID

A

SOLUTION THAT CAN CAUSE SEVERE BURNS. DO
NOT PERMIT FLUID TO CONTACT EYES, SKIN,
CLOTHING, PAINTED SURFACES, ETC. WEAR PRO
TECTIVE GOGGLES, PROTECTIVE CLOTHING AND
GLOVES WHEN HANDLING A BAHERY. IF YOU
SPILL THE FLUID, FLUSH THE AFFECTED AREA
IMMEDIATELY WITH CLEAR WATER.

DANGER: DO NOT USE ANY JUMPER CABLES OR
BOOSTER BAHERY TO CRANK AND START THE
GENERATOR ENGINE. IF ANY BAHERY HAS DIS
CHARGED, REMOVE IT FROM THE VEHICLE FOR
RECHARGING.

MAJOR SERVICE MANUAL

To obtain a service manual for your generator, order it
from your dealer/distributor or contact the factory. Be
sure to identify your unit’s MODEL NUMBER and
SERIES.

CAUTION! Do NOT use a forceful spray of water to
clean the generator. Water will enter the generator
interior and cause problems, and may also contami
nate the generator fuel system.

BATTERY

All lead-acid storage batteries will discharge when not
in use. Inspect the generator battery as follows:

ONCE WEEKLY

Inspect battery .posts and cables for tightness, corro

sion. Clean and/or tighten as necessary.
Also check battery fluid level, and, if necessary, fill with

DISTILLED WATER ONLY. DO NOT USE TAP

WATER IN BATTERY.

EVERY SIX MONTHS

Have the battery state of charoe and condition
checked by an automotive service facility. This should
be done with an automotive type battery hydrometer.

DANGER: STORAGE BAHERIES GIVE OFF EXPLO

SIVE HYDROGEN GAS. THIS GAS CAN FORM AN

EXPLOSIVE MIXTURE AROUND THE BAHERY FOR

SEVERAL HOURS AFTER CHARGING. THE SLIGHT

EST SPARK CAN IGNITE THE GAS AND CAUSE AN

EXPLOSION. SUCH AN EXPLOSION CAN SHAHER
THE BAHERY AND CAUSE BLINDNESS OR OTHER
INJURY. ANY AREA THAT HOUSES A STORAGE
BAHERY MUST BE PROPERLY VENTILATED. DO
NOT ALLOW SMOKING, OPEN FLAME, SPARKS OR
ANY SPARK PRODUCING TOOLS OR EQUIPMENT

NEAR THE BAHERY.

DRIVE BELTS

The engine drives the generator rotor by means of a
pulley and drive belt arrangement. The drive train,
drive belt and pulleys are warranted for the life of the
generator. Drive belt ension was properly adjusted
before the unit was shipped form the factory. If you
suspect that drive belt tnesion is incorrect, contact an
autorized service facility.

EXERCISING THE GENERATOR

Generac recommends that you start and operate the
generator at least once every seven days. Let the unit
run for at least 30 minutes to “exercise” the engine.

OUT OF SERVICE PROTECTION

If you cannot exercise the generator every seven days
and it is to be out of service longer than 30 days, pre
pare the generator for storage as follows:

• Start the engine and let it warm up.

• V\/hile the engine is still warm from running, drain the oil
completely. Refill crankcase with recommended oil. See
“Specifications."

• Attach a tag to the engine indicating the viscosity and clas
sification of the oil in the crankcase.

• Remove spark plug and add about 1/2 ounce (15ml) of
clean, fresh engine oil into spark plug threaded openings.
Crank engine several times to distribute oil, then install and

tighten spark plug.

• Remove the battery and store in a cool, dry room on a

wooden board. Never store the battery on any concrete or
wooden floor.

• Clean and wipe the entire generator.

— 12 —

RETURN UNIT TO SERVICE

AFTER STORAGE

To return the unit to service after storage, proceed as
follows:

• Check fag on engine for oil viscosity and classification.
Verify that the correct recommended oii is used in engine.
If necessary, drain and refill with proper oil.

• Check battery. Fill all cells to the proper level with distilled
water. DO NOT USE TAP WATER IN THE BATTERY.
Recharge battery to 100% state of charge, or, if defective,

replace the battery.

• Press the Fuel Pump Primer switch and hold it for about 30
seconds to activate the automatic shut-off function.

• Turn OFF all electrical loads, then start the engine.

• Let engine warm up.

• Apply electrical loads to at least 50% of the unit's rated
wattage capacity.

♦. When engine is thoroughly warmed up, shut it down.

THE GENERATOR IS NOW READY FOR SERVICE.

TROUBLESHOOTING

PROBLEM

Engine won't crank.

Engine cranks but won't start. 1.

Engine starts hard, runs rough. 1.

Engine starts, shuts down

when Start/Stop switch is

released.

POSSIBLE CAUSES

1.

15 amp fuse is blown

2.

Loose corroded or defective
battery cables.

3.

Defective engine Start/Stop switch.

4.

Defective starter contactor.

5. Defective starter motor.

6. Low Battery Voltage.

Out of fuel.

2.

Fuel pump is defective.

3.

Open Wire #14 from Eng. Control Bd.

4.

Engine is flooded.

5.

Spark plug defective.

Air cleaner plugged or damaged

2.

Defective spark plug.

1.

Engine oil is low.

2.

Engine is overheated.

3. Defective Low Oil Pressure System

4.

Defective Engine Control Board

REMEDY

1.

Replace 15 amp fuse

Tighten, clean or replace

2.
as necessary.

3. Replace Start/Stop switch.

4. Replace contactor.

Replace starter motor.

5.

6. Charge or replace battery.

Replenish fuel.

1.

Replace fuel pump.

2.

3. Reconnect wire.

4. Wait 5-10 min. before trying.

5. Clean, regap or replace plug.

Clean or replace as needed.

1.

Clean, regap or replace plug.

2.

1. Check oil; add as needed.

2. Check adequate ventilation.

Have serviced/replaced.

3.

4. Have board serviced/replaced.

Start/Stop switch at Stop,

engine continues to run.

No AC output from generator.

1.

Defective Start/Stop switch

2.

Open/disconnected wire #18 between
Start/Stop switch and Engine Control

3.

Open/disconnected wire #0 between
Start/Stop switch & Engine Control Bd.

4.

Defective Engine Control Board

1.

Check circuit breaker.

2.

Check vehicle circuit breaker & fuses.

3.

Generator internal failure

13 —

1. Replace switch.

Reconnect or close wire.

2.

Reconnect or close wire.

. 3.

Replace board.

4.

Reset to ON or CLOSED.

1.

Reset and replace if necessary.

2.
Take generator to an

3.
Authorized Generac facility.

ELECTRICAL DATA

Drawing No. 92851

1-

g

it

M

-----

— 14'

Drawing No. 98740

EXPLODED VIEW — SHEET METAL

ITEM

10 87750
11
12

13
14

15
16 74902 2

17
19

20

PART NO.

1

SEE ENGINE EXPLODED VIEW- OF ENGINE
67877 1

2

67198N 1

3
4 67890 1
5 87865

7

86313

8 56893 23

74916
74908

73190
78858

78859

66886 2
73191
48571

QTY. DESCRIPTION

KEY, WOODRUFF
6x25
WASHER, BELLEVILLE
NUT, HEX-M20-1.50 24

1

PLUG, FLYWHEEL 25 73186
ACCESS

1

HOUSING, ENGINE TOP
SCREW (CRIMPTITE)
NO. 10-24 X 1/2”

1

SCROLL, FLYWHEEL

1

COVER-BASE #2

9

SCREW (TAPTITE)
M5x 10MM

1

WRAPPER-NO. 2
CYLINDER

1

COVER. VALLEY ASSEMBLY-CYL. #1

1

WRAPPER-NO. 1
CYLINDER
WRAPPER-BARREL
CAPSCREW, HEX HEAD
M6-1.00X 12MM

1

COVER, BASE-NO. 1 41 92934
CYLINDER

2

CAPSCREW, HEX HEAD
M8-1.25 X 10MM

ITEM

23

29 67866

33 87858A
34 29289

35
36

37
38
39
40

42

PART NO.

22129

21

75246

22

010-74260

88290

26 81108
27

22717B

28 22717A

77001

30

73132

31

87858B
50277

38153
22152
33469
23897 2

22158

QTY. DESCRIPTION

2

LOCKWASHER-M8

4

SCREW(TAPTITE)
3/8"-16x 1-1/4”

1

WIRE ASSEMBLY-NO. 16

■ 1

2FT.

COVER, STARTER

1

WRAPPER, CRANKCASE

1

BUSHING, SNAP

1

GROMMET-RUBBER
2 GROMMET-RUBBER
1

0-RING
1

PLUG, OIL FILL

BOOT, SPARK PLUG

2

1 GROUND WIRE

ASSEMBLY-CYL. #2

FOAM TAPE

GROUND WIRE

1
1 DECAL, OIL DRAIN

2 #10-32x1-1/2” SCREW-

NO. 10 LOCK WASHER

2

0.22 INCH I.D. SPACER

2

NO. 10 FLAT WASHER

REGULATOR-1 OA.

1

2 NO. 10-32 HEX NUT

— 15'

EXPLODED VIEW — BASE & PULLEYS

Drawing No. 98739

—16 —

Drawing No. 98739

REPAIR PARTS — BASE & PULLEYS

ITEM PART NO.

86318

1

68527

2

46911

3

25017

4

22237

5
6 22129 4

77603

8

22259

9

10

11

52858
51730

12 29459
13

75215
14 73146 4
15
16

75209

73174
17 79678

18 55173 4

19

21

72383

75224E 1

75224F

75224G 1

22 73106E 1

73106F

73106G 1

23
24
25

26

75216

49451 1

42633 1

77017

27 73118 1
28 74906
29 74908 1
30 72375

31
32

73185 1

22097 2

33 77682 1
34

75242 4

35 49813 2
36

37

45757

90859

38 48031E 2
43 75710 1
44

74958 1

QTY.

1
2
4
8

DESCRIPTION

BASE, MOUNTING
HHCS-M6-1.0X20LG

MOUNT, (RUBBER)
CAPSCREW, HEX HD.­3/8"-16x1/2*

8

LOCKWASHER, M10 52

LOCKWASHER-M8

.-..SIf:iD.,^RUaB.EBilVID.U.NJ».^

2
2
6
2

HHCS-5/16-18X3.5SPC

NUT, HEX-5/16-18

NUT, FLANGED LOCK-M8-1.25

CAPSCR. HEX HD.,
M8-1.25X60MM

2
2

SPRING, BELT TENSION
WASHER, SPRING CNTR

SLIDE (NYLON)

2

1

SUPPORT, NYLON SLIDE

MANIFOLD, EXHAUST

2 GASKET, EXHAUST

MANIFOLD

CAPSCR., HEXHD.-M8-1.25
X20MM (GRADE 10.9)

2

GASKET, COLLECTOR PAN

PULLEY, ENGINE-5.2

1

PULLEY, ENGINE-6.6 71 43182

PULLEY, ENGINE-7.2

PULLEY, ALT.-5.2

1

PULLEY, ALT.-6.6

PULLEY, ALT.-7.2

1

BELT (POLY V 4L)-40“
WASHER, PULLEY

CAPSCR., SOCKET HD.
3/8”-24 X 1 (GRADE 5)

1

GUIDE, BLOWER HOUSING
CAPSCR., HEX HD.

3/8”-24 X 2-1/4"

11

SCREW (TAPTITE)
M6-1.00X20 M6-1.00X 16MM WITH

SCREW (TAPTITE)
M5-0.80X10

1

HOUSING, BLOWER
SPACER, BLOW. HOUSING
LOCKWASHER, M6
CAPSCR. HEX HD.

M5-0.80 X 80MM
SPRING, GENERATOR SET MT
NUT, HEX M6X 1.0

2

CAPSCREW, HEX HD.,
M6-1.0X25LONG

1

COVER PLATE
CLAMP, HOSE-3«”
TUBE, OIL RLL AND DRAIN
CAP & DIPSTICK ASSEM.

ITEM PART NO.

45

67871 1 0-RING, CAP
46 75712
47

75711 1
50 43790
51

47290

35461

53 69811

54 65852

55
56
57
58
59
60
61
62
63

81105
73179
70185
60108
74948
74950
74951
73134
38750

64 74949
65
66
67
69
70

73
74
75
76

68548
62684
29289
75281
74027

75237
77681
75474
90800

77 94670
78
79

80
81
82

75226
56893

75229
75227
79246

83 22473
85

72384C
87 77643
90

22447

91 91123

92 45756

93
94

95
96

87769

87768

87770

90088
97 90475

QTY.

DESCRIPTION

1 0-RING, DRAIN

PIPE, OIL DRAIN ADAPTOR
1
1
1

1

1

2

ELBOW-3/8'NPTX 3/8”

HOSE, 3/8 XI0-1/2”

FITTING, B/VRBED -1/4” NPT

CAP, HEX-1/4” NPT

CUP, HOSE RETAINER

NUT, FLANGE 5/16-18 LOCK
1 OIL FILTER SUPPORT
1 FILTER, OIL
1 10 PSI OIL PRES. SWITCH

3

FITTING-5/16"
1 TUBE, OUTER OIL

1 TUBE, INNER OIL
1 ADAPTOR, OIL PAD

3

CAPSCREW, HEX HEAD-

M6-1.00X30MM

1

FITTING, 90-DEGREE-5/16"

1 GASKET, OIL PAD
1

-

LUG, GROUNDING

TAPE, FOAM-1/16" THICK x 8'

1 SWITCH, HIGH TEMP,
2 SCREW, PAN HEAD-M3-0.50
2 LOCKWASHER-M3
4 WASHER, SPRING RETAINER

1 CAP, VINYL-LOS-2 WIRE

1

CAP, VINYL-17D x 42L X 2H

1 ELBOW, EXHAUST

- UNIVERSAL
1 CLAMP, EXHAUST-1-1/8"
1

COVER, AIR

23 SCREW (CRIMPTITE)

NO. 10-24 X 1/2" LONG

1 GASKET, SLIDE PAN

1 SLIDE PAN
4

CAPSCREW, HEX HEAD

LOCK WASHER
4
1
1
1

FLATWASHER, M6

COVER, EXHAUST OUTLET
GASKET, EXHAUST OUTLET
LOCK WASHER-M6,

TOOTHED

1

FUEL PUMP BRACKET

5 M6X 10MM TAPTITE

SCREW

1

FUEL FILTER

1 1/8” PIPE TO 1/4” TUBE

FITTING
1
1

FUEL LINE

VINYL COATED CLAMP
1 FUEL PUMP

— 17 —

EXPLODED VIEW — CONTROL PANEL

Drawing No. 98738

Drawing No. 98738

REPAIR PARTS — CONTROL PANEL

ITEM PART NO.

75995

1

77005G

2

77004G

80095G

20765

3

20766

92848

4 73159 1

31971 1

5

72379

6

7 77006

52858 8

8
9 66386

66849 2

10

27756

11

86314 1

12

14 22473

22097

15
17 90141 2

22447

18

74906

19

92234 1

20

010-74260

21
22 22129

22259 2 5/16-18 HEX NUT

23

86316A 1

24

53650

25

91915 1

26

75244 1

27

66886

28

86729

29
30 75476

22264 7

31

38077 1

32

90987 2 •

33

86317 . 1

34

75235

35

QTY.

1

1
1
1
1
1

1

1

4

1

4

2
4

1

4

1
2

1

2
1
4

4

DESCRIPTION

LOWER BEARING
CARRIER
ROTOR ASSEM. IM52G 38

ROTOR ASSEM. IM66G

ROTOR ASSEM. IM72G 39
STATOR ASSEM. IM52G 41
STATOR ASSEM. IM66G
STATOR ASSEM. IM72G

BALL BEARING 43
BALL BEARING

UPPER BEARING
CARRIER 47
STUD-STATOR 82081

M8-1.25 FLA.NGE LOCK NUT

BRUSH HOLDER

M5-0.8X16LG. TAPTITE 49

NYLON WASHER 50
GENERATOR TOP

HOUSING

M6-FLAT WASHER 51

M6-LOCK WASHER 52
GROUND CABLE
SHAKEPROOF LOCK
WASHER

M6-1.0X20 LG. TAPTITE 55

CONTROLLER P.C.B.
STARTER CABLE
5/16 LOCK WASHER

PANEL SHEET METAL 58
4-PIN CONNECTOR 59

CONNECTOR

REMOTE HARNESS

M6-1.0 X 12MM CAPSCREW
STARTER CONTACTOR 62 31791

M4-0.7X 16 LG. CAP 63

M4 LOCK WASHER
CIRCUIT BREAKER 15A.

M3-0.5 X 12 LG. CAPSCREW 66

PANEL SUPPORT BRK.T

M5-0.8 X 30 LG. CAPSCREW

ITEM

36
37 49813

44
45 51716

48

53
54

56
57 23365

64 74908
65

67

PART NO.

82737

49815

43182 2 M3-LOCK WASHER
53623
54502 1

83049

22152 6 .

74968

25105

86315

90734 4

22985
32300
22676
87798

92113

7521OA

51715
90157 1

90157A 1

23897

23484S
93846
75763A

QTY.

DESCRIPTION

4

VIBRATION MOUNT

4

M6-1.0 HEX NUT

1

M5-08X 16 LG. HEX
HD.CAPSCR.

1

C/BREAKER 2.5A. IM52G
C/BREAKER 3.0A. IM66G,

IM72G

1 REGULATOR VOLTAGE

M5-LOCK WASHER
M5-0.8 HEX NUT

4

1 C/BREAKER 25A. IM52G

C/BREAKER 30A. IM66G,

1

IM72G

4

PRHMS #6-32 X 1/4 SEMS
PANEL COVER

1

M4-0.7X 16 LG. CAPSCR.

W/LOCK-WASHER &

FLAT WASHER
M4 FLAT WASHER

3

FUSE HOLDER

1
1 FUSE AGC-15A.

SWITCH S.P.D.T.

1

6A-(START-STOP).
SWITCH S.P.S.T.

1

(FUEL PUMP)

TERMINAL BLOCK

1

M4 SHAKEPROOF

1

WASHER

M4-0.7 HEX NUT

1

DECAL, CB RATING 30A.
IM66G, IM72G
DECAL, CB RATING 25A.
IM52G
CLAMP, CABLE

1

M5 FLAT WASHER

1

M5x 10 LONG TAPTITE

1

BUSHING

1

DECAL, CUSTOMER CONN.

1

BOOT, BATTERY CABLE

1

— 19-

PART NO.

TEM

1 73112B

74962E

2

74962B

74962G
3 70155
4 70108

56893

5

74961

6
7 47227

37398

8

73131

9

10 66476
11 72310
12 70125
13 73374
14 74947
15 89473

16 91306

77091

17

QTY. DESCRIPTION

1 CARBURETOR ASSEMBLY

ITEM PART NO. QTY.

18 31879 4 FLATWASHER-NO. 4
1 SPRING, GOVERNOR-(IM5.2) 19 22159 4
1

SPRING, GOVERNOR-(IM6.6) 20

1

SPRING, GOVERNOR-(IM7.2) 21 72536

1

LEVER, GOVERNOR

1

ROD, GOVERNOR TO CARS.

5 SCREW (CRIMPTITE)

N0.10-24x1/2" 25 47662T

1

BRACKET, GOV. ADJUSTER 26

1

SCREW, GOV. ADJUSTER

1

NUT, HEX LOCK (NYLON)

1

BRCKT., AIR CLNR. SUPPORT
2 SCREW, HEX-M6-1.00 x 12MM
2

SCREW, HEX-M6-1.00 x 25MM

1

SPRING, ANTI-LASH

1

BRACKET, CHOKE SUPPORT

1

ROD, CHOKE CONTROL

1

BI-METAL ASSEMBLY, CHOKE

1

SOLENOID, CHOKE

1

HAIRPIN, COTTER-.0901

89870

22

87770

23

74946

81378 1
81378A 1 DECAL, AIR CLEANER-(IM6.6)
81378B
A2603 1

27 75252 1 KIT, CARBURETOR
28 73130 1

29 40173
30

66829 2
31 75944 1
32 70594

33

77075 1

•20 —

DESCRIPTION

LOCKWASHER-NO. 4

SOLENOID FUEL SHUT-OFF

1

SCREW, PAN HD. MACH.

4

NO. 4-40 X 1/4"
1 LINE, FUEL-5/16" ID.
1 LINK, CHOKE

HOSE-FUEL, 4.5" LG

1

DECAL, AIR CLEANER-(IM5.2)

DECAL, AIR CLEANER-(IM7.2)

1

DECAL, AIR CLEANER-(IM7.2 3PH).

OVERHAUL-NOT SHOWN

FLYWHEEL ASSEMBLY

CLAMP, HOSE (SCREW TYPE)

2

ALUMINUM RIVET-3MM
BRACKET, GOVERNOR SPRING
CAPSCREW, HEX HD.

2

M6-1.0 X 93 LG, WANASHER
COVER, CHOKE COIL

_____________

Drawing No. 79216 ~ ~~ ■

EXPLODED VIEW — V-TWIN ENGINE PARTS

— 21 —

64—@

EXPLODED VIEW — V-TWIN ENGINE PARTS

Drawing No. 79216

-51

■k 76

*78
*77

57

/

101

92^

-39
'73

♦REQUIRES SPECIAL TOOLS TO BtSTALL

SEE REPAIR IRSTRUCnOR UAMJAL

21 722"

63-

^85

81^

|i

---

r

f—ip'--

1

i

III

'82

-86

60—©

59

-38

-62

— 22 —

EXPLODED VIEW — V-TWIN ENGINE PARTS

Drawing No. 79216

ITEM

10
11
12 69336
13
14 67888 2
15 72334
16
17
18 67878
19

20
21 69327

22
23
24
25
26 69317
27 67816
28
29
30
31 70530
32 72358
33 69379 2
34 67895 2

35

PART NO.

1 69331

2 69333

67805

3

79234

4

79235

5 ,
6 70169

7 69332 2

72301 1

8
9 72315

70190
70596

69325 8

75247 1
67924 1

75248 2
75249 2

75250 2
75251 2
72346
69316 2

69320
70513
70584 4

70594 2

QTY.

DESCRIPTION ITEM

1

CYLINDER ASSEMBLY

1

SLEEVE BEARING-30 DIA.

1

OIL SEAL-30 DIAMETER 37

1

CYLINDER HEAD 38 68554
ASSEM.-NO. 1

1

CYLINDER HEAD
ASSEM.-NO. 2

4

SEALING WASHER
GASKET-CYLINDER HD. 43 75253
BREATHER ASSEMBLY

1 .

GASKET, BREATHER

1

SCREW, BREATHER 45 75254

1

TUBE, BREATHER

1

GASKET, OIL SUMP 47
BOLT, CYLINDER HEAD 48
PLUG, OIL DRAIN-3/8" NPT

1

CRANKSHAFT ASSM. 74
OIL SUMP ASSEMBLY
OIL SEAL-35 DIAMETER

9

BOLT, OIL SUMP 77
PISTON ASSM.-STANDARD
RING SET- PISTON

-STANDARD

4

LOCKING RING, PISTON
PISTON PIN-STANDARD
CONNECTING ROD ASSM.

4

BOLT, CONNECTING ROD
EXHAUST VALVE 84

2

INTAKE VALVE

4

VALVE SPRING 85 67156

4

RETAINER, VALVE SPRING

4

KEEPER, VALVE 86 69341

TAPPET, VALVE

1

CAMSHAFT ASSEMBLY

1

INTAKE MANIFOLD
GASKET, CARB. MNTG.

GASKET, INTAKE

MANIFOLD
BOLT, CARB. MNTG.

PART NO.

36 67158

68574

39 68573
40 70506

70554

41
42 70568

44 67885

70535

46

75255
75256

73 68572

75272
75 70122
76 67910

67911
78 67813
79 75268
80

75270

70592

81
82 73123

83 70593

72300

87

80011

70597

88
89 69358
90 67920
91 69328

70547

92

QTY.

DESCRIPTION

4 BOLT, INTAKE

MANIFOLD MNT.

1

PIPE-PLUG, 1/8" NPT

1

SEAL, GOV. SHAFT

1

0-RING, OIL PUMP

1

0-RING, OIL GALLEY

1

SPACER, CARBURETOR
4 STUD, ROCKER ARM
4

SEAL, WASHER

-VALVE COVER

4

NUT, NYLOK-M6
4

SCREW, VALVE ADJUST

1 SCREEN, OIL
1 STARTER MOTOR
2 BOLT, STARTER MOTOR

SCREW, OIL PUMP

2
2 TERMINAL, SPARK PLUG

SEAL, VALVE STEM

2
2 SEAT, INTAKE VALVE

SEAT, EXHAUST VALVE

2

VALVE, GUIDE

4

1 RETAINER AND PIN

1 ROLL PIN
1 AIR CLEANER BASE
1 AIR FILTER

(FLAME RETARDENT)
COVER, AIR CLEANER

1

SCREW, AIR CLEANER

1

COVER
SCREW, AIR CLEANER

2

BASE
1 PRE-FILTER
1 SPRING. BRUSH SET

TUBE, AIR INLET

1
1 DEFLECTOR-BREATHER

2 GASKET, VALVE COVER

1 ROCKER ARM COVER
1 OIL PUMP ASSEMBLY

■23 —

GENERAC’S 1-YEAR LIMITED WARRANTY

FOR

IM SERIES INDUSTRIAL MOBILE GENERATORS

Generac warrants to the original purchaser that its generators will be free from defects in materials or
workmanship for the period set forth below from date of original purchase. During said warranty period,
Generac will, at its option, repair or replace any part which, upon examination by Generac or Generac
Authorized Distributors and/or Dealers, is found to be defective under normal use and service.

1’YEAR WARRANTY SCHEDULE

1. All IM Series generators used in a industrial vehicle shall be warranted from date of purchase for
a period of a 1 year or 2000 hours of operation, whichever occurs first. All parts, labor, removal and
reinstallation shall be covered during this period.

2. The drive train, belt and pulleys on IM series air-cooled generators shall be warranted against
failure due to defective materials or normal usage for the life of the generator. For the original

owner, this drive train warranty shall include parts and labor plus a $50.00 payment upon return of
the failed belt or pulley parts only.

All warranty expense allowances are subject to the conditions defined in the “PUBLISHED GENER
AC POLICIES AND PROCEDURES” manual.

This warranty does NOT cover;

• Costs of maintenance, installation and startup.

• Failures due to normal wear, accident, misuse, abuse, ngligence or improper installation.

• Products which are modified or altered in a manner not authorized by the manufacturer in writing.

• Incidental, consequential or indirect damages caused by defects in materials or workmanship, or any delay in repair or
replacement of defective parts.

• Failure due to misapplication.

• Telephone, telegraph, teletype or other communications expenses.

• Living or travel expenses of persons performing service.

• Ail transportation/travel expenses.

• Rental equipment used while warranty repairs are being performed.

• Overtime labor.

• Starting batteries, fuses, light bulbs and engine fluids.

This warranty is in lace of all other warranties, express or implied. Specifically, Generac maks no
other warranties as to merchantability or fitness for a particular purpose. Generac’s only liability
shall be the repair or replacement of parts as stated above. In no event shall Generac be liable for
any incidental or consequential damages, even if such damages are a result of Generac’s negli
gence. Buyer agrees to make no claims against Generac based on negligence.

GENERAC CORPORATION

P.O. BOX 8

WAUKESHA, Wl 53187

Tele: [phone] Fax: [phone]

CALIFORNIA EMISSION CONTROL WARRANTY STATEMENT

YOUR WARRANTY RIGHTS AND OBLIGATIONS

The California Air Resources Board ("CARB") and Generac Corporation are pleased to explain the Emission Control System
A/arranty on your new industrial mobile (IM) generator. In California, new utility and lawn and garden equipment engines
Tiust be designed, built and equipped to meet the State's stringent anti-smog standards. Generac Corporation will warrant
:he emission control system on your industrial mobile (IM) generator for the periods of time listed below provided there has
oeen no abuse, neglect, unapproved modification, or improper maintenance of your industrial mobile (IM) generator.

Your emission control system may include parts such as the carburetor, ignition system and exhaust system. Also included
may be the compression release system and other emission-related assemblies.

A/here a warrantable condition exists, Generac Corporation will repair your industrial mobile (IM) generator at no cost to
/ou for diagnosis, parts and labor.

MANUFACTURER'S EMISSION CONTROL SYSTEM WARRANTY COVERAGE:

Emissions control systems on 1995 and later model year utility and lawn and garden equipment engines are warranted for
two years as hereinafter noted. If, during such warranty period, any emission-related part on your engine is defective in

materials or workmanship, the part will be repaired or replaced by Generac Corporation.

OWNER'S WARRANTY RESPONSIBILITIES:

As the industrial mobile (IM) generator owner, you are responsible for the performance of the required maintenance listed
in your owners manual. Generac Corporation recommends that you retain all receipts covering maintenance on your indus
trial mobile (IM) generator, but Generac Corporation will not deny warranty solely due to the lack of receipts or for your
failure to provide written evidence of the performance of all scheduled maintenance.

As the industrial mobile (IM) generator owner, you should, however, be aware that Generac Corporation may deny you war
ranty coverage if your industrial mobile (IM) generator or a part thereof has failed due to abuse, neglect, improper mainte
nance or unapproved modifications.

You are responsible for presenting your industrial mobile (IM) generator to a Generac Corporation Authorized Service
Outlet as soon as a problem exists. The warranty repairs should be completed in a reasonable amount of time, not to exceed
30 days.

Warranty service can be arranged by contacting either a Generac Corporation Authorized Service Outlet or by contacting
Generac Corporation at:

GENERAC CORPORATION PH: [phone]

P.O.BOX 8 FX: [phone]

WAUKESHA, Wl 53187

IMPORTANT NOTE: This warranty statement explains your rights and obligations under the Emission Control System
Warranty'(“ECS Warranty") which is provided to you by Generac Corporation pursuant to California law. See also the
Generac Corporation Limited Warranties for Generac Corporation which is enclosed herewith on a separate sheet and also is

provided to you by Generac Corporation. The ECS Warranty applies only to the emission control system of your new engine.
To the extent that there is any conflict in terms between the ECS Warranty and the Generac Corporation Warranty, the ECS
Warranty shall apply except in any circumstances in which the Generac Corporation Warranty may provide a longer warran
ty period. Both the ECS Warranty and the Generac Corporation Warranty describe important rights and obligations with
respect to your new engine.

.Warranty service can only be performed by a Generac Corporation Authorized Service Outlet. At the time of requesting

warranty service, evidence must be presented of the date of the sale to the original purchaser. The purchaser shall pay any
charges for making service calls and/or for transporting the products to and from the place where the inspection and/or war-

, ranty work is performed. The purchaser shall be responsible for any damage or loss incurred in connection with the trans

portation of any engine or any part(s) thereof submitted for inspection and/or warranty work.
IF YOU HAVE ANY QUESTIONS REGARDING YOUR WARRANTY RIGHTS AND RESPONSIBILITIES, YOU SHOULD CONTACT

GENERAC CORPORATION AT 1-800-222-3136

EMISSION CONTROL SYSTEM WARRANTY

Emission Control System Warranty (“ECS Warranty") for 1995 and Later Model Year Utility and Lawn and Garden Equipment
Engines:

A. Applicability: This warranty shall apply to 1995 and later model year utility and lawn and garden equipment engines. The

ECS Warranty Period ("ECS Warranty Period") shall begin on the date the new engine or equipment is delivered to its origi-.
nal, end-use purchaser and shall continue for 24 consecutive months thereafter.

B. General Emissions Warranty Coverage: Generac Corporation warrants to the original, end-use purchaser of the new engine^

or equipment and to each subsequent purchaser that each of its utility and lawn and garden equipment engines is:

1. Designed, built and equipped so as to conform with all applicable regulations adopted by the Air Resources Board pur
suant to its authority, and

2. Free from defects in materials and workmanship which, at any time during the ECS Warranty Period, will cause a warrant
ed emissions - related part to fail to be identical in all material respects to the part as described in the engine manufac

turer's application for certification.

C. The ECS Warranty only pertains to emissions-related parts on your engine, as follows:

1. Any warranted, emissions-related parts which are not scheduled for replacement as required maintenance in the Owner's
Manual shall be warranted for the ECS Warranty Period. If any such part fails during the ECS Warranty Period, it shall be
repaired or replaced by Generac Corporation according to Subsection (4) below. Any such part repaired or replaced under

the ECS Warranty shall be warranted for any remainder of the ECS Warranty Period.

2. Any warranted, emissions-related part which is scheduled only for regular inspection as specified in the Owner's Manual
shall be warranted for the ECS Warranty Period. A statement in such written instructions to the effect of "repair or
replace as necessary" shall not reduce the ECS Warranty Period. Any such part repaired or replaced under the ECS
Warranty shall be warranted for any remainder of the ECS Warranty Period.

3. Any warranted, emissions-related part which is scheduled for replacement as required maintenance in the Owner's

Manual shall be warranted for the period of time prior to first scheduled replacement point for that part, if the part fails

prior to the first scheduled replacement, the part shall be repaired or replaced by Generac Corporation according to
Subsection (4) below. Any such emissions-related part repaired or replaced under the ECS Warranty shall be warranted
for the remainder of the ECS Warranty Period prior to the first scheduled replacement point for such emissions-related

part.

4. Repair or Replacement of any warranted, emissions-related part under this ECS Warranty shall be performed at no charge
to the owner at a Generac Corporation Authorized Service Outlet.

5. The owner shall not be charged for diagnostic labor which leads to the determination that a part covered by the ECS
Warranty is in fact defective, provided that such diagnostic work is performed at a Generac Corporation Authorized
Service Outlet.

6. Generac Corporation shall be liable for damages to other original engine components or approved modification^ proxi­mately caused by a failure under warranty of any emission-related part covered by the ECS Warranty.

7. Throughout the ECS Warranty Period, Generac shall maintain a supply of warranted emission-related parts sufficient to
meet the expected demand for such emission-related parts.

8. Any Generac Corporation authorized and approved emission-related replacement part may be used in the performance

of any ECS warranty maintenance or repairs and will be provided without charge to the owner. Such use shall not reduce
Generac Corporation ECS warranty obligations.

9. Unapproved add-on modified parts may not be used to modify or repair a Generac Corporation engine. Such use voids

this ECS Warranty and shall be sufficient grounds for disallowing an' ECS Warranty claim. Generac Corporation shall not

be liable hereunder for failures of any warranted parts of a Generac Corporation engine caused by the use of such an

unapproved add-on or modified part.

EMISSION RELATED PARTS INCLUDE THE FOLLOWING:

1. Carburetor assembly and its internal components.
a. Fuel filter

b. Carburetor gaskets

c. Fuel pump (if so equipped)

2. Air cleaner assembly
a. Air filter element
b. Intake pipe/manifold

3. Ignition system including:
a. Spark plug
b. Ignition module

4. Catalytic muffler (if so equipped)
a. Muffler gasket (if so equipped)
b. Exhaust manifold (if so equipped)

5. Crankcase breather assembly and its components,

a. Breather connection tube