Kohler 8.5RMY User manual

Industrial Generator Sets
Models:
8.5RMY
11RMY
Controllers:
Relay
TP-5867 11/02d
Service

Engine exhaust from this product contains chemicals
known to the State of California to cause cancer, birth
defects, or other reproductive harm.
WARNING
California Proposition 65
Product Identification Information
Product identification numbers determine service parts.
Record the product identification numbers in the spaces
below immediately after unpacking the products so that
the numbers are readily available for future reference.
Record field-installed kit numbers after installing the
kits.
Generator Set Identification Numbers
Record the product identification numbers from the
generator set nameplate(s).
Model Designation
Specification Number
Serial Number
Accessory Number Accessory Description
Controller Identification
Record the controller description from the generator set
operation manual, spec sheet, or sales invoice.
Controller Description
Engine Identification
Record the product identification information from the
engine nameplate.
Manufacturer
Model Designation
Serial Number

Table of Contents
TP-5867 11/02 Table of Contents
Product Identification Information Inside front cover............................................
Safety Precautions and Instructions I........................................................
Introduction i...............................................................................
Service Assistance ii........................................................................
Section 1 Specifications 1...................................................................
1.1 Introduction 1..........................................................
1.2 Controller Features 1....................................................
1.3 Alternator 1............................................................
1.4 Generator Set Specifications 2............................................
1.5 Engine 2...............................................................
1.6 Service Views 3........................................................
Section 2 Scheduled Maintenance 7..........................................................
2.1 Service Schedule 8.....................................................
2.2 Lubrication System 8....................................................
2.2.1 Low Oil Pressure Shutdown 8....................................
2.2.2 Oil Level Check 8...............................................
2.2.3 Engine Oil Recommendation 8....................................
2.2.4 Oil Change Procedure 10.........................................
2.3 Spark Plugs 11..........................................................
2.4 Air Cleaner Element and Precleaner 11.....................................
2.5 Cooling System 12.......................................................
2.6 Exhaust System 13......................................................
2.7 Battery 13...............................................................
2.7.1 Cleaning the Battery 14...........................................
2.7.2 Checking Battery Electrolyte Level 14...............................
2.7.3 Checking Electrolyte Specific Gravity 14............................
2.8 Storage Procedure 15....................................................
2.8.1 Lubricating System 15............................................
2.8.2 Fuel System 15..................................................
2.8.3 Internal Engine Components (Gas/Gasoline-Fueled Engines) 16.......
2.8.4 Exterior 16......................................................
2.8.5 Battery 16.......................................................
Section 3 Troubleshooting 17.................................................................
Section 4 Controller Troubleshooting 23.......................................................
4.1 Relay Controller 23.......................................................
4.2 Sequence of Operation 24................................................
4.2.1 Starting Sequence 26.............................................
4.2.2 Running Sequence 26............................................
4.2.3 Stopping Sequence 26............................................
4.2.4 Fault Shutdown 26...............................................
4.3 Controller Circuit Board 26................................................
4.4 Cyclic Cranking 28.......................................................
4.4.1 Adjustment 28...................................................
4.4.2 Testing 28.......................................................
Section 5 Generator/Relay Controller Troubleshooting 31.......................................
Section 6 Component Testing and Adjustment 35..............................................
6.1 Theory of Operation, 1-Phase Generator Sets with Power Boost IIIE Voltage
Regulator 35............................................................
6.2 Generator Troubleshooting 35.............................................
6.3 Voltage Regulator 36.....................................................
6.3.1 Voltage Regulator Test 37.........................................

Table of Contents, continued
TP-5867 11/02Table of Contents
6.3.2 Voltage Regulator Adjustment 38...................................
6.4 Main Field (Rotor) 39.....................................................
6.4.1 Rotor Continuity and Resistance Tests 39...........................
6.4.2 Slip Rings 40....................................................
6.5 Stator 40................................................................
6.6 Brushes 42..............................................................
6.7 Engine/Generator Components 43.........................................
6.7.1 Gas Valve Operation Check 43....................................
6.7.2 Voltage Checks 43...............................................
6.7.3 Continuity Checks 43.............................................
6.8 Fault Shutdown Test Procedure 45.........................................
6.8.1 Controller Fault Shutdown Functions 45.............................
6.8.2 Fault Shutdown Switches 45.......................................
6.9 Electronic Governor 46...................................................
6.9.1 Operation 46....................................................
6.9.2 Initial Checks and Operation Test 46................................
6.9.3 Hunting/Surging 47...............................................
6.9.4 Governor System Operation Test 47................................
6.9.5 Frequency Adjustment 49.........................................
6.9.6 Overspeed Verification and Adjustment 50...........................
6.10 Speed Sensor 51........................................................
6.11 Fuel Systems 53.........................................................
6.11.1 Gas Piping 53...................................................
6.11.2 Fuel Solenoid Valve 53...........................................
6.11.3 Fuel Regulators 53...............................................
6.11.4 Fuel Conversion, Single-Fuel Models 54............................
6.11.5 Fuel Metering Valve Adjustment 54.................................
6.11.6 Fuel Conversion, Multi-Fuel Systems 56............................
Section 7 Generator Reconnection 59.........................................................
7.1 Voltage Reconnection 59.................................................
7.2 Four-Lead (Single-Phase) Generator Sets 60................................
7.2.1 Factory Connections, 110/220 Volts 50 Hz or 120/240 Volts 60 Hz 60...
7.2.2 Reconnection Options 60.........................................
110 and 120 Volt Configurations 60.................................
220 and 240 Volt Configuration 61..................................
Section 8 Disassembly/Reassembly 63........................................................
8.1 Disassembly 63..........................................................
8.2 Reassembly 66..........................................................
Section 9 Wiring Diagrams 71................................................................
9.1 General 71..............................................................
9.2 Wiring Diagram Cross-Reference 71........................................
9.3 Controller Wiring Diagrams Reference 71...................................
Appendix A Abbreviations A-1..................................................................
Appendix B Common Hardware Application Guidelines A-3........................................
Appendix C General Torque Specifications A-4...................................................
Appendix D Common Hardware Identification A-5.................................................
Appendix E Common Hardware List A-6.........................................................

TP-5867 11/02 ISafety Precautions and Instructions
Safety Precautions and Instructions
IMPORTANT SAFETY
INSTRUCTIONS. Electromechanical
equipment, including generator sets,
transfer switches, switchgear, and
accessories, can cause bodily harm
and pose life-threatening danger when
improperly installed, operated, or
maintained. To prevent accidents be
aware of potential dangers and act
safely. Read and follow all safety
precautions and instructions. SAVE
THESE INSTRUCTIONS.
This manual has several types of safety
precautions and instructions: Danger,
Warning, Caution, and Notice.
DANGER
Danger indicates the presence of a
hazard that will cause severe
personal injury, death,orsubstantial
property damage.
WARNING
Warning indicates the presence of a
hazard that can cause severe
personal injury, death, or substantial
property damage.
CAUTION
Caution indicates the presence of a
hazard that will or can cause minor
personal injury or property damage.
NOTICE
Notice communicates installation,
operation, or maintenance information
that is safety related but not hazard
related.
Safety decals affixed to the equipment
in prominent places alert the operator
or service technician to potential
hazards and explain how to act safely.
The decals are shown throughout this
publication to improve operator
recognition. Replace missing or
damaged decals.
Accidental Starting
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working on the generator set.
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
WARNING
Disabling the generator set.
Accidental starting can cause
severe injury or death. Before
working on the generator set or
connected equipment, disable the
generator set as follows: (1) Move the
generator set master switch to the OFF
position. (2) Disconnect the power to
the battery charger. (3) Remove the
battery cables, negative (--) lead first.
Reconnect the negative (--) lead last
when reconnecting the battery. Follow
these precautions to prevent starting of
the generator set by an automatic
transfer switch, remote start/stop
switch, or engine start command from a
remote computer.
Battery
Sulfuric acid in batteries.
Can cause severe injury or death.
Wear protective goggles and
clothing. Battery acid may cause
blindness and burn skin.
WARNING
Explosion.
Can cause severe injury or death.
Relays in the battery charger
cause arcs or sparks.
Locate the battery in a well-ventilated
area. Isolate the battery charger from
explosive fumes.
WARNING
Battery electrolyte is a diluted
sulfuric acid. Battery acid can cause
severe injury or death. Battery acid
can cause blindness and burn skin.
Always wear splashproof safety
goggles, rubber gloves, and boots
when servicing the battery. Do not
open a sealed battery or mutilate the
battery case. If battery acid splashes in
the eyes or on the skin, immediately
flush the affected area for 15 minutes
with large quantities of clean water.
Seek immediate medical aid in the case
of eye contact. Never add acid to a
battery after placing the battery in
service, as this may result in hazardous
spattering of battery acid.
Battery gases. Explosion can cause
severe injury or death. Battery gases
can cause an explosion. Do not smoke
or permit flames or sparks to occur near
a battery at any time, particularly when
it is charging. Do not dispose of a
battery in a fire. To prevent burns and
sparks that could cause an explosion,
avoid touching the battery terminals
with tools or other metal objects.
Remove all jewelry before servicing the
equipment. Discharge static electricity
from your body before touching
batteries by first touching a grounded
metal surface away from the battery. To
avoid sparks, do not disturb the battery
charger connections while the battery
is charging. Always turn the battery
charger off before disconnecting the
battery connections. Ventilate the
compartments containing batteries to
prevent accumulation of explosive
gases.

TP-5867 11/02II Safety Precautions and Instructions
Engine Backfire/Flash
Fire
Fire.
Can cause severe injury or death.
Do not smoke or permit flames or
sparks near fuels or the fuel system.
WARNING
Servicing the fuel system. A flash
fire can cause severe injury or death.
Do not smoke or permit flames or
sparks near the carburetor, fuel line,
fuel filter, fuel pump, or other potential
sources of spilled fuels or fuel vapors.
Catch fuels in an approved container
when removing the fuel line or
carburetor.
Servicing the air cleaner. A sudden
backfire can cause severe injury or
death. Do not operate the generator
set with the air cleaner removed.
Exhaust System
Carbon monoxide.
Can cause severe nausea,
fainting, or death.
The exhaust system must be
leakproof and routinely inspected.
WARNING
Generator set operation. Carbon
monoxide can cause severe nausea,
fainting, or death. Carbon monoxide
is an odorless, colorless, tasteless,
nonirritating gas that can cause death if
inhaled for even a short time. Avoid
breathing exhaust fumes when working
on or near the generator set. Never
operate the generator set inside a
building unless the exhaust gas is
piped safely outside. Never operate
the generator set where exhaust gas
could accumulate and seep back inside
a potentially occupied building.
Carbon monoxide symptoms.
Carbon monoxide can cause severe
nausea, fainting, or death. Carbon
monoxide is a poisonous gas present in
exhaust gases. Carbon monoxide
poisoning symptoms include but are
not limited to the following:
DLight-headedness, dizziness
DPhysical fatigue, weakness in
joints and muscles
DSleepiness, mental fatigue,
inability to concentrate
or speak clearly, blurred vision
DStomachache, vomiting, nausea
If experiencing any of these symptoms
and carbon monoxide poisoning is
possible, seek fresh air immediately
and remain active. Do not sit, lie down,
or fall asleep. Alert others to the
possibility of carbon monoxide
poisoning. Seek medical attention if
the condition of affected persons does
not improve within minutes of breathing
fresh air.
Fuel System
Explosive fuel vapors.
Can cause severe injury or death.
Use extreme care when handling,
storing, and using fuels.
WARNING
The fuel system. Explosive fuel
vapors can cause severe injury or
death. Vaporized fuels are highly
explosive. Use extreme care when
handling and storing fuels. Store fuels
inawell-ventilatedareaawayfrom
spark-producing equipment and out of
the reach of children. Never add fuel to
the tank while the engine is running
because spilled fuel may ignite on
contact with hot parts or from sparks.
Do not smoke or permit flames or
sparks to occur near sources of spilled
fuel or fuel vapors. Keep the fuel lines
and connections tight and in good
condition. Do not replace flexible fuel
lines with rigid lines. Use flexible
sections to avoid fuel line breakage
caused by vibration. Do not operate the
generator set in the presence of fuel
leaks, fuel accumulation, or sparks.
Repair fuel systems before resuming
generator set operation.
Explosive fuel vapors can cause
severe injury or death. Take
additional precautions when using the
following fuels:
Propane (LP)—Adequate ventilation
is mandatory. Because propane is
heavier than air, install propane gas
detectors low in a room. Inspect the
detectors per the manufacturer’s
instructions.
Natural Gas—Adequate ventilation is
mandatory. Because natural gas rises,
install natural gas detectors high in a
room. Inspect the detectors per the
manufacturer’s instructions.
Gas fuel leaks. Explosive fuel
vapors can cause severe injury or
death. Fuel leakage can cause an
explosion. Check the LP vapor gas or
natural gas fuel system for leakage by
using a soap and water solution with
the fuel system test pressurized to
6--8 ounces per square inch
(10--14 inches water column). Do not
use a soap solution containing either
ammonia or chlorine because both
prevent bubble formation. A successful
test depends on the ability of the
solution to bubble.
LP liquid withdrawal fuel leaks.
Explosive fuel vapors can cause
severe injury or death. Fuel leakage
can cause an explosion. Check the LP
liquid withdrawal gas fuel system for
leakage by using a soap and water
solution with the fuel system test
pressurized to at least 90 psi
(621 kPa). Do not use a soap solution
containing either ammonia or chlorine
because both prevent bubble
formation. A successful test depends
on the ability of the solution to bubble.

TP-5867 11/02 IIISafety Precautions and Instructions
Hazardous Noise
Hazardous noise.
Can cause hearing loss.
Never operate the generator set
without a muffler or with a faulty
exhaust system.
CAUTION
Hazardous Voltage/
Electrical Shock
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
areinplace.
Moving rotor.
WARNING
Hazardous voltage.
Backfeed to the utility system can
cause property damage, severe
injury, or death.
If the generator set is used for
standby power, install an automatic
transfer switch to prevent inadvertent
interconnection of standby and
normal sources of supply.
WARNING
Grounding electrical equipment.
Hazardous voltage can cause
severe injury or death. Electrocution
is possible whenever electricity is
present. Open the main circuit
breakers of all power sources before
servicing the equipment. Configure the
installation to electrically ground the
generator set, transfer switch, and
related equipment and electrical
circuits to comply with applicable codes
and standards. Never contact
electrical leads or appliances when
standing in water or on wet ground
because these conditions increase the
risk of electrocution.
High voltage test. Hazardous
voltage can cause severe injury or
death. Follow the instructions of the
test equipment manufacturer when
performing high-voltage tests on the
rotor or stator. An improper test
procedure can damage equipment or
lead to generator set failure.
Installing the battery charger.
Hazardous voltage can cause
severe injury or death. An
ungrounded battery charger may
cause electrical shock. Connect the
battery charger enclosure to the ground
of a permanent wiring system. As an
alternative, install an equipment
grounding conductor with circuit
conductors and connect it to the
equipment grounding terminal or the
lead on the battery charger. Install the
battery charger as prescribed in the
equipment manual. Install the battery
charger in compliance with local codes
and ordinances.
Connecting the battery and the
battery charger. Hazardous voltage
can cause severe injury or death.
Reconnect the battery correctly,
positive to positive and negative to
negative, to avoid electrical shock and
damage to the battery charger and
battery(ies). Have a qualified
electrician install the battery(ies).
Short circuits. Hazardous
voltage/current can cause severe
injury or death. Short circuits can
cause bodily injury and/or equipment
damage.Do not contact electrical
connections with tools or jewelry while
making adjustments or repairs.
Remove all jewelry before servicing the
equipment.
Testing the voltage regulator.
Hazardous voltage can cause
severe injury or death. High voltage
is present at the voltage regulator heat
sink. To prevent electrical shock do not
touch the voltage regulator heat sink
when testing the voltage regulator.
(PowerBoostt, PowerBoosttIII, and
PowerBoosttV voltage regulator
models only)
Electrical backfeed to the utility.
Hazardous backfeed voltage can
cause severe injury or death. Install
a transfer switch in standby power
installations to prevent the connection
of standby and other sources of power.
Electrical backfeed into a utility
electrical system can cause severe
injury or death to utility personnel
working on power lines.
Heavy Equipment
Unbalanced weight.
Improper lifting can cause severe
injury or death and equipment
damage.
Do not use lifting eyes.
Lift the generator set using lifting bars
inserted through the lifting holes on
the skid.
WARNING
Hot Parts
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until
it cools.
WARNING
Servicing the generator. Hot parts
can cause severe injury or death.
Avoid touching the generator set field
or exciter armature. When shorted, the
generator set field and exciter armature
become hot enough to cause severe
burns.
Servicing the exhaust system. Hot
parts can cause severe injury or
death. Do not touch hot engine parts.
The engine and exhaust system
components become extremely hot
during operation.

TP-5867 11/02IV Safety Precautions and Instructions
Moving Parts
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
areinplace.
Moving rotor.
WARNING
Rotating parts.
Can cause severe injury or death.
Operate the generator set only when
all guards, screens, and covers are in
place.
WARNING
Tightening the hardware. Flying
projectiles can cause severe injury
or death. Loose hardware can cause
the hardware or pulley to release from
the generator set engine and can cause
personal injury. Retorque all
crankshaft and rotor hardware after
servicing. Do not loosen the crankshaft
hardware or rotor thrubolt when making
adjustments or servicing the generator
set. Rotate the crankshaft manually in
a clockwise direction only. Turning the
crankshaft bolt or rotor thrubolt
counterclockwise can loosen the
hardware.
Servicing the generator set when it
is operating. Exposed moving parts
can cause severe injury or death.
Keep hands, feet, hair, clothing, and
test leads away from the belts and
pulleys when the generator set is
running. Replace guards, screens, and
covers before operating the generator
set.
Notice
NOTICE
This generator set has been
rewired from its nameplate voltage
to
246242
NOTICE
Voltage reconnection. Affix a notice
to the generator set after reconnecting
the set to a voltage different from the
voltage on the nameplate. Order
voltage reconnection decal 246242
from an authorized service
distributor/dealer.
NOTICE
Hardware damage. The engine and
generator set may use both American
Standard and metric hardware. Use
the correct size tools to prevent
rounding of the bolt heads and nuts.
NOTICE
When replacing hardware, do not
substitute with inferior grade
hardware. Screws and nuts are
available in different hardness ratings.
To indicate hardness, American
Standard hardware uses a series of
markings, and metric hardware uses a
numeric system. Check the markings
on the bolt heads and nuts for
identification.
NOTICE
Canadian installations only.For
standby service connect the output of
the generator set to a suitably rated
transfer switch in accordance with
Canadian Electrical Code, Part 1.

TP-5867 11/02 iIntroduction
Introduction
This manual provides troubleshooting and repair
instructions for the generator set models listed on the
front cover. Refer to the engine service manual for
generator set engine service information.
This manual may also be used for similar models not
listed on the front cover.
Information in this publication represents data available
at the time of print. Kohler Co. reserves the right to
change this publication and the products represented
without notice and without any obligation or liability
whatsoever.
Read this manual and carefully follow all procedures
and safety precautions to ensure proper equipment
operation and to avoid bodily injury. Read and follow the
Safety Precautions and Instructions section at the
beginning of this manual. Keep this manual with the
equipment for future reference.
The equipment service requirements are very important
to safe and efficient operation. Inspect the parts often
and perform required service at the prescribed intervals.
Maintenance work must be performed by appropriately
skilled and suitably trained maintenance personnel
familiar with generator set operation and service.
Routine Service Parts
The following tables contain part numbers for
recommended spare parts. Contact your Kohler
generator distributor/dealer for a complete list of service
parts for your generator set or for models or spec
numbers not listed here.
Part Description Part Number
Air cleaner element 24 083 08
Precleaner element 24 083 02
Oil filter 12 050 01
Spark plug 12 132 02
Voltage regulator fuse, 10 amp 223316
Controller fuse, 10 amp 223316
Figure 1-1 Recommended Spare Parts
Generator
S
t
S
Circuit Breaker Part Number
Model
Set Spec
Number X-506-43 X-506-38 358384 GM24928
PA--195007
PA-195016 X
PA-195017
8.5RMY PA-195021
PA-195025 X
GM16902-GA1
GM24829-GA1 X
PA--195008
PA--195018 X
PA--195019
11RMY PA--195022
PA--195026
X
GM16902-GA2
X
GM24829-GA2
Figure 1-2 Circuit Breakers

TP-5867 11/02ii Service Assistance
Service Assistance
For professional advice on generator power
requirements and conscientious service, please contact
your nearest Kohler distributor or dealer.
DConsult the Yellow Pages under the heading
Generators—Electric
DVisit the Kohler Power Systems website at
KohlerPowerSystems.com
DLook at the labels and stickers on your Kohler product
or review the appropriate literature or documents
included with the product
DCall toll free in the US and Canada 1-800-544-2444
DOutside the US and Canada, call the nearest regional
office
Africa, Europe, Middle East
London Regional Office
Langley, Slough, England
Phone: [phone]
Fax: [phone]
Asia Pacific
Power Systems Asia Pacific Regional Office
Singapore, Republic of Singapore
Phone: [phone]
Fax: [phone]
China
North China Regional Office, Beijing
Phone: [phone]
(86) 10 6518 7951
(86) 10 6518 7952
Fax: [phone]
East China Regional Office, Shanghai
Phone: [phone]
Fax: [phone]
India, Bangladesh, Sri Lanka
India Regional Office
Bangalore, India
Phone: [phone]
(91) 80 3366231
Fax: [phone]
Japan, Korea
North Asia Regional Office
Tokyo, Japan
Phone: [phone]
Fax: [phone]
Latin America
Latin America Regional Office
Lakeland, Florida, USA
Phone: [phone]
Fax: [phone]
X:in:008:001a

TP-5867 11/02 1Section 1 Specifications
Section 1 Specifications
1.1 Introduction
The spec sheets for each generator set provide specific
generator and engine information. Refer to the
respective spec sheet for data not supplied in this
manual. Consult the generator set installation manual,
engine operation manual, and engine service manual
for additional specifications.
1.2 Controller Features
The generator set is equipped with a relay controller.
For a specific description of the controller, see
Section 2, Operation, in the operation manual.
Controller features include the following:
DFault shutdowns:
DOvercrank
DOverspeed
DPressure, low oil
DHigh engine temperature
DRunning time meter
DSwitches and standard features:
DMaster switch, RUN/RESET-OFF/AUTO
DCranking, cyclic
DLine circuit breaker
DCommon fault lamp (on some controllers)
1.3 Alternator
The generator is equipped with Kohler’s PowerBoostt
voltage regulation system, which provides instant
response to load changes.
PowerBoosttis a unique system that ensures reliable
motor starting and consistent voltage levels.
PowerBoosttutilizes a voltage monitoring system that
employs a winding independent of the field to monitor
and stabilize voltage.
See Figure 1-1 for alternator specifications.
Alternator Specification 8.5/11RMY
Frequency Hz 50/60
Phase Single-Phase
Number of leads 4
Excitation method Static Excited
Voltage regulator type PowerBoosttIIIE
Coupling type Direct
Thrubolt torque, Nm ( ft. lb.) 38 (28)
Overbolt torque, Nm (in. lb.) 7 (60)
Insulation (rotor and stator) Epoxy varnish, vacuum
impregnated
Units built before 7/1/02 Class 155
Units built after 7/1/02 Class 180
Winding material Copper
Bearing, number and type 1, replaceable ball
Circuit protection
Controller 10 amps
Voltage regulator 10 amps
Generator AC output Dependent on voltage
configuration
Rotor resistance, ohms, cold 4.0
Stator resistance, ohms,* cold
Leads: 1-2, 3-4 0.07
33-44 0.07
55-33 0.70
Stator output voltage with
separately excited rotor using
12-volt battery, minimum
Leads: 1-2, 3-4 132V
33-44 132V
55-33 145V
Rotor field voltage/current
readings at rated output
voltage, hot
No load 8V/2.5 amps
Full load 47V/7.4 amps
Brush length, new 19.05 mm (0.75 in.)
* Most ohmmeters do not give accurate readings when
measuring less than 1 ohm. The stator can be considered
good if a low resistance reading (continuity) is obtained and
there is no evidence of shorted windings (discoloration). Do
not confuse a low resistance reading with a reading indicating a
shorted winding.
Figure 1-1 Alternator Specifications

TP-5867 11/022 Section 1 Specifications
1.4 Generator Set Specifications
See Figure 1-2 for generator set specifications. Consult
the generator set nameplate for specific generator set
ratings.
1.5 Engine
The 8.5/11RMY generator sets are equipped with
four-cycle, twin cylinder, air-cooled Kohler engines.
Some of the engine features include:
DOne-side serviceability of air cleaner, carburetor, oil
fill, dipstick, and oil drain.
DEfficient overhead valve design and full pressure
lubrication for maximum power, torque, and reliability
under all operating conditions.
DElectronic governor to ensure AC power output is
maintained at desired frequency.
DOverspeed shutdown to prevent governed frequency
from exceeding 70 Hz.
DLow oil pressure cutout to prevent failure.
DDependable, maintenance free electronic ignition.
DParts subject to the most wear and tear made from
precision formulated cast iron.
DHydraulic valve adjusters to eliminate the need for
valve adjustments.
DMulti-fuel models with field-convertible fuel systems
that allow fuel changeover from natural gas to LP
vapor (and vice-versa) while maintaining CARB
certification. (This applies only to models with
specification numbers starting with the letters GM.)
See Figure 1-3 for engine specifications.
For engine service information not covered in this
manual, see the Engine Service Manual.
Model Voltage Phase Hz Generator Model
Standby kW/kVA
Nat. Gas
Standby kW/kVA
LP Gas
8.5RMY 120/240 1 60 2F4 7.0/7.0 8.5/8.5
8.5RMY 110/220 1 50 2F4 6.3/6.3 7.5/7.5
11RMY 120/240 1 60 2F4 9.5/9.5 11.0/11.0
11RMY 110/220 1 50 2F4 8.5/8.5 9.6/9.6
RATINGS: Standby ratings are continuous for the duration of any power outage. No overload capacity is specified at this rating. All single-phase units are rated at 1.0 power factor. DERA-
TION: Maximum altitude before generator deration, ft. (m): 1000 (305). Altitude deration factor, % per 1000 ft. (305 m): 3.0. Maximum intake air temperature before generator deration, _F
(_C): 60 (16). Temperature deration factor, % per 10_F(5.5_C): 2.0. Standard reference conditions are 25_C(77_F) and 100 kPa (29.5 in. Hg) total barometric pressure per ISO 85-28-1.
GENERAL GUIDELINES FOR DERATING: Maximum altitude before generator deration, ft. (m): 1000 (305). Altitude deration factor, % per 1000 ft. (305 m): 3.0. Maximum intake air
temperature before generator deration, _F(_C): 60(16). Temperature deration factor, % per 10_F(5.5_C): 2.0.DERATING: ALTITUDE: Derate 4% per 305 m (1000 ft.) elevation above 153 m
(500 ft.). TEMPERATURE: Derate 1% per 5.5_C(10_F) temperature increase above 25_C(77_F). Derate applies to actual conditions at the carburetor inlet. Availability is subject to change
without notice. Kohler Co. reserves the right to change the design or specifications without notice and without any obligation or liability whatsoever. Contact your local Kohler Co. generator
distributor for availability.
Figure 1-2 Generator Set Specifications

TP-5867 11/02 3Section 1 Specifications
Engine Specification 8.5RMY (60 Hz) 11RMY (60 Hz)
Manufacturer Kohler
Model CH20 CH25
Cycle 4
Number of cylinders 2
Compression ratio 8.5:1 9.0:1
Displacement, cc (cu. in.) 624 (38.0) 725 (44.0)
Rated horsepower (propane fuel) 12.3 (16.5) 14.6 (19.6)
Rpm 3600
Bore x stroke, mm (in.) 77 x 67 (3.03 x 2.64) 83 x 67 (3.27 x 2.64)
Valve material Steel/Stelliter
Cylinder block material Aluminum w/cast iron liners
Cylinder head tightening torque, Nm (ft. lb.) 30 (40.7)
Cylinder head material Aluminum
Piston rings 2 compression/1 oil
Crankshaft material Heat treated, Ductile Iron
Main bearings: number, type 2, parent material
Governor Electronic
Lubrication system Full pressure
Oil capacity (w/filter), L (qt.) 1.9 (2.0) 2 (2.1)
Oil pressure, kPa (psi) 172--241 (25--35)
Fuel system LP gas or natural gas
LP/natural gas minimum supply pressure,
in. H2O (oz./in.2)7--11 (4--6)
Battery voltage 12 VDC
Battery ground Negative
Spark plug gap, mm (in.) 0.76 (0.030)
Spark plug tightening torque, Nm (ft. lb.) 24.4/29.8 (18/22)
Ignition system Capacitor Discharge Smart Spark Capacitor Dis-
charge
Starter motor cranking current at 70_F Electric, solenoid shift
Cooling system Air-cooled
Figure 1-3 Engine Specifications
1.6 Service Views
This section includes two generator set service views.
See Figure 1-4 and the descriptions below to determine
which service view applies to your generator set.
Figure 1-5 shows a single-fuel generator set, which can
be identified in two ways:
DSingle-fuel model specification numbers begin with
PA-. See the generator set nameplate for the spec
number.
DSingle-fuel models have the fuel valve shown in
Figure 1-5.
Figure 1-6 shows a multi-fuel generator set, which can
be identified in two ways:
DMulti-fuel model specification numbers begin with
GM. See the generator set nameplate for the spec
number.
DMulti-fuel models have the fuel block shown in
Figure 1-6.
Spec Number
Format Fuel System Service View
PA-xxxxxx Single-fuel Figure 1-5
GMxxxxx Multi-fuel Figure 1-6
Figure 1-4 Service View Identification

TP-5867 11/024 Section 1 Specifications
AUTOOFF
RESET/
RUN
F2 10 AMP
TYPE ABCTYPE ABC
F1 10 AMP
~
ON
OFF
P-358000-C
123 679 11
1617
5
1415
13
19
12
12
18
1. Generator set sound enclosure (weather housing not shown)
2. Muffler
3. Oil check
4. Oil drain hose
5. Oil fill
6. Spark plugs
7. Air cleaner
8. Fuel valve (Do not adjust on emission-certified models.)
9. Controller
10. Nameplate
11. Gas regulator assembly
12. Rodent screens
13. Engine starting battery location
14. Engine oil cooler
15. Engine battery charge regulator
16. Oil drain valve
17. Oil filter
18. Rodent plugs
19. Spark arrestor
84 10
Figure 1-5 Generator Set Service View, Single-Fuel Systems (spec numbers PA-)

TP-5867 11/02 5Section 1 Specifications
123 678 11
1718
5
1516
14
20
13
13
19
10
GM24829A-A
1. Generator set sound enclosure
2. Muffler
3. Oil check
4. Oil drain hose
5. Oil fill
6. Spark plugs
7. Air cleaner
8. Controller
9. Nameplate
10. Multi-fuel block
11. Gas regulator assembly
12. Fuel solenoid valve
13. Rodent screens
14. Engine starting battery location
15. Engine oil cooler
16. Engine battery charge regulator
17. Oil drain valve
18. Oil filter
19. Rodent plugs
20. Spark arrestor
4 9 12
Figure 1-6 Generator Set Service View, Multi-Fuel Systems (spec numbers GM)

TP-5867 11/026 Section 1 Specifications
Notes

TP-5867 11/02 7Section 2 Scheduled Maintenance
Section 2 Scheduled Maintenance
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working on the generator set.
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
WARNING
Disabling the generator set. Accidental starting can
cause severe injury or death. Before working on the
generator set or connected equipment, disable the generator
set as follows: (1) Move the generator set master switch to the
OFF position. (2) Disconnect the power to the battery charger.
(3) Remove the battery cables, negative (--) lead first.
Reconnect the negative (--) lead last when reconnecting the
battery. Follow these precautions to prevent starting of the
generator set by an automatic transfer switch, remote
start/stop switch, or engine start command from a remote
computer.
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until
it cools.
WARNING
Servicing the exhaust system. Hot parts can cause
severe injury or death. Do not touch hot engine parts. The
engine and exhaust system components become extremely
hot during operation.
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
areinplace.
Moving rotor.
WARNING
See the Safety Precautions and Instructions at the
beginning of this manual before attempting to service,
repair, or operate the generator set. Have an authorized
distributor/dealer perform generator set service.
Alternator Service. Under normal operating conditions
the generator set alternator does not require scheduled
service. Refer to the service schedule for items that
require maintenance.
Engine Service. Perform generator set engine service
at the intervals specified by the engine service literature.
Contact an authorized Kohlerrservice distributor/
dealer to obtain engine service literature.
All generator sets have emission-certified engines. The
carburetors on emission-certified engines are not
adjustable.
Generator Set Service. See the Safety Precautions
and Instructions at the beginning of this manual before
attempting to service, repair, or operate the generator
set. Have an authorized Kohlerrservice distributor/
dealer perform all generator service.
If the generator set operates under dusty or dirty
conditions, use dry compressed air to blow dust out of
the generator. With the generator set running, direct the
stream of air in through the cooling slots at the generator
end.
Routine Maintenance. Refer to the following generator
set service schedule, the engine service schedule, and
the hourmeter located on the generator set controller to
determine when to schedule routine maintenance.
Service the generator set more frequently if it is subject
to extreme weather, long operating hours, or dusty or
dirty conditions.
Service Schedule. Perform maintenance on each item
in the service schedule at the designated interval for the
life of the generator set.
Tools. Tools and instruments used to perform some
maintenance items are not generally available to the
generator set owner. Therefore, have service
performed by an authorized distributor/dealer.

TP-5867 11/028 Section 2 Scheduled Maintenance
2.1 Service Schedule
Perform the items listed in the service schedule at the
designated intervals for the life of the generator set. For
example, an item serviced every 100 hours or 3 months
must also be serviced after 200 hours or 6 months,
300 hours or 9 months, etc. Rough operation, lack of
power, and excessive oil use indicate serious generator
set problems.
2.2 Lubrication System
See Section 2.1, Scheduled Maintenance, for oil
change and oil filter replacement intervals. See
Section 1.6, Service Views, for the oil drain, oil check, oil
fill, and oil filter locations.
The engine has a positive pressure lubrication system
and low oil pressure shutdown.
2.2.1 Low Oil Pressure Shutdown
The low oil pressure shutdown feature protects the
engine against internal damage if the oil pressure drops
below preset limits because of oil pump failure or other
malfunction. It does not protect against damage
because of operating with the oil level below the safe
range—it is not a low oil level shutdown.
2.2.2 Oil Level Check
Check the oil level regularly and add oil as needed to
protect against running out of oil. See Figure 2-1 for the
dipstick and oil fill locations. Do not check the oil level
when the generator set is running. Shut down the
generator set and wait several minutes before checking
the oil level.
2.2.3 Engine Oil Recommendation
Use synthetic oil of API (American Petroleum Institute)
Service Class SG or SH. Synthetic oil oxidizes and
thickens less and causes fewer deposits on the engine
intake valves and pistons than other oils.
If nonsynthetic oil is used, select the viscosity based on
the air temperature at the time of operation. See
Figure 2-3.
A-358000A-C
12
1. Oil check dipstick
2. Oil fill
Figure 2-1 Oil Fill and Check
Model L(Qt.)
8.5RMY 1.9 (2.0)
11RMY 2.0 (2.1)
Figure 2-2 Oil Capacity with Filter
°C
°F
-- 3 0
-- 2 0
-- 1 0
0
10
20
30
40
02040
Temperature Range Expected Before Next Oil
Change
32 60 80 100
10W-30
5W-20, 5W-30
-- 2 0
Figure 2-3 Engine Oil Selection

TP-5867 11/02 9Section 2 Scheduled Maintenance
Action
System—Component Visually Inspect Check Change Clean Test Interval
Fuel
Flexible lines and connections X R Weekly
Main tank supply level X Weekly
Fuel piping X Yearly
Lubrication
Oil level D D Weekly
Crankcase breather D D Quarterly
Change oil DYearly or 50 Hrs
Replace filter(s)* DYearly or 50 Hrs
Cooling
Air cleaner to room/enclosure XWeekly
Air ducts, louvers X X Yearly
Exhaust Line
Leakage X X Weekly
Insulation, fire hazards XQuarterly
Flexible connector(s) XSix Months
Hangers and supports X Yearly
DC Electrical System
Battery charger operation, charge rate XMonthly
Recharge after engine start[XMonthly
Remove corrosion, clean and dry battery and rack X X Monthly
Clean and tighten battery terminals X X Quarterly
Tighten DC electrical connections X Six Months
AC Electrical System
General inspection X Weekly
Wire abrasions where subject to motion X X Quarterly
Safety and alarm operation X X Six Months
Tighten control and power wiring connections X Yearly
Wire-cable insulation breakdown X3 Years or 500 Hrs
Engine And Mounting
General inspection DWeekly
Air cleaner service D D Six Months
Ignition components D D Yearly
Valve clearance D3 Years or 500 Hrs.
Bolt torque D D 3 Years or 500 Hrs.
Generator
Compartment condition X X Weekly
Rotor and stator X X Yearly
Measure and record resistance readings of windings with
insulation tester (Megger, with SCR assembly or rectifier
disconnected)
XYearly
Run generator set X Monthly
Remote control X Monthly
Blow dust out of generator* X X 2 Years or 300 Hrs
General Condition Of Equipment
Any condition of vibration, leakage, noise, temperature,
or deterioration X X X Weekly
Interior of equipment room or outdoor weather housing X X Weekly
DFollow procedures and frequencies indicated in the engine manufacturer’s maintenance manual.
If not indicated, follow this service schedule. Some items may not apply to all generator sets.
R Replace as necessary.
XAction
* Service more frequently if operated in dusty areas.
[Consult battery manufacturer’s instructions.
Figure 2-4 Service Schedule

TP-5867 11/0210 Section 2 Scheduled Maintenance
2.2.4 Oil Change Procedure
Whenever possible, drain the oil while it is still warm.
1. Drain the oil.
a. Place the generator set master switch in the
OFF position.
b. Disconnect the power to the battery charger, if
equipped.
c. Disconnect the generator set engine starting
battery, negative (--) lead first.
d. Remove the housing side panel.
e. Remove the oil drain hose from its retaining
clip. See Figure 2-5. Remove the cap from the
oil drain hose and lower the hose into an oil
collection container.
f. Open the oil drain valve on the engine.
g. Allow time for the engine oil to drain completely.
h. Close the oil drain valve.
i. Replace the cap on the oil drain hose. Replace
the oil drain hose in its retaining clip.
A-358000A-C
1
2
3
1. Oil drain hose
2. Oil fill
3. Oil filter
Figure 2-5 Engine Service Side
2. Replace the oil filter.
a. Remove the oil filter by rotating it
counterclockwise with an oil filter wrench.
b. Apply a light coat of clean oil to the rubber seal
of the new oil filter.
c. Install the new oil filter following the instructions
provided with the filter.
Note: Dispose of all waste materials (engine
oil, fuel, filter, etc.) in an environmentally
safe manner.
3. Fill with oil. See Section 2.2.3 for oil selection and
Figure 2-2 for oil capacity.
4. Check for leaks.
a. Check that the generator set master switch is in
the OFF position.
b. Reconnect the generator set engine starting
battery, negative (--) lead last.
c. Reconnect the power to the battery charger, if
equipped.
d. Start the generator set and check for leaks
around the oil filter.
e. Stop the generator set and tighten the oil filter to
stop any leaks.
f. Reinstall the housing side panel.