Kohler KG80 Guide

Models:
KG80, KG80R, KG100,KG125, KG125R,
KG150, KG150R, KG180, KG200
Industrial Generator Set
TP-7173 10/20a
Maintenance

2 TP-7173 10/20
WARNING: This product can expose you to chemicals, including carbon monoxide and
benzene, which are known to the State of California to cause cancer and birth defects or
other reproductive harm. For more information go to www.P65warnings.ca.gov
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 engine nameplate(s).
Model Designation _________________________________________________________
Specification Number _______________________________________________________
Serial Number: ____________________________________________________________
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_______________________________________________________________
Accessory Number
Accessory Description
Accessory Number
Accessory Description

TP-7173 10/20 3
Table of Contents
Safety Precautions and Instructions........................................................................................................................................5
Introduction ..............................................................................................................................................................................11
Service Assistance...................................................................................................................................................................12
Section 1. Service Schedule ...................................................................................................................................13
1.1 Safety Precautions.................................................................................................................................................13
1.2 Generator Set Service............................................................................................................................................14
1.2.1 Alternator Service ....................................................................................................................................14
1.2.2 Engine Service.........................................................................................................................................14
Section 2. Controller Maintenance.........................................................................................................................17
Section 3. ECU Diagnostic Port..............................................................................................................................17
Section 4. Alternator Maintenance.........................................................................................................................19
4.1 Check the Operation ..............................................................................................................................................20
4.2 Check the Ventilation .............................................................................................................................................20
4.3 Check the Windings ...............................................................................................................................................20
4.4 Check the Bearings................................................................................................................................................20
Section 5. Gaseous Fuel Systems..........................................................................................................................21
5.1 Gaseous Fuel System Concept (Single Fuel) ........................................................................................................22
5.1.1 Natural Gas and LPG Conversion............................................................................................................22
5.2 Fuel System Changeover Kits (Dual Fuel).............................................................................................................26
5.2.1 Dual Fuel Reset Box................................................................................................................................27
5.2.2 Dual Fuel Connections.............................................................................................................................29
5.3 Fuel System Maintenance......................................................................................................................................30
Section 6. Lubrication System................................................................................................................................31
6.1 Oil Change.............................................................................................................................................................31
Section 7. Air Cleaner System................................................................................................................................31
7.1 Air Filter Element....................................................................................................................................................31
7.2 Air Cleaner Restrictor Indicator ..............................................................................................................................32
Section 8. Cooling System......................................................................................................................................33
8.1 Coolant Level Check..............................................................................................................................................33
8.2 Cooling System Component Inspection .................................................................................................................34
8.3 Procedure to Drain Cooling System.......................................................................................................................34
8.3.1 Procedure to Drain Cooling System.........................................................................................................34
8.4 Procedure to Flush and Clean Cooling System......................................................................................................34
8.5 Procedure to Refill Cooling System........................................................................................................................35
8.6 Radiator Maintenance............................................................................................................................................35
Section 9. Battery system .......................................................................................................................................37
9.1 Clean Battery .........................................................................................................................................................38
9.2 Electrolyte Level Inspection....................................................................................................................................38
9.3 Specific Gravity Check...........................................................................................................................................39
9.4 Charge Battery.......................................................................................................................................................40
Section 10. Storage Procedure.................................................................................................................................41
10.1 Lubrication System.................................................................................................................................................41
10.2 Cooling System......................................................................................................................................................42
10.3 Exterior...................................................................................................................................................................42
10.4 Alternator................................................................................................................................................................42
10.5 Battery....................................................................................................................................................................43
Appendix A. Abbreviations.........................................................................................................................................45
Appendix B. Common Hardware Application Guidelines ........................................................................................49
Appendix C. Torque Specifications ...........................................................................................................................51
Appendix D. Operating Hours and Service Log........................................................................................................53

4 TP-7173 10/20

TP-7173 10/20 5
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 a hazardous situation which, if not avoided, will result in death or serious injury.
WARNING
WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION
CAUTION indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
NOTICE
NOTICE is used to address practices not related to physical injury.
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
WARNING
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.
Disabling the generator set. Accidental starting can cause severe injury or death. Before working on the generator set or
equipment connected to the set, disable the generator set as follows: (1) Press the generator set off/reset button to shut down
the generator set. (2) Disconnect the power to the battery charger, if equipped. (3) Remove the battery cables, negative (–) lead
first. Reconnect the negative (–) lead last when reconnecting the battery. Follow these precautions to prevent the starting of the
generator set by the remote start/stop switch.

6 TP-7173 10/20
Battery
WARNING
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.
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 acid cleanup. Battery acid can cause severe injury or death. Battery acid is electrically conductive and corrosive.
Add 500 g (1 lb.) of bicarbonate of soda (baking soda) to a container with 4 L (1 gal.) of water and mix the neutralizing solution.
Pour the neutralizing solution on the spilled battery acid and continue to add the neutralizing solution to the spilled battery acid
until all evidence of a chemical reaction (foaming) has ceased. Flush the resulting liquid with water and dry the area.
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.
Battery short circuits. Explosion can cause severe injury or death. Short circuits can cause bodily injury and/or equipment
damage. Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the
equipment. Use tools with insulated handles. Remove the negative (–) lead first when disconnecting the battery. Reconnect the
negative (–) lead last when reconnecting the battery. Never connect the negative (–) battery cable to the positive (+) connection
terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together.

TP-7173 10/20 7
Engine Backfire/Flash Fire
WARNING
Risk of fire.
Can cause severe injury or death.
Do not smoke or permit flames or sparks near fuels or the fuel system.
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.
Combustible materials. A fire can cause severe injury or death. Generator set engine fuels and fuel vapors are flammable
and explosive. Handle these materials carefully to minimize the risk of fire or explosion. Equip the compartment or nearby area
with a fully charged fire extinguisher. Select a fire extinguisher rated ABC or BC for electrical fires or as recommended by the
local fire code or an authorized agency. Train all personnel on fire extinguisher operation and fire prevention procedures.
Combustible materials. A fire can cause severe injury or death. If using generator heaters during storage, remove
combustible materials such as covers from contact with the heater or from areas where heat could potentially cause a fire.
Exhaust System
WARNING
Carbon monoxide.
Can cause severe nausea, fainting, or death.
The exhaust system must be leakproof and routinely inspected.
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 is an odorless, colorless, tasteless, nonirritating gas that can cause
death if inhaled for even a short time. Carbon monoxide poisoning symptoms include but are not limited to the following:
Light-headedness, dizziness
Physical fatigue, weakness in joints and muscles
Sleepiness, mental fatigue, inability to concentrate or speak clearly, blurred vision
Stomachache, 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.

8 TP-7173 10/20
Fuel System
WARNING
Explosive fuel vapors.
Can cause severe injury or death.
Use extreme care when handling, storing, and using fuels.
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 in a well-ventilated area away from 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 (LPG)—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
LPG vapor 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.
Hazardous Noise
CAUTION
Hazardous noise.
Can cause hearing loss.
Never operate the generator set without a muffler or with a faulty exhaust system.
Engine noise. Hazardous noise can cause hearing loss. Generator sets not equipped with sound enclosures can produce
noise levels greater than 105 dBA. Prolonged exposure to noise levels greater than 85 dBA can cause permanent hearing loss.
Wear hearing protection when near an operating generator set.

TP-7173 10/20 9
Hazardous Voltage/Moving Parts
DANGER
Hazardous voltage.
Will cause severe injury or death.
Disconnect all power sources before opening the enclosure.
DANGER
Hazardous voltage. Moving parts.
Will cause severe injury or death.
Operate the generator set only when all guards and electrical enclosures are in place.
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.
Grounding electrical equipment. Hazardous voltage will cause severe injury or death. Electrocution is possible whenever
electricity is present. Ensure you comply with all applicable codes and standards. Electrically ground the generator set, transfer
switch, and related equipment and electrical circuits. Turn off the main circuit breakers of all power sources before servicing the
equipment. 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 will 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.
Connecting the battery and the battery charger. Hazardous voltage will 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 will 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.
Engine block heater. Hazardous voltage will cause severe injury or death. The engine block heater can cause electrical
shock. Remove the engine block heater plug from the electrical outlet before working on the block heater electrical connections.
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.
Testing live electrical circuits. Hazardous voltage or current will cause severe injury or death. Have trained and qualified
personnel take diagnostic measurements of live circuits. Use adequately rated test equipment with electrically insulated probes
and follow the instructions of the test equipment manufacturer when performing voltage tests. Observe the following precautions
when performing voltage tests: (1) Remove all jewelry. (2) Stand on a dry, approved electrically insulated mat. (3) Do not touch
the enclosure or components inside the enclosure. (4) Be prepared for the system to operate automatically. (600 volts and under)

10 TP-7173 10/20
WARNING
Airborne particles.
Can cause severe injury or blindness.
Wear protective goggles and clothing when using power tools, hand tools, or
compressed air.
Servicing the generator set when it is operating. Exposed moving parts will 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.
Heavy Equipment
WARNING
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.
Hot Parts
WARNING
Hot coolant and steam.
Can cause severe injury or death.
Before removing the pressure cap, stop the generator set and allow it to cool. Then loosen
the pressure cap to relieve pressure. Fill system before starting unit.
WARNING
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until it cools.
Servicing the alternator. Hot parts can cause severe injury or death. Avoid touching the alternator field or exciter armature.
When shorted, the alternator 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-7173 10/20 11
Introduction
This manual provides the maintenance schedule and general maintenance procedures for the Kohler generator set models listed
on the front cover. For engine or alternator related maintenance schedules and procedures, refer to the engine or alternator
operation manuals. Refer to the Appendix, Operating Hours Service Log, for a means to document maintenance.
Note:
Have maintenance work, including battery service, performed by appropriately skilled and suitably trained maintenance
personnel familiar with generator set operation and service.
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.
Abbreviations
This publication makes use of numerous abbreviations. Typically, the word(s) are spelled out along with the abbreviation in
parentheses when shown for the first time in a section. Refer to the Abbreviations section in the Appendices for abbreviation
definitions.
Related Literature
Manual Description
Literature Part No.
KG6208 Engine Operation Manual
TP-7095
KG10V08T Engine Operation and Maintenance Manual
TP-7172
Engine Diagnostic and Troubleshooting Manual
TP-7097
Alternator Service Manual, FRX
TP-6783
Alternator Service Manual, FRII
TP-6353
APM402 Controller Operation Manual
TP-6694
APM603 Controller Operation Manual
TP-7165
Generator Set Installation Manual
TP-5700
Wiring Diagram, Ind (KG40-KG125)
TP-7112
Wiring Diagrams, Resi (KG80R-KG125R)
TP-7130
Wiring Diagrams, Ind (KG150, KG180, KG200)
TP-7174
Wiring Diagrams, Resi (KG150R)
TP-7175
Figure 1 Related Literature

12 TP-7173 10/20
Service Assistance
For professional advice and conscientious service, please
contact your nearest Kohler distributor or dealer.
Visit the Kohler Co. website at KOHLERPower.com.
Look at the labels and decals on your Kohler product
or review the appropriate literature or documents
included with the product.
Call toll free in the US and Canada 1-800-544-2444.
Outside the US and Canada, call the nearest
regional office.
Headquarters Europe, Middle East, Africa (EMEA)
Kohler EMEA Headquarters
Netherlands B.V.
Kristallaan 1
4761 ZC Zevenbergen
The Netherlands
Phone: [phone]
Fax: [phone]
Asia Pacific
Kohler Asia Pacific Headquarters
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]

TP-7173 10/20 13
Section 1. Service Schedule
1.1 Safety Precautions
WARNING
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.
Disabling the generator set. Accidental starting can cause severe injury or death. Before working on the generator set or
equipment connected to the set, disable the generator set as follows: (1) Press the generator set off/reset button to shut down
the generator set. (2) Disconnect the power to the battery charger, if equipped. (3) Remove the battery cables, negative (–) lead
first. Reconnect the negative (–) lead last when reconnecting the battery. Follow these precautions to prevent the starting of the
generator set by the remote start/stop switch.
Testing live electrical circuits. Hazardous voltage or current will cause severe injury or death. Have trained and qualified
personnel take diagnostic measurements of live circuits. Use adequately rated test equipment with electrically insulated probes
and follow the instructions of the test equipment manufacturer when performing voltage tests. Observe the following precautions
when performing voltage tests: (1) Remove all jewelry. (2) Stand on a dry, approved electrically insulated mat. (3) Do not touch
the enclosure or components inside the enclosure. (4) Be prepared for the system to operate automatically. (600 volts and under)
Grounding electrical equipment. Hazardous voltage will cause severe injury or death. Electrocution is possible whenever
electricity is present. Ensure you comply with all applicable codes and standards. Electrically ground the generator set and
related equipment and electrical circuits. Turn off the main circuit breakers of all power sources before servicing the equipment.
Never contact electrical leads or appliances when standing in water or on wet ground because these conditions increase the
risk of electrocution.
Short circuits. Hazardous voltage/current will 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.
WARNING
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until it cools.
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.
Servicing the alternator. Hot parts can cause severe injury or death. Avoid touching the alternator field or exciter armature.
When shorted, the alternator field and exciter armature become hot enough to cause severe burns.

14 TP-7173 10/20
DANGER
Hazardous voltage. Moving parts.
Will cause severe injury or death.
Operate the generator set only when all guards and electrical enclosures are in place.
Servicing the generator set when it is operating. Exposed moving parts will 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.
1.2 Generator Set Service
The prestart checklist in the controller operation manual lists main areas of the generator set that require attention. Some
procedures may also require using the generator set service manual or engine service manual.
Note:
Have maintenance work, including battery service, performed by appropriately skilled and suitably trained maintenance
personnel familiar with generator set operation and service.
Kohler recommends the use of Kohler Genuine oil, filters, and coolant for maintenance and service.
1.2.1 Alternator Service
Under normal operating conditions, the generator set’s alternator requires no routine service.
When operating the generator set under dusty or dirty conditions, use dry compressed air to blow dust out of the alternator while
the generator set is running. Direct the stream of air through openings in the generator set end bracket.
Refer to the alternator maintenance manual (listed in Related Literature) for typical engine maintenance procedures and
maintenance intervals.
1.2.2 Engine Service
Perform engine service at the intervals specified in the engine operation manual. Contact an authorized Kohler distributor/dealer
to obtain engine literature. Refer to the engine operation manual (listed in Related Literature) for typical engine maintenance
procedures and maintenance intervals such as:
Break-in service
Checking or changing the engine oil and oil filter(s)
Replacing the air filter
Valve lash adjustment

TP-7173 10/20 15
System—Component
Action
Interval
Visually Inspect
Check
Change
Clean
Test
Daily
Oil level
⚫
⚫
Daily
Coolant level
⚫
⚫
Daily
Leakage
X
X
Daily
Any condition of vibration, leakage, noise, temperature,
or deterioration
X
X
X
Daily
Clean and tighten battery terminals
X
X
Daily
Weekly
Flexible lines and connections
X
R
Weekly
Air cleaner to room/enclosure
X
Weekly
Block heater operation
X
Weekly
Flexible hoses and connectors
X
X
Weekly
Water pump(s)
⚫
Weekly
Drain condensate trap
X
Weekly
Controller lamp test
X
R
Weekly
General Inspection
X
Weekly
Compartment condition
X
X
Weekly
Ensure that system is set for automatic operation
X
Weekly
Interior of equipment room or outdoor weather housing
X
X
Weekly
Monthly
Fan and alternator belts
⚫
⚫
R
Monthly
Battery charger operation, charge rate
X
Monthly
Battery electrolyte level
X
Monthly
Battery specific gravity, charge state
X
Monthly
Recharge after engine start
X
Monthly
Remove corrosion, clean and dry battery and rack
X
X
Monthly
Circuit breakers, fuses (Do not break manufacturer’s
seals or internally inspect.)
X
X
R
X
X
Monthly
Remote control
X
Monthly
Run generator set
X
Monthly
Quarterly
Crankcase breather
⚫
⚫
Quarterly
Insulation, fire hazards
X
Quarterly
Wire abrasions where subject to motion
X
X
Quarterly
Six Months
Safety and alarm operation
X
X
Six Months
Coolant temperature protection level
⚫
Six Months
Flexible connector(s)
X
Six Months
Tighten DC electrical connections
X
Six Months
⚫Follow 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.
X Action.
* Service more frequently if operated in dusty areas.
Note: For the Voltage-sensing device/relay adjustment, do not break manufacturer’s seals or internally inspect these devices.

16 TP-7173 10/20
Service Schedule, continued
System—Component
Action
Interval
Visually Inspect
Check
Change
Clean
Test
Yearly
Tighten control and power wiring connections
X
Yearly
Air ducts, louvers
X
X
Yearly
Fuel piping
X
Yearly
Louver motors and controls
X
X
X
Yearly
Radiator exterior
X
X
Yearly
Water supply to the heat exchanger
X
Yearly
Excessive back pressure
X
Yearly
Hangers and supports
X
Yearly
Battery load testing
X
Yearly
Two Years
APM603 RTC battery
R
When indicated by the
controller, 2–10 Years
Three Years
Wire-cable insulation breakdown
X
X
3 Years or
500 Hrs.
Refer to Engine Operation Manual
General engine inspection
⚫
Refer to engine
operation manual for
service intervals and
instructions.
Air cleaner service
⚫
⚫
Ignition components
⚫
⚫
Bolt torque
⚫
⚫
Change oil
⚫
Replace filter(s)*
⚫
Coolant
⚫
Tightness of the oil cooler and charge air cooler couplers.
X
X
Refer to Alternator Operation Manual
General alternator inspection
X
Refer to alternator
operation manual for
service intervals and
instructions
Rotor and stator
X
X
Bearing condition
X
X
R
Exciter
X
X
X
Blow dust out of alternator*
X
⚫
Measure and record resistance readings of windings with
insulation tester (Megger®, with SCR assembly or rectifier
disconnected)
X
⚫Follow 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.
X Action.
* Service more frequently if operated in dusty areas.
Note: For the Voltage-sensing device/relay adjustment, do not break manufacturer’s seals or internally inspect these devices.
Megger®is a registered trademark of Biddle Instruments.

TP-7173 10/20 17
Section 2. Controller Maintenance
APM402
The APM402 controller does not use a Real Time Clock (RTC) battery.
APM603
The APM603 controller uses a CR1220 internal battery to preserve the time, date, and generator set events. If battery power is
low, an alarm, “Replace Clock Battery,”appears on the controller. The Real Time Clock (RTC) battery has an expected lifespan
of ten years when the controller is powered by an engine battery or two years when the controller is not powered by an engine
battery. Have an authorized Kohler service representative service the controller.
Section 3. ECU Diagnostic Port
KG80-KG200 generator sets have a diagnostic port located on the junction box. Use the following for general informational
purposes only. Contact an authorized service distributor/dealer for service or diagnostic equipment.
Note:
For diagnostic and troubleshooting purposes, the ECM/ECU can be powered ON and OFF with the following methods:
The engine ECM/ECU is typically powered ON and OFF with SiteTech™. See the SiteTech™Software Manual for
details.
With the APM402 controller, the operator can also power the ECM/ECU ON and OFF through the controller menus.
See the controller operation manual for details.
With the APM603 controller, the operator can also power the ECU ON and OFF through the controller menus. The
operator password is required. See the controller operation manual for details.
The engine ECM/ECU can also be powered ON by cranking the engine.
Figure 2 ECU Diagnostic Port, Typical
Diagnostic port
ADV-9082

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TP-7173 10/20 19
Section 4. Alternator Maintenance
This section covers alternator maintenance for several different types of alternators. Refer to the instructions that correspond to
the relevant alternator models.
Refer to the generator set specification sheet for alternator models.
Have an authorized distributor/dealer perform service.
WARNING
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.
Disabling the generator set. Accidental starting can cause severe injury or death. Before working on the generator set or
equipment connected to the set, disable the generator set as follows: (1) Press the generator set off/reset button to shut down
the generator set. (2) Disconnect the power to the battery charger, if equipped. (3) Remove the battery cables, negative (–) lead
first. Reconnect the negative (–) lead last when reconnecting the battery. Follow these precautions to prevent the starting of the
generator set by the remote start/stop switch.
Testing live electrical circuits. Hazardous voltage or current will cause severe injury or death. Have trained and qualified
personnel take diagnostic measurements of live circuits. Use adequately rated test equipment with electrically insulated probes
and follow the instructions of the test equipment manufacturer when performing voltage tests. Observe the following precautions
when performing voltage tests: (1) Remove all jewelry. (2) Stand on a dry, approved electrically insulated mat. (3) Do not touch
the enclosure or components inside the enclosure. (4) Be prepared for the system to operate automatically. (600 volts and under)
Grounding electrical equipment. Hazardous voltage will cause severe injury or death. Electrocution is possible whenever
electricity is present. Ensure you comply with all applicable codes and standards. Electrically ground the generator set and
related equipment and electrical circuits. Turn off the main circuit breakers of all power sources before servicing the equipment.
Never contact electrical leads or appliances when standing in water or on wet ground because these conditions increase the
risk of electrocution.
Short circuits. Hazardous voltage/current will 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.
WARNING
Hot engine and exhaust system.
Can cause severe injury or death.
Do not work on the generator set until it cools.
Servicing the alternator. Hot parts can cause severe injury or death. Avoid touching the alternator field or exciter armature.
When shorted, the alternator field and exciter armature become hot enough to cause severe burns.
DANGER
Hazardous voltage. Moving parts.
Will cause severe injury or death.
Operate the generator set only when all guards and electrical enclosures are in place.
Servicing the generator set when it is operating. Exposed moving parts will 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.

20 TP-7173 10/20
4.1 Check the Operation
Check the operation at regular intervals (no abnormal noise or vibration).
Check the tightness of all nuts and bolts. Pay particular attention to the electrical connections.
4.2 Check the Ventilation
Ensure that air flow is not reduced by partial blocking of the air inlet and discharge grids by mud, fiber, grease, etc.
Check for corrosion or abrasion on the air outlet grids.
4.3 Check the Windings
Have an authorized distributor/dealer perform service. Refer to the appropriate alternator service manual. See the Related
Literature.
When operating the generator set under dusty or dirty conditions, use dry compressed air to blow dust out of the alternator while
the generator set is running. Direct the stream of air through openings in the generator set end bracket.
4.4 Check the Bearings
Have an authorized service distributor/dealer perform service.
Replace the end bracket bearing every 10,000 hours of operation. Service the bearing more frequently if the annual inspection
indicates excessive rotor end play or bearing damage. The sealed end bracket bearing requires no additional lubrication.