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Kohler 100REZG Generator Set

The Kohler 100REZG is a 80 kW (80 kVA) Natural Gas, LP Gas, or Dual Fuel standby generator set powered by a General Motors 8.1L engine. It is available at 480 V, 50 Hz. It holds about 10 L (2.6 gal) of oil and 25.7 L (6.8 gal) of coolant, with a maximum ambient rating of 50 °C. The set produces 71 dBA at 23 m. The same 8.1L engine also powers generator sets from Cummins/Onan, General Motors, SDMO and Taylor Power.

80 kW
Standby
8.1 L
Displacement
10.0 L
Oil capacity
4
Document types

How to read your Kohler serial & model number →

Typical fuel consumption for 80–85 kW Bi-Fuel (NG/LP) generators →

Compare with other 80–85 kW Bi-Fuel (NG/LP) generators →

Service parts for the 100REZG

Grouped by system, with how many of each the parts manual calls for.

Oil system

1 required

Belts

1 required
374176Beltsee priceAmazon

Electrical

1 required
24-XDBatterysee priceeBay

Ignition

1 required
2.270Spark plugfind

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

FuelNatural Gas, LP Gas, or Dual Fuel
Frequency50.0 Hz
Standby power80 kW
Standby kVA80
Controller6000, Decision-Maker 550
Oil capacity10.0 L
AlternatorFast-Response II (FRII)
Voltage options480 V
Coolant capacity25.7 L
Engine jacket water10.0 L
Max ambient50 °C
Sound level71.0 dBA @ 23 m

Engine

General Motors 8.1L
Oil capacity10.0 L
Coolant capacity10.0 L
Displacement8.1 L
AspirationNatural Aspiration
Rated speed1500 rpm

Same engine, other brands

4 brands

The General Motors 8.1L in this set also powers 7 generator sets sold under 4 other brands. Service parts and maintenance intervals for the engine are shared; enclosure, alternator, controller and ratings are not.

BrandModels
SDMOG100, G110, G125U, G130
Cummins/OnanGGLB-5791965
General Motors8.1L Powertrain
Taylor PowerTGR70

Maintenance & consumables

for the General Motors 8.1L
ItemSpecCapacityPart #Interval
Air filter—500 hr
Fuel filter—1000 hr
Oil filterGM16703 Amazon eBay $58.00 NAPA $3.59
Battery1, Crown 24-XD×124-XD eBay
BeltDrive Belt Tensioner374176 Amazon eBay
Coolant29.9 liters—1000 hr
Coolant filter—
Oil7.1 liters—250 hr
Spark plugReplace spark plugs2.27010000 hr buy

Service specifications

60
TypeItemValueUnitCondition
Other10 in. weld flange bolt circle diameter B361.95mm (14.25 in.)
Other10 in. weld flange outside diameter C406.4mm (16.0 in.)
Other10 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other12 in. weld flange bolt circle diameter B431.80mm (17.00 in.)
Other12 in. weld flange outside diameter C482.6mm (19.0 in.)
Other12 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other14 in. weld flange bolt circle diameter B476.25mm (18.75 in.)
Other14 in. weld flange outside diameter C533.4mm (21.0 in.)
Other14 in. weld flange quantity of bolts / bolt hole diameter D12, 28.58mm (1.13 in.)
Other16 in. weld flange bolt circle diameter B539.75mm (21.25 in.)
Other16 in. weld flange outside diameter C596.9mm (23.5 in.)
Other16 in. weld flange quantity of bolts / bolt hole diameter D16, 28.58mm (1.13 in.)
Other18 in. weld flange bolt circle diameter B577.85mm (22.75 in.)
Other18 in. weld flange outside diameter C635.0mm (25.0 in.)
Other18 in. weld flange quantity of bolts / bolt hole diameter D16, 31.75mm (1.25 in.)
Other20 in. weld flange bolt circle diameter B635.00mm (25.00 in.)
Other20 in. weld flange outside diameter C698.5mm (27.5 in.)
Other20 in. weld flange quantity of bolts / bolt hole diameter D20, 31.75mm (1.25 in.)
Other5 in. weld flange bolt circle diameter B215.90mm (8.50 in.)
Other5 in. weld flange outside diameter C241.30mm (9.50 in.)
Other5 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other6 in. weld flange bolt circle diameter B254.0mm (10.0 in.)
Other6 in. weld flange outside diameter C279.4mm (11.0 in.)
Other6 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other8 in. weld flange bolt circle diameter B298.45mm (11.75 in.)
Other8 in. weld flange outside diameter C342.9mm (13.5 in.)
Other8 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
OtherWeld flange angle A (10, 12, 14 in. nominal pipe size)30deg.
OtherWeld flange angle A (16, 18, 20 in. nominal pipe size)22.5deg.
OtherWeld flange angle A (5, 6, 8 in. nominal pipe size)45deg.
Torque1-12 fastener283.0 (209)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque1-8 fastener259.0 (191)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque1/2-13 fastener60.0 (44)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque1/2-20 fastener66.0 (49)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque1/4-20 fastener6.8 (60)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque1/4-28 fastener8.1 (72)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque10-24 fastener2.9 (26)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque10-32 fastener2.9 (26)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque3/4-10 fastener199.0 (147)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque3/4-16 fastener222.0 (164)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque3/8-16 fastener24.0 (18)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque3/8-24 fastener27.0 (20)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque5/16-18 fastener13.6 (120)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque5/16-24 fastener14.9 (132)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque5/8-11 fastener113.0 (83)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque5/8-18 fastener128.0 (94)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque7/16-14 fastener39.0 (29)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque7/16-20 fastener43.0 (32)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque8-32 fastener1.8 (16)Nm (in. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque9/16-12 fastener81.0 (60)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
Torque9/16-18 fastener91.0 (67)Nm (ft. lb.)Assembled into cast iron or steel, Grade 2 or 5
TorqueM10 x 1.25 fastener31.0 (23)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM10 x 1.50 fastener30.0 (22)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM12 x 1.50 fastener56.0 (41)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM12 x 1.75 fastener53.0 (39)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM14 x 1.50 fastener87.0 (64)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM14 x 2.00 fastener83.0 (61)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM16 x 1.50 fastener132.0 (97)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM16 x 2.00 fastener127.0 (94)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8
TorqueM18 x 1.50 fastener189.0 (140)Nm (ft. lb.)Assembled into cast iron or steel, Grade 5.8 or 8.8

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

2
Common Hardware Application installation
  1. Determine entry hole type: round or slotted.
  2. Determine exit hole type: fixed female thread (weld nut), round, or slotted.
  3. For round and slotted exit holes, determine if hardware is greater than 1/2 inch in diameter.
  4. Hardware greater than 1/2 inch in diameter uses a standard nut and SAE washer.
  5. Hardware 1/2 inch or less in diameter can use a properly torqued whiz nut or spiralock nut.
  6. Always use a washer between hardware and a slot.
  7. Always use a washer under a nut.
  8. Use a washer under a bolt when the female thread is fixed (weld nut).
How to Find Part Numbers operation
  1. Locate the generator set nameplate to identify the generator set spec number.
  2. Locate the second nameplate listing accessories to identify installed modules; on some models it is inside the junction box.
  3. Turn to the Specification Number Index; the first column lists generator set spec numbers.
  4. Identify the group most likely to include the service part number.
  5. Find the group variation number at the intersection of the spec number row and group column.
  6. Page forward to locate that group or find the page in the Table of Contents.
  7. Find the part on the illustration and note the item number, or find the part description in the parts list.
  8. Select the part number that corresponds to your group variation using the column on the right side of the parts list table.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
12-LeadAlternator Reconnections diagram ADV-5875B-M (page 16)
4-LeadAlternator Reconnections diagram ADV-5875A-M (page 15)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

How many kW is the Kohler 100REZG?

The Kohler 100REZG is rated 80 kW standby (80.0 kVA).

What engine does the Kohler 100REZG use?

The Kohler 100REZG is powered by the General Motors 8.1L engine.

What kind of fuel does the Kohler 100REZG run on?

The Kohler 100REZG runs on Natural Gas, LP Gas, or Dual Fuel.

How much oil does the Kohler 100REZG take?

The General Motors 8.1L engine in the Kohler 100REZG has an oil capacity of 10.0 liters.

What is the coolant capacity of the Kohler 100REZG?

The Kohler 100REZG cooling system holds 25.7 liters (6.8 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.

How loud is the Kohler 100REZG?

The Kohler 100REZG is rated at 71.0 dBA at 23 m, per the manufacturer specification sheet.

What voltage does the Kohler 100REZG produce?

The Kohler 100REZG is offered in 480 V.

What alternator comes on the Kohler 100REZG?

The Kohler 100REZG uses a Fast-Response II (FRII) alternator.

Which oil filter part number does the Kohler 100REZG take?

The Kohler 100REZG uses oil filter part number GM16703.

Parts

102
Part #DescriptionQtySystem
1052367Engine Oil Supplement LubricantFluid Amazon eBay $19.95
290090Switch, low water temperature1Sensor Amazon eBay
36881696ELEMENT, ENGINE OIL FILTER1Oil filter eBay $25.99
373133Clutch Pilot Bearing Removal Tools RequiredClutch pilot bearing removal tools required Amazon eBay $84.66
374176Drive BeltBelt Amazon eBay
375105Clutch Pilot Bearing Removal (C/K/C3500HD)Clutch pilot bearing removal Amazon eBay
416EManifold Absolute Pressure (MAP) sensor circuit - CKT 416ESensor eBay $132.10 FridayParts $12.00 SinoCMP $729.00
470515Repair Instructions - Draining Fluids and Oil Filter RemovalRepair instructions Amazon eBay $7.65
470572Engine Flywheel Removal (C/K/C3500HD with AT MT1)Engine flywheel removal Amazon eBay
470576Engine Flywheel Removal (Medium Duty with MT)Engine flywheel removal Amazon eBay $110.99
470599Engine Flywheel Housing Removal (Medium Duty with AT)Engine flywheel housing removal Amazon eBay
470627Clutch Pilot Bearing Removal (Medium Duty)Clutch pilot bearing removal Amazon eBay
470639Oil Level Indicator and Tube Removal (C/K/C3500HD)Oil level indicator and tube removal Amazon eBay $90.00
470666Oil Level Indicator and Tube Removal (G)Oil level indicator and tube removal Amazon eBay
638592Flywheel Housing Adapter, Medium Duty with Manual TransmissionFlywheel housing adapter Amazon eBay $695.00
638596Cylinder Head and ComponentsCylinder head and components Amazon eBay
638602Intake Manifold and ComponentsIntake manifold and components Amazon eBay $4840.00
638608Engine Crankshaft and ComponentsEngine crankshaft and components Amazon eBay
638616Lower Engine Block and ComponentsLower engine block and components Amazon eBay
640013Crankshaft Balancer Removal Tools RequiredCrankshaft balancer removal tools required Amazon eBay $12.99
640014Crankshaft Balancer Removal StepsCrankshaft balancer removal steps Amazon eBay $11.08
677764Engine Identification NumberEngine identification number Amazon eBay $94.90
677814Engine Flywheel Removal (C3500HD with AT M74)Engine flywheel removal Amazon eBay
679414Engine Flywheel Removal (C/K with MT)Engine flywheel removal Amazon eBay $19.58
85400737OUTER AIR FILTER1Air filter eBay
85400786INNER AIR FILTER1Air filter eBay $27.98
85400893INJECTOR6Injector eBay
85400976FUEL FILTER1Fuel filter eBay $15.99 KuduParts $18.00
85401099PRESSURE SWITCH1Sensor eBay
85401131ROCKER COVER GASKET1Gasket eBay
85401164TEMPERATURE SWITCH1Sensor eBay
85401180THERMOSTAT1Thermostat eBay
85401206THERMOSTAT SEAL1Seal eBay
85401289RADIATOR TOP HOSE1Hose eBay
85401313WATER PUMP1Pump eBay
85402451VOLTAGE REGULATOR1Avr eBay
85403434MANUAL PUMP1Pump eBay
85403525FUEL FILTER SEPARATOR1Fuel filter eBay
85403632MAGNETIC SPEED SENSOR L75 3/4UNF1Sensor eBay
85403756BATTERY ELECTROLYTE2Fluid eBay
85403921AIR FILTER HEAVY DUTY1Air filter eBay
85404572LEVEL SENSOR1Sensor eBay
85404598PRESSURE SWITCH 00/10 BAR1Sensor eBay
85404606TEMPERATURE SENSOR 40/120°1Sensor eBay
85410108AIR RESTRICTION INDICATOR1Sensor eBay
85425460BELT1Belt eBay
85426005RADIATOR BOTTOM HOSE1Hose eBay
85431120FUEL FILTER1Fuel filter eBay
9985770MAP Sensor Seal LubricantFluid Amazon eBay
GM16430Sealer, oil pan / Sealant, LoctiteFluid Amazon
GM16576Seal, oil pan drain plug1Seal Amazon eBay
GM16703Filter, oil1Oil filter Amazon eBay $58.00 NAPA $3.59
GM18888Sealer, crankshaft rear main bearingFluid Amazon
GM18906Sensor, knock2Sensor Amazon
GM18933Sealer, camshaft bearing hole plugFluid Amazon
GM18934Grease, heavy duty multipurposeFluid Amazon
GM18951Gasket, engine front cover, also part of 761Gasket Amazon
GM18952Sensor, crankshaft position (includes 123)1Sensor Amazon
GM18963Gasket, water pump2Gasket Amazon
GM18964Gasket, engine coolant crossover2Gasket Amazon
GM18967Hose, therm bypass includes hose clamps1Hose Amazon
GM18971Seal, crankshaft rear oil1Seal Amazon
GM18972Seal, crankshaft front oil1Seal Amazon
GM18990Pump, oil with screen1Pump Amazon
GM19004Sensor, camshaft position (2001 GM engines / GM model year 2003 and older)1Sensor Amazon
GM19009Gasket, oil pan1Gasket Amazon
GM19027Pump kit, water (incl. 31, 82, 83, 85, 105)1Pump Amazon
GM24739Sensor, camshaft position (2002 and 2003 GM engines)1Sensor Amazon
GM42165Thermostat, block heater 49C--60C (120F--140F)1Thermostat Amazon
GM51539Sensor, camshaft position (2004-- GM engines)1Sensor Amazon
GM75077Sensor, Cm/Shf Posn (GM model year 2004 and newer)Sensor Amazon
MEFI4309Map Sensor 1Sensor eBay
MEFI4310Knock Sensor (KS) 1Sensor eBay
MEFI4313Heated Oxygen (HO2) Sensor 1Sensor eBay
NGE012014Charge Air Cooler BoltsBolt Amazon eBay
S105Ignition Coil (cylinders #8)1Ignition coil eBay FridayParts $7.90
S107Ignition Coil (cylinders #1, #3 & #5)1Ignition coil Amazon eBay $150.00 FridayParts $84.50
TJ14R-P15Denso plug typeSpark plug eBay
0333-0588-03Coolant heater, 1500W, 120V1Service part / kit eBay
1051396Engine Oil Supplement LubricantService part / kit Amazon eBay $19.95
1052942Crankshaft Rear Bearing Cap SealantService part / kit Amazon eBay $9.99
12377901Camshaft Rear Bearing Hole Plug SealantService part / kit Amazon eBay
22307Test Light Amperage Draw TestService part / kit eBay
24-XDBattery, Crown 24-XD1Service part / kit eBay
39200DVOM J 39200Service part / kit eBay
85401081COOLANT HEATER RESISTANCE 1000W 240V1Service part / kit eBay
85403616ELECTRONIC ACTUATOR1Service part / kit eBay
85403731STARTING BATTERY 12V 100Ah 450A1Service part / kit eBay
85404267AIR HEATER RESISTANCE 1200W 12V1Service part / kit eBay
854095303 WAY FUEL VALVE2Service part / kit eBay
85410249AIR SHUT OFF VALVE D511Service part / kit eBay
85425585SURGE SUPPRESSOR1Service part / kit eBay
85425593DIODE BRIDGE1Service part / kit eBay
85425908BEARING1Service part / kit eBay
85425932DRIVE DISC1Service part / kit eBay
85426260ELECTRONIC GOVERNOR 12VCC1Service part / kit eBay
85500635WATER RADIATOR1Service part / kit eBay
C109Ignition Control Ground1Service part / kit eBay $390.04
C110Ignition Control Ground1Service part / kit eBay $44.99 FridayParts $14.90
GM23005-5Coolant heater, Hotstart, 1500W, 120V1Service part / kit eBay
GM28341Battery charger, 120V, 1.6A1Service part / kit eBay
LG199Home Maintenance KitService part / kit Amazon eBay

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents

Spec sheet (Kohler)Spec sheet — 100REZG (Kohler)Reference (Kohler)Reference — G6-39 0918AZ (Kohler)Parts manual — tp6667 (Kohler)Service manual — sb735 (Kohler)Service manual — tp6712 (Kohler)

This page was generated from the 7 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.

Full service, cheapest listings

Priced items from this model's own parts manual.

Oil filter GM16703$3.59
1 priced item$3.59