Service parts for the 125RZG
Grouped by system, with how many of each the parts manual calls for.
Oil system
1 required1.836Oil filterfind
Belts
1 requiredElectrical
1 requiredIgnition
1 required2.270Spark plugfind
Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | LP Gas or Natural Gas |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 125 kW |
| Standby kVA | 95 |
| Prime power | 90 kW |
| Controller | Decision-Maker 550; Decision-Maker 3+ 16-Light |
| Oil capacity | 8.0 L |
| Alternator | 4-Pole, Rotating-Field (Fast-Response III WF / Fast-Response II PM) |
| Voltage options | 208 V |
| Phase | 3 |
| Rated current | 385 A |
| Power factor | 1 |
| Battery group | 24-XD |
| Battery cranking | 630 CCA |
| Battery voltage | 12 DC V |
| Battery quantity | 1 |
| Coolant capacity | 24.2 L |
| Engine jacket water | 10.0 L |
| Max ambient | 50 (122 F) °C |
| Dimensions (L×W×H) | 2400×1040×1484 mm |
| Wet weight | 1134 kg |
Engine
| Oil capacity | 10.0 L |
|---|---|
| Coolant capacity | 10.0 L |
| Displacement | 8.1 L |
| Aspiration | Natural Aspiration |
| Rated speed | 1500 rpm |
Same engine, other brands
4 brandsThe 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.
| Brand | Models |
|---|---|
| SDMO | G100, G110, G125U, G130 |
| Cummins/Onan | GGLB-5791965 |
| General Motors | 8.1L Powertrain |
| Taylor Power | TGR70 |
Maintenance & consumables
for the General Motors 8.1L| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | 500 hr | |||
| Fuel filter | — | 1000 hr | |||
| Oil filter | Replace oil filter | 1.836 | 250 hr | buy | |
| Battery | 1, Crown 24-XD | ×1 | 24-XD | eBay | |
| Belt | Drive Belt Tensioner | 374176 | Amazon eBay | ||
| Coolant | 29.9 liters | — | 1000 hr | ||
| Coolant filter | — | ||||
| Oil | 7.1 liters | — | 250 hr | ||
| Spark plug | Replace spark plugs | 2.270 | 10000 hr | buy |
Service specifications
30| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Other | 10 in. weld flange bolt circle diameter B | 361.95 | mm (14.25 in.) | |
| Other | 10 in. weld flange outside diameter C | 406.4 | mm (16.0 in.) | |
| Other | 10 in. weld flange quantity of bolts / bolt hole diameter D | 12, 25.40 | mm (1.00 in.) | |
| Other | 12 in. weld flange bolt circle diameter B | 431.80 | mm (17.00 in.) | |
| Other | 12 in. weld flange outside diameter C | 482.6 | mm (19.0 in.) | |
| Other | 12 in. weld flange quantity of bolts / bolt hole diameter D | 12, 25.40 | mm (1.00 in.) | |
| Other | 14 in. weld flange bolt circle diameter B | 476.25 | mm (18.75 in.) | |
| Other | 14 in. weld flange outside diameter C | 533.4 | mm (21.0 in.) | |
| Other | 14 in. weld flange quantity of bolts / bolt hole diameter D | 12, 28.58 | mm (1.13 in.) | |
| Other | 16 in. weld flange bolt circle diameter B | 539.75 | mm (21.25 in.) | |
| Other | 16 in. weld flange outside diameter C | 596.9 | mm (23.5 in.) | |
| Other | 16 in. weld flange quantity of bolts / bolt hole diameter D | 16, 28.58 | mm (1.13 in.) | |
| Other | 18 in. weld flange bolt circle diameter B | 577.85 | mm (22.75 in.) | |
| Other | 18 in. weld flange outside diameter C | 635.0 | mm (25.0 in.) | |
| Other | 18 in. weld flange quantity of bolts / bolt hole diameter D | 16, 31.75 | mm (1.25 in.) | |
| Other | 20 in. weld flange bolt circle diameter B | 635.00 | mm (25.00 in.) | |
| Other | 20 in. weld flange outside diameter C | 698.5 | mm (27.5 in.) | |
| Other | 20 in. weld flange quantity of bolts / bolt hole diameter D | 20, 31.75 | mm (1.25 in.) | |
| Other | 5 in. weld flange bolt circle diameter B | 215.90 | mm (8.50 in.) | |
| Other | 5 in. weld flange outside diameter C | 241.30 | mm (9.50 in.) | |
| Other | 5 in. weld flange quantity of bolts / bolt hole diameter D | 8, 22.23 | mm (0.88 in.) | |
| Other | 6 in. weld flange bolt circle diameter B | 254.0 | mm (10.0 in.) | |
| Other | 6 in. weld flange outside diameter C | 279.4 | mm (11.0 in.) | |
| Other | 6 in. weld flange quantity of bolts / bolt hole diameter D | 8, 22.23 | mm (0.88 in.) | |
| Other | 8 in. weld flange bolt circle diameter B | 298.45 | mm (11.75 in.) | |
| Other | 8 in. weld flange outside diameter C | 342.9 | mm (13.5 in.) | |
| Other | 8 in. weld flange quantity of bolts / bolt hole diameter D | 8, 22.23 | mm (0.88 in.) | |
| Other | Weld flange angle A (10, 12, 14 in. nominal pipe size) | 30 | deg. | |
| Other | Weld flange angle A (16, 18, 20 in. nominal pipe size) | 22.5 | deg. | |
| Other | Weld flange angle A (5, 6, 8 in. nominal pipe size) | 45 | deg. |
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
What is the power rating of the Kohler 125RZG?
The Kohler 125RZG is rated 125 kW standby (95.0 kVA).
What engine is in the Kohler 125RZG?
The Kohler 125RZG is powered by the General Motors 8.1L engine.
What kind of fuel does the Kohler 125RZG run on?
The Kohler 125RZG runs on LP Gas or Natural Gas.
How much oil does the Kohler 125RZG take?
The General Motors 8.1L engine in the Kohler 125RZG has an oil capacity of 10.0 liters.
What is the coolant capacity of the Kohler 125RZG?
The Kohler 125RZG cooling system holds 24.2 liters (6.4 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.
What is the continuous rating of the Kohler 125RZG?
The Kohler 125RZG is rated 90 kW prime (90 kVA), against 125 kW standby.
What voltage does the Kohler 125RZG produce?
The Kohler 125RZG is offered in 208 V, 3-phase.
What battery does the Kohler 125RZG use?
The Kohler 125RZG uses 1 battery, 12 DC V each, 630 CCA, group 24-XD, per the manufacturer specification sheet.
What alternator comes on the Kohler 125RZG?
The Kohler 125RZG uses a 4-Pole, Rotating-Field (Fast-Response III WF / Fast-Response II PM) alternator.
What oil filter does the Kohler 125RZG use?
The Kohler 125RZG uses oil filter part number 1.836.
Parts
102| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 1052367 | Engine Oil Supplement Lubricant | Fluid | Amazon eBay $19.95 | |
| 290090 | Switch, low water temperature | 1 | Sensor | Amazon eBay |
| 36881696 | ELEMENT, ENGINE OIL FILTER | 1 | Oil filter | eBay $25.99 |
| 373133 | Clutch Pilot Bearing Removal Tools Required | Clutch pilot bearing removal tools required | Amazon eBay $84.66 | |
| 374176 | Drive Belt | Belt | Amazon eBay | |
| 375105 | Clutch Pilot Bearing Removal (C/K/C3500HD) | Clutch pilot bearing removal | Amazon eBay | |
| 416E | Manifold Absolute Pressure (MAP) sensor circuit - CKT 416E | Sensor | eBay $132.10 FridayParts $12.00 SinoCMP $729.00 | |
| 470515 | Repair Instructions - Draining Fluids and Oil Filter Removal | Repair instructions | Amazon eBay $7.65 | |
| 470572 | Engine Flywheel Removal (C/K/C3500HD with AT MT1) | Engine flywheel removal | Amazon eBay | |
| 470576 | Engine Flywheel Removal (Medium Duty with MT) | Engine flywheel removal | Amazon eBay $110.99 | |
| 470599 | Engine Flywheel Housing Removal (Medium Duty with AT) | Engine flywheel housing removal | Amazon eBay | |
| 470627 | Clutch Pilot Bearing Removal (Medium Duty) | Clutch pilot bearing removal | Amazon eBay | |
| 470639 | Oil Level Indicator and Tube Removal (C/K/C3500HD) | Oil level indicator and tube removal | Amazon eBay $90.00 | |
| 470666 | Oil Level Indicator and Tube Removal (G) | Oil level indicator and tube removal | Amazon eBay | |
| 638592 | Flywheel Housing Adapter, Medium Duty with Manual Transmission | Flywheel housing adapter | Amazon eBay $695.00 | |
| 638596 | Cylinder Head and Components | Cylinder head and components | Amazon eBay | |
| 638602 | Intake Manifold and Components | Intake manifold and components | Amazon eBay $4840.00 | |
| 638608 | Engine Crankshaft and Components | Engine crankshaft and components | Amazon eBay | |
| 638616 | Lower Engine Block and Components | Lower engine block and components | Amazon eBay | |
| 640013 | Crankshaft Balancer Removal Tools Required | Crankshaft balancer removal tools required | Amazon eBay $12.99 | |
| 640014 | Crankshaft Balancer Removal Steps | Crankshaft balancer removal steps | Amazon eBay $11.08 | |
| 677764 | Engine Identification Number | Engine identification number | Amazon eBay $94.90 | |
| 677814 | Engine Flywheel Removal (C3500HD with AT M74) | Engine flywheel removal | Amazon eBay | |
| 679414 | Engine Flywheel Removal (C/K with MT) | Engine flywheel removal | Amazon eBay $19.58 | |
| 85400737 | OUTER AIR FILTER | 1 | Air filter | eBay |
| 85400786 | INNER AIR FILTER | 1 | Air filter | eBay $27.98 |
| 85400893 | INJECTOR | 6 | Injector | eBay |
| 85400976 | FUEL FILTER | 1 | Fuel filter | eBay $15.99 KuduParts $18.00 |
| 85401099 | PRESSURE SWITCH | 1 | Sensor | eBay |
| 85401131 | ROCKER COVER GASKET | 1 | Gasket | eBay |
| 85401164 | TEMPERATURE SWITCH | 1 | Sensor | eBay |
| 85401180 | THERMOSTAT | 1 | Thermostat | eBay |
| 85401206 | THERMOSTAT SEAL | 1 | Seal | eBay |
| 85401289 | RADIATOR TOP HOSE | 1 | Hose | eBay |
| 85401313 | WATER PUMP | 1 | Pump | eBay |
| 85402451 | VOLTAGE REGULATOR | 1 | Avr | eBay |
| 85403434 | MANUAL PUMP | 1 | Pump | eBay |
| 85403525 | FUEL FILTER SEPARATOR | 1 | Fuel filter | eBay |
| 85403632 | MAGNETIC SPEED SENSOR L75 3/4UNF | 1 | Sensor | eBay |
| 85403756 | BATTERY ELECTROLYTE | 2 | Fluid | eBay |
| 85403921 | AIR FILTER HEAVY DUTY | 1 | Air filter | eBay |
| 85404572 | LEVEL SENSOR | 1 | Sensor | eBay |
| 85404598 | PRESSURE SWITCH 00/10 BAR | 1 | Sensor | eBay |
| 85404606 | TEMPERATURE SENSOR 40/120° | 1 | Sensor | eBay |
| 85410108 | AIR RESTRICTION INDICATOR | 1 | Sensor | eBay |
| 85425460 | BELT | 1 | Belt | eBay |
| 85426005 | RADIATOR BOTTOM HOSE | 1 | Hose | eBay |
| 85431120 | FUEL FILTER | 1 | Fuel filter | eBay |
| 9985770 | MAP Sensor Seal Lubricant | Fluid | Amazon eBay | |
| GM16430 | Sealer, oil pan / Sealant, Loctite | Fluid | Amazon | |
| GM16576 | Seal, oil pan drain plug | 1 | Seal | Amazon eBay |
| GM16703 | Filter, oil | 1 | Oil filter | Amazon eBay $58.00 NAPA $3.59 |
| GM18888 | Sealer, crankshaft rear main bearing | Fluid | Amazon | |
| GM18906 | Sensor, knock | 2 | Sensor | Amazon |
| GM18933 | Sealer, camshaft bearing hole plug | Fluid | Amazon | |
| GM18934 | Grease, heavy duty multipurpose | Fluid | Amazon | |
| GM18951 | Gasket, engine front cover, also part of 76 | 1 | Gasket | Amazon |
| GM18952 | Sensor, crankshaft position (includes 123) | 1 | Sensor | Amazon |
| GM18963 | Gasket, water pump | 2 | Gasket | Amazon |
| GM18964 | Gasket, engine coolant crossover | 2 | Gasket | Amazon |
| GM18967 | Hose, therm bypass includes hose clamps | 1 | Hose | Amazon |
| GM18971 | Seal, crankshaft rear oil | 1 | Seal | Amazon |
| GM18972 | Seal, crankshaft front oil | 1 | Seal | Amazon |
| GM18990 | Pump, oil with screen | 1 | Pump | Amazon |
| GM19004 | Sensor, camshaft position (2001 GM engines / GM model year 2003 and older) | 1 | Sensor | Amazon |
| GM19009 | Gasket, oil pan | 1 | Gasket | Amazon |
| GM19027 | Pump kit, water (incl. 31, 82, 83, 85, 105) | 1 | Pump | Amazon |
| GM24739 | Sensor, camshaft position (2002 and 2003 GM engines) | 1 | Sensor | Amazon |
| GM42165 | Thermostat, block heater 49C--60C (120F--140F) | 1 | Thermostat | Amazon |
| GM51539 | Sensor, camshaft position (2004-- GM engines) | 1 | Sensor | Amazon |
| GM75077 | Sensor, Cm/Shf Posn (GM model year 2004 and newer) | Sensor | Amazon | |
| MEFI4309 | Map Sensor 1 | Sensor | eBay | |
| MEFI4310 | Knock Sensor (KS) 1 | Sensor | eBay | |
| MEFI4313 | Heated Oxygen (HO2) Sensor 1 | Sensor | eBay | |
| NGE012014 | Charge Air Cooler Bolts | Bolt | Amazon eBay | |
| S105 | Ignition Coil (cylinders #8) | 1 | Ignition coil | eBay FridayParts $7.90 |
| S107 | Ignition Coil (cylinders #1, #3 & #5) | 1 | Ignition coil | Amazon eBay $150.00 FridayParts $84.50 |
| TJ14R-P15 | Denso plug type | Spark plug | eBay | |
| 0333-0588-03 | Coolant heater, 1500W, 120V | 1 | Service part / kit | eBay |
| 1051396 | Engine Oil Supplement Lubricant | Service part / kit | Amazon eBay $19.95 | |
| 1052942 | Crankshaft Rear Bearing Cap Sealant | Service part / kit | Amazon eBay $9.99 | |
| 12377901 | Camshaft Rear Bearing Hole Plug Sealant | Service part / kit | Amazon eBay | |
| 22307 | Test Light Amperage Draw Test | Service part / kit | eBay | |
| 24-XD | Battery, Crown 24-XD | 1 | Service part / kit | eBay |
| 39200 | DVOM J 39200 | Service part / kit | eBay | |
| 85401081 | COOLANT HEATER RESISTANCE 1000W 240V | 1 | Service part / kit | eBay |
| 85403616 | ELECTRONIC ACTUATOR | 1 | Service part / kit | eBay |
| 85403731 | STARTING BATTERY 12V 100Ah 450A | 1 | Service part / kit | eBay |
| 85404267 | AIR HEATER RESISTANCE 1200W 12V | 1 | Service part / kit | eBay |
| 85409530 | 3 WAY FUEL VALVE | 2 | Service part / kit | eBay |
| 85410249 | AIR SHUT OFF VALVE D51 | 1 | Service part / kit | eBay |
| 85425585 | SURGE SUPPRESSOR | 1 | Service part / kit | eBay |
| 85425593 | DIODE BRIDGE | 1 | Service part / kit | eBay |
| 85425908 | BEARING | 1 | Service part / kit | eBay |
| 85425932 | DRIVE DISC | 1 | Service part / kit | eBay |
| 85426260 | ELECTRONIC GOVERNOR 12VCC | 1 | Service part / kit | eBay |
| 85500635 | WATER RADIATOR | 1 | Service part / kit | eBay |
| C109 | Ignition Control Ground | 1 | Service part / kit | eBay $390.04 |
| C110 | Ignition Control Ground | 1 | Service part / kit | eBay $44.99 FridayParts $14.90 |
| GM23005-5 | Coolant heater, Hotstart, 1500W, 120V | 1 | Service part / kit | eBay |
| GM28341 | Battery charger, 120V, 1.6A | 1 | Service part / kit | eBay |
| LG199 | Home Maintenance Kit | Service 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-125rzg-spec-sheet (Kohler)Reference (Kohler)Reference — G6-39 0918AZ (Kohler)Reference — Kohler-125RZG-SN-2098689-Load-Test-Report-and-Inspection-Checklist (Kohler)Reference — vertical circulator plug in Kohler. G6171 (Kohler)Parts manual — g260412 (Kohler)Service manual — cold weather kit tt1723 (Kohler)Service manual — tp6098 (Kohler)Service manual — tp6274 (Kohler)Service manual — tp6799 (Kohler)Service manual — tt1723 (Kohler)
This page was generated from the 11 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.