Service parts for the 125REOZJG
Grouped by system, with how many of each the parts manual calls for.
Fuel system
3 requiredOil system
1 requiredBelts
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | Diesel |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 125 kW |
| Standby kVA | 156 |
| Prime power | 114 kW |
| Emissions | Tier 3 EPA-Certified |
| Controller | Decision-Maker 3000 |
| Oil capacity | 13.9 L |
| Alternator | 4R12X |
| Voltage options | 120/208 V, 127/220 V, 120/240 V, 139/240 V, 220/380 V, 277/480 V, 347/600 V |
| Phase | 3 |
| Rated current | 188 A |
| Power factor | 0.8 |
| Battery cranking | 800 CCA |
| Battery voltage | 12 V |
| Battery quantity | 1 |
| Coolant capacity | 19.2 L |
| Engine jacket water | 8.5 L |
| Max ambient | 50 °C |
| Dimensions (L×W×H) | 2700×1120×1527 mm |
| Dry weight | 1226 kg |
Engine
| Oil capacity | 13.9 L |
|---|---|
| Coolant capacity | 19.2 L |
| Displacement | 4.5 L |
| Aspiration | Turbocharged, Charge Air-Cooled |
| Rated speed | 1800 rpm |
Filters for the John Deere 4045HF285K
6Engine-mounted filters the filter manufacturers list for this engine family. These come from the engine, not from this generator set’s own parts list, so confirm against your serial number before ordering.
| System | Filter | Description | Cross-references | |
|---|---|---|---|---|
| Oil filter | P551352 | Lube Filter, Spin-On Full Flow | JOHN DEERE DZ118286, JOHN DEERE PMLF3703, NAPA 401062, BALDWIN B40168 | buy |
| Oil filter | P550020 | Lube Filter, Spin-On Full Flow | JOHN DEERE AR58956, JOHN DEERE AT19044T, NAPA 1243, RENAULT VI 0003132302 | KuduParts $23.00 FridayParts $25.67 |
| Fuel filter | P551130 | Fuel Filter, Box | JOHN DEERE AR50041, JOHN DEERE R16951, NAPA 3370, BALDWIN BF909 | KuduParts $37.00 |
| Fuel filter | P550090 | Fuel Filter, In-Line | JOHN DEERE AE20952, JOHN DEERE AT101565, ASV INCORPORATED 0201914, LOESING 025125 | FridayParts $45.66 |
| Fuel / water separator | P551423 | Fuel Filter, Water Separator Spin-On | JOHN DEERE RE503254, JOHN DEERE RE50455, NAPA 3531, NAPA 600091 | KuduParts $18.00 FridayParts $20.00 |
| Fuel / water separator | P551424 | Fuel Filter, Water Separator Spin-On | JOHN DEERE RE503198, JOHN DEERE RE522868, NAPA 3532, NAPA 600094 | KuduParts $16.00 FridayParts $18.50 |
Maintenance & consumables
for the John Deere 4045HF285K| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Dry | — | |||
| Fuel filter | Fuel Filter | GM32809 | Amazon Amazon Amazon Amazon eBay $26.25 NAPA $28.76 | ||
| Fuel filter | Primary | GM50074 | Amazon eBay $70.33 NAPA $38.35 | ||
| Fuel filter | Secondary | GM50006 | Amazon eBay $26.99 NAPA $44.17 | ||
| Oil filter | Cartridge | ×1 | GM32809 | Amazon Amazon Amazon Amazon eBay $26.25 NAPA $28.76 | |
| Belt | 352793 | Amazon |
Compatible filters for the John Deere 4045HF285K — cross-referenced via Donaldson. Options to verify against your serial number, not confirmed for this exact unit.
- Air filter: John Deere AL204809 John Deere AT390262 John Deere AT390261 John Deere AL119839 John Deere AL150285
Service specifications
50| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Gap | Speed sensor air gap | 0.36- 0.71 | mm | |
| 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. | |
| Pressure | Battery equalizer input voltage (24 volts nominal) | 20- 35 | volts | |
| Pressure | Battery equalizer output voltage | (input voltage/2) ±2% | volts | |
| Pressure | Pressure switch 364345 | 483 ±14 | kPa | |
| Resistance | Pressure sender 264390 value A | 240 +17/- 15 | ohms at 0 psi | |
| Resistance | Pressure sender 264390 value B | 153 +12/- 15 | ohms at 25 psi | |
| Resistance | Pressure sender 264390 value C | 33.5 | ohms at 100 psi | |
| Resistance | Pressure sender 365624 value A | 241 ±16 | ohms at 0 psi | |
| Resistance | Pressure sender 365624 value B | 152 ±13 | ohms at 50 psi | |
| Resistance | Pressure sender 365624 value C | 33.5 | ohms at 200 psi | |
| Resistance | Temperature sender 226717 value A | 123.8 +7.2/- 7.8 | ohms at 90.6 C (195 F) | |
| Resistance | Temperature sender 226717 value B | 35.6 +3.4/- 3.6 | ohms at 137.8 C (280 F) | |
| Resistance | Temperature sender 226919 value A | 942 ±22 | ohms at 37.7 C (100 F) | |
| Resistance | Temperature sender 226919 value B | 35 | ohms at 115.6 C (240 F) | |
| Speed | Overspeed shutdown | 70 | Hz | 60 Hz models |
| Temperature | Battery equalizer operating temperature | - 40 to 71 | C (- 40 F to 160 F) | |
| Temperature | Temperature switch 241308 | 107 ±4 | C (225 F ±7 F) | normally open to close on temp. rise |
| Temperature | Temperature switch 290090/GM51705 | 16 ±3 | C (60 F ±5 F) | normally open to close on temp. fall |
| Voltage | Speed sensor voltage, wire 2 (black) & 16 (white) | 3- 6 | volts DC | |
| Voltage | Speed sensor voltage, wire 2 (black) & 24 (red) | 8- 10 | volts DC |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
12Overfrequency Adjustment (Over/Underfrequency Relay, Decision-Maker 3+) adjustment
- Turn the overfrequency adjustment potentiometer fully clockwise (CW).
- Place master switch in RUN to start the generator set.
- Adjust governor per engine operation manual, engine service manual, or governor section of this manual.
- Slowly turn overfrequency potentiometer counterclockwise (CCW) until the LED starts flashing; after about 10 seconds the set shuts down on auxiliary fault.
- Place master switch to OFF/RESET to reset the controller.
- Place master switch to RUN to start the generator set.
- Readjust the governor to the desired frequency as required.
- Place master switch to OFF/RESET to stop the generator set.
Overvoltage Feature Testing and Adjustment (Decision-Maker 3+) adjustment
⚠ Hazardous voltage. Moving parts. Will cause severe injury or death. Operate the generator set only when all guards and electrical enclosures are in place.
⚠ Disconnecting the electrical load. Hazardous voltage will cause severe injury or death.
- Disconnect generator set from load by opening line circuit breaker or disconnecting and taping output leads.
- Determine overvoltage shutdown value based on user requirement; factory setting is 15% above nominal line-to-neutral voltage.
- Remove the controller cover.
- Place master switch in RUN to start the generator set.
- Observe AC voltmeter; turn voltage adjustment potentiometer CW until generator set shuts down.
- If the shutdown point is correct, go to step 12; otherwise continue.
- Turn controller circuit board R42 adjustment potentiometer fully CW.
- Place master switch to OFF/RESET to reset; then to RUN to start.
- Observe AC voltmeter while turning voltage adjustment potentiometer to desired overvoltage shutdown point.
- Turn R42 adjustment potentiometer slowly CCW until the generator set shuts down.
- Turn controller voltage adjustment potentiometer slightly CCW.
- Place master switch OFF/RESET then RUN to start; adjust for correct voltage and phase.
- Place master switch OFF/RESET to stop.
- Disconnect battery negative lead first; reconnect generator set to load; reconnect battery negative lead last.
Reactive Droop Compensator Adjustment Procedure adjustment
Tools: Voltmeter, Wattmeter
- Remove any load; start each generator set with master switch in RUN.
- Set reactive droop compensator rheostat on generator set no. 1 to minimum CCW; record rpm/frequency and voltage at 1/4 load steps to full load.
- Repeat for generator set no. 2.
- Compare readings; adjust voltage within 1 volt and speed within 3 rpm (or 0.1 Hz) at each load step.
- Check droop compensation on each unit with an inductive load 1/2 to full load.
- Adjust rheostat to approximately 4% below rated voltage at full load.
- Repeat for unit no. 2.
Reactive Droop Compensator Alternate Adjustment Procedure adjustment
Tools: Voltmeter
- Turn reactive droop compensator rheostat on generator set no. 1 to minimum setting.
- Remove controller cover; move voltage sensing lead from V7 to V9 at the AC fuse terminal block.
- Remove any load connected to the generator set.
- Start the generator set with master switch in RUN.
- Use controller or remote voltage adjusting potentiometer to fine adjust voltage.
- Apply resistive load (1.0 power factor) until reaching rated current.
- Adjust reactive droop compensator rheostat to achieve a 4% droop in voltage.
- Remove the resistive load and stop the generator set.
- Return voltage sensing lead from V9 to V7 at the AC fuse terminal block.
- Replace the controller cover and repeat for generator set no. 2.
Underfrequency Adjustment (Over/Underfrequency Relay, Decision-Maker 3+) adjustment
- Turn underfrequency adjustment potentiometer fully clockwise (CW).
- Place master switch in RUN to start the generator set.
- Adjust governor per engine operation manual, engine service manual, or governor section of this manual.
- Slowly turn underfrequency potentiometer counterclockwise (CCW) until LED starts flashing; after about 10 seconds the set shuts down on auxiliary fault.
- Place master switch to OFF/RESET to reset the controller.
- Place master switch to RUN to start the generator set.
- Readjust the governor to the desired frequency as required.
- Place master switch to OFF/RESET to stop the generator set.
2-Wire Low Water Level Sender Test diagnostic
⚠ Hot engine and exhaust system can cause severe injury or death. Do not work on the generator set until it cools.
⚠ Hazardous voltage. Moving parts. Will cause severe injury or death. Operate the generator set only when all guards and electrical enclosures are in place.
Tools: DC voltmeter
- Measure DC voltage between lead 31A (+) and ground (- ) with sender submerged in coolant; voltmeter indicates approximately 12.5 VDC.
- Measure DC voltage between lead 31A (+) and ground (- ) with sender removed from coolant for at least 5-15 seconds; voltmeter indicates a drop to approximately 7 VDC.
3-Wire Low Water Level Sender Test diagnostic
⚠ Hot engine and exhaust system can cause severe injury or death. Do not work on the generator set until it cools.
⚠ Hazardous voltage. Moving parts. Will cause severe injury or death.
Tools: Ohmmeter
- Measure resistance between lead 31 and ground with sender submerged in coolant; ohmmeter indicates a high resistance reading.
- Measure resistance between lead 31 and ground with sender removed from coolant for at least 5-15 seconds; ohmmeter indicates a low resistance reading.
Battery Equalizer Troubleshooting diagnostic
⚠ To prevent reverse polarity damage to the battery equalizer, remove the ground (GND) connection first and attach the ground connection last when disconnecting the battery equalizer.
Tools: 12-volt test light with alligator clips, Voltmeter with 0.01 volt resolution, Battery load tester
- Remove the ground (GND) connections from the battery equalizer; do not allow contact with other connections.
- Verify a differential of 12 volts between the +12 volt and +24 volt terminals using a 12-volt test light; the light will illuminate on a functional unit. Remove the test light.
- Connect the test light between the +12 volt and GND terminals; the light will illuminate on a functional unit.
- With the test light connected, measure and record the voltage between the +12 volt and +24 volt terminals.
- With the test light connected, measure and record the voltage between the +12 volt and GND terminals.
- Remove the test light.
- Compare the values from steps 4 and 5; the difference should be - 0.5 and +0.13 volts on a functional unit.
Oil Pressure Sender Testing diagnostic
Tools: Ohmmeter, Mechanical oil pressure gauge
- Disconnect the oil pressure sender lead 7C.
- Check the sender resistance with an ohmmeter.
- Compare resistance values when the generator set is shut down and when running at operating temperature to Section 1, Specifications.
- Use a mechanical oil pressure gauge to further verify correct readings.
Overcrank Test (Typical) diagnostic
- On gas-fueled sets, disconnect the coil wire at the distributor cap and ground it or disconnect the ignition system.
- On diesel-fueled sets, unplug the fuel injector harness from ECM or disconnect wire no. 70 from the injector pump solenoid.
- Place unit in RUN mode; observe 15-second on-off cranking cycles and maximum 75-second elapsed time to overcrank shutdown.
- Observe controller fault lamp and display for an overcrank shutdown.
- Place unit in OFF/RESET mode.
- Reconnect the ignition coil wire/ignition system, or reconnect the fuel injector harness/wire no. 70.
Speed Sensor Test with Generator Set Running diagnostic
⚠ Keep leads connected to the speed sensor terminals during the test; do not disconnect the leads.
Tools: DC voltmeter
- Connect a DC voltmeter between positive (+) lead (wire 24) at the speed sensor and ground (wire 2) with master switch OFF/RESET; read approximately 8- 12 volts DC.
- Place master switch in RUN to start the generator set.
- Connect DC voltmeter negative probe to 0 terminal (wire 16 white) and positive probe to positive (+) terminal (wire 24 red); read approximately 7- 12 volts DC.
- Place master switch in OFF/RESET to stop the generator set.
- If sensor emits a signal, check continuity of speed sensor leads (wires 2, 16, 24) between controller P1 connector and sensor terminals.
Speed Sensor Test with Separate 12 VDC Source diagnostic
Tools: DC voltmeter, 12-volt battery or DC power supply, Flat piece of iron or steel
- Place master switch in OFF/RESET position.
- Disconnect the speed sensor leads.
- Connect speed sensor, DC voltmeter, and DC voltage source as shown.
- Touch sensing surface with a flat piece of iron or steel at least 4.1 cm (1/4 cu. in.) in size.
- DC voltmeter reading should equal the source voltage, approximately 12 VDC.
- Remove the iron or steel piece and observe a voltmeter reading of 0 VDC.
- If the sensor passes, it is functional; replace if it fails.
- Connect the speed sensor leads and adjust the air gap.
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
| Voltage | Phase | Connection | Leads | Notes |
|---|---|---|---|---|
| 12-lead optional voltage connections | 12 | Alternator optional feature | ||
| 4-lead dedicated voltages | 4 | Alternator standard feature | ||
| 110/127/139/240/254/277 | single-phase | switchable | Towable generator model specifications; some models n/a | |
| 208/220/240/415/440/480 | 3-phase | reconnectable | Towable generator model specifications | |
| 208/220/240/415/440/480 | 3-phase | switchable | Towable generator model specifications |
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 125REOZJG?
The Kohler 125REOZJG is rated 125 kW standby (156.0 kVA).
What engine does the Kohler 125REOZJG use?
The Kohler 125REOZJG is powered by the John Deere 4045HF285K engine.
Is the Kohler 125REOZJG diesel or gas?
The Kohler 125REOZJG runs on Diesel.
What's the oil capacity on a Kohler 125REOZJG?
The John Deere 4045HF285K engine in the Kohler 125REOZJG has an oil capacity of 13.9 liters.
How much coolant does the Kohler 125REOZJG hold?
The Kohler 125REOZJG cooling system holds 19.2 liters (5.1 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.
What is the continuous rating of the Kohler 125REOZJG?
The Kohler 125REOZJG is rated 114 kW prime (143 kVA), against 125 kW standby.
How much does the Kohler 125REOZJG weigh?
The Kohler 125REOZJG has a dry weight of 1226 kg (2702 lb).
What voltage does the Kohler 125REOZJG produce?
The Kohler 125REOZJG is offered in 120/208 V, 127/220 V, 120/240 V, 139/240 V, 220/380 V, 277/480 V, 3-phase.
How many cold cranking amps does the Kohler 125REOZJG require?
The Kohler 125REOZJG uses 1 battery, 12 V each, 800 CCA, per the manufacturer specification sheet.
What alternator comes on the Kohler 125REOZJG?
The Kohler 125REOZJG uses a 4R12X alternator.
What oil filter fits the Kohler 125REOZJG?
The Kohler 125REOZJG uses oil filter part number GM32809.
Which fuel filter part number does the Kohler 125REOZJG take?
The Kohler 125REOZJG uses fuel filter part numbers GM32809, GM50074, GM50006.
What air filter does the Kohler 125REOZJG use?
The Kohler 125REOZJG uses air filter part numbers JOHN DEERE AL204809, JOHN DEERE AT390262.
Troubleshooting
7Fault codes
| Code | Meaning | Remedy |
|---|---|---|
| 32 | High Coolant Temperature | |
| 32A | Emergency Stop | Reset the emergency stop switch. |
| 40 | Pre High Coolant Temp. | |
| 41 | Pre Low Oil Pressure | Check and adjust oil level or replace oil pump. |
| 62 | Low Battery Volts | |
| 63 | Low Fuel | Refuel the generator set. |
| 48 | Emergency Stop |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
7| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 352793 | Oil Filter | 1 | Oil filter | Amazon |
| GM32809 | FILTER, OIL | 1 | Oil filter | Amazon Amazon Amazon Amazon eBay $26.25 NAPA $28.76 |
| GM50006 | Fuel Filter | 1 | Fuel filter | Amazon eBay $26.99 NAPA $44.17 |
| GM50074 | Fuel Filter (primary) | 1 | Fuel filter | Amazon eBay $70.33 NAPA $38.35 |
| GM66704-1 | Fan Belt (12V) | 1 | Belt | Amazon eBay |
| GM66704-2 | Fan Belt (24V) | 1 | Belt | Amazon eBay |
| GM77161 | Oil Filter | 1 | Oil filter | 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.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| Prime | 25% | 10.6 | 2.8 |
| Prime | 50% | 19.5 | 5.1 |
| Prime | 75% | 26.9 | 7.1 |
| Prime | 100% | 34.8 | 9.2 |
| Standby | 25% | 11.4 | 3.0 |
| Standby | 50% | 21.1 | 5.6 |
| Standby | 75% | 29.0 | 7.6 |
| Standby | 100% | 37.4 | 9.9 |
Available documents
Spec sheet (Kohler)Spec sheet — Kohler-125REOZJG (Kohler)Spec sheet — g5361 (Kohler)Spec sheet — tp6356es (Unknown (TP-6356-ES))Reference (Kohler)Reference — 80-125REOZJ Snow Enclosures G6145 (Kohler)Reference — G6-39 0918AZ (Kohler)Reference — Katalog-promyshlennoj-produktsii (Kohler)Service manual — TP-6356 (Kohler)Service manual — decision maker tp6356 (Kohler)Service manual — tp6356 (Kohler)Service manual — tp6798 (Kohler)Service manual — tp7138 (Kohler)Service manual — tp7149 (Kohler)Service manual — tt1649 (Kohler)
This page was generated from the 15 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.