Specifications
| Fuel | Gasoline |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 4 kW |
| Oil capacity | 3.0 L |
| Alternator | Flywheel Alternator |
| Voltage options | 120 V |
| Phase | 1 |
| Rated current | 33 A |
| Circuit breaker | 35 A |
| Battery voltage | 12 V |
| Battery quantity | 1 |
Maintenance & consumables
for the Cummins/Onan 4.0BF| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | ||||
| Fuel filter | — | ||||
| Oil filter | — | ||||
| Battery | — | ||||
| Belt | — | ||||
| Coolant | — | ||||
| Oil | SAE 30 | 3.0 quarts | — | ||
| Spark plug | Gap .020 inch | — |
Common questions
What size generator is the Cummins/Onan 4.0 BF?
The Cummins/Onan 4.0 BF is rated 4 kW standby.
What engine does the Cummins/Onan 4.0 BF use?
The Cummins/Onan 4.0 BF is powered by the Cummins/Onan 4.0BF engine.
What fuel does the Cummins/Onan 4.0 BF use?
The Cummins/Onan 4.0 BF runs on Gasoline.
What's the oil capacity on a Cummins/Onan 4.0 BF?
The Cummins/Onan 4.0BF engine in the Cummins/Onan 4.0 BF has an oil capacity of 3.0 liters.
What alternator comes on the Cummins/Onan 4.0 BF?
The Cummins/Onan 4.0 BF uses a Flywheel Alternator alternator.
Troubleshooting
6Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Bad Battery Connection | BT I | |
| Low Battery | BT I | |
| Wrong Spark | Check ignition system | |
| Out of Fuel Check | Check fuel system | |
| Engine Flooded | Drain excess fuel | |
| Poor Qual ty Fuel | Use high quality fuel |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan 4.0 BF troubleshooting guide (25 entries) →
Repair guides
5- The suggested disassembly procedure is as follows :
- The engine assembly procedure is normally the
- Tappet Adjustment : The engine is equipped with
- Removal:
- Inspection :
Step-by-step procedures compiled from the Cummins/Onan service manual for this model.
Parts
46| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 102-0693 | Gasket, Oil Base Mounting | Gasket | Amazon eBay | |
| 102-0715 | Gasket Kit BF (Power Drawer) | 1 | Gasket | Amazon eBay |
| 102-0743 | Gasket, Oil Drain Plug (Order by Size) 1/2" | 19 | Gasket | Amazon eBay |
| 120-0491 | Pump, Oil | 1 | Pump | Amazon eBay $30.00 |
| 120-0713 | Cup, Intake - Oil Pump | 1 | Pump | Amazon eBay |
| 122-0320 | Adapter, Oil Filter | 1 | Oil filter | Amazon Amazon eBay eBay |
| 306-1975 | Remote start-stop switch (includes indicator light) | Start-stop switch | Amazon eBay | |
| 306-2485 | Deluxe remote control assembly (includes running time meter and battery condition meter) | Remote control | Amazon eBay | |
| 308-0341 | Control Assembly, Remote Starting - Standard (Includes Parts Marked s) | 1 | Switch | Amazon eBay $67.65 |
| 509-0041 | Seal, Bearing Plate | 1 | Seal | Amazon eBay |
| 526-0063 | Gasket (Fuel Tank) | 1 | Gasket | Amazon eBay |
| 102-0711 | Base, Oil Mounting (5/16-18) | Service part / kit | Amazon eBay | |
| 102-0713 | Pan, Oil Oil Pan Mounting | Service part / kit | Amazon eBay | |
| 102-0716 | Plug, Oil Imwn (Order by Size) 1/2" | 1 | Service part / kit | Amazon eBay |
| 104-0779 | Gear, Ring Flywheel (Includes Ring Gear Crankshaft) | 1 | Service part / kit | Amazon eBay |
| 105-0353 | Gear Set, Timing (Includes Camshaft and Crankshaft Gears) | 1 | Service part / kit | Amazon eBay |
| 110-0539 | Spring, Valve | 4 | Service part / kit | Amazon eBay |
| 110-0639 | Lock, Valve Spring | 8 | Service part / kit | Amazon eBay $60.00 |
| 110-0904 | Rotocap, Exhaust | 1 | Service part / kit | Amazon eBay FridayParts $124.86 |
| 110-1924 | Right Side (#2 Cylinder) | Service part / kit | Amazon eBay | |
| 110-1925 | Left Side (#1 Cylinder) Retainer | Service part / kit | Amazon eBay | |
| 110-1935 | *Guide, Valve | 4 | Service part / kit | Amazon eBay |
| 110-1975 | Block Assembly, Cylinder (Excludes Bearing) (Includes parts marked *) | Service part / kit | Amazon eBay | |
| 120-0140 | Spring, Bypass Valve | 1 | Service part / kit | Amazon $2174.00 eBay FridayParts $1096.58 |
| 120-0398 | Plunger, Bypass Valve | 1 | Service part / kit | Amazon eBay |
| 120-0706 | *Tube, Crankcase Oil | Service part / kit | Amazon eBay | |
| 123-1164 | Cap and Indicator, Oil Fill | 1 | Service part / kit | Amazon eBay |
| 123-1174 | Spring, Breather Valve | 1 | Service part / kit | Amazon eBay |
| 123-1175 | Reed, Breather Valve | 1 | Service part / kit | Amazon eBay |
| 123-1208 | Tube, Oil Fill - used up to Serial#W753i2SO14 - BP Only | 1 | Service part / kit | Amazon eBay |
| 123-1225 | Baffle, Breather | Service part / kit | Amazon eBay | |
| 134-2590 | Flywheel (Includes Ring Gear and Magnet Ring) | Service part / kit | Amazon eBay | |
| 150-0078 | Ring, Camshaft Center Pin | 1 | Service part / kit | Amazon eBay |
| 150-0612 | Cup, Governor | 1 | Service part / kit | Amazon eBay |
| 300-2319 | Optional separate neat protection kit for all Aux models. Prevents accidental operation of engine heaters with truck engine running. | 1 | Service part / kit | Amazon eBay |
| 302-0885 | Screw, Machine - Round Head, Black Zinc Finish (#6-32 X 1/2") | 1 | Service part / kit | Amazon eBay |
| 335-0128 | Optional branch load and remote receptacle kit for all Aux models. Includes external weather-proof AC duplex receptacle, wiring and hardware. | 1 | Service part / kit | Amazon eBay |
| 510-0015 | Ball, Fly - Governor | 10 | Service part / kit | Amazon eBay |
| 516-0072 | Pin, Drive - Bearing Stop | 4 | Service part / kit | Amazon eBay |
| 518-0014 | Ring, Retaining | 1 | Service part / kit | Amazon eBay |
| 526-0065 | Baffle, Breather | 2 | Service part / kit | Amazon eBay |
| 526-0066 | C3 | 1 | Service part / kit | Amazon eBay |
| 800-0052 | Screw | 2 | Service part / kit | Amazon eBay |
| 850-0050 | Washer, Lock - Spring (3/8”) | 4 | Service part / kit | Amazon eBay |
| 866-0001 | Nut, Acorn - Valve (Compartment Cover 1/4-20) | Service part / kit | Amazon eBay | |
| 900-0322 | 1 | 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
Parts manual — 965-0262 Onan 4.0KW BFA (spec C-D) Utility Vehicle Genset Parts Manual (01-1988) (Cummins/Onan)Service manual — 900-0322 Onan BFA NH Auxillary Genset Installation manual 11-1981 (Cummins/Onan)Service manual — 965-0315 Onan 4KW BF Power Drawer RV Genset Operator's & Parts manual (06-1973)Service manual — 965-0515 Onan 4KW BF Power Drawer Major Service Manual (09-1973) (Cummins/Onan)Service manual — T-012 Application Of Electric Generating Sets For RVs (8-1979) (Cummins/Onan)