The Cummins/Onan 4BT3.9-G4 is a 3.92 L 4-cylinder turbocharged engine rated at 1500 rpm, producing up to 73.9 kW. It powers generator sets from Cummins/Onan, including the 50 DGCA, C50 D6, C60 and C65D6. It holds 10.9 L (2.9 gal) of oil and 21.2 L (5.6 gal) of coolant.
Also known as: Cummins 4BT3.9-G4
Part of the Cummins/Onan 4BT3.9 engine family — 9 variants share parts & fitment.
| Oil capacity | 10.9 L |
|---|---|
| Coolant capacity | 21.2 L |
| Displacement | 3.92 L |
| Cylinders | 4 |
| Aspiration | Turbocharged |
| Rated speed | 1500 rpm |
| Gross power | 73 kW |
This engine also powers 16 machine(s) on Power Equipment Info.
| Part # | Description | Category |
|---|---|---|
| 140-0710 | Air Cleaner, Standard | air_filter |
| 309-0272 | Air Cleaner - Heavy Duty (10" Inlet Tube) | air_filter |
| 505-0104 | air_filter | |
| 982-0200 | Air Filter | air_filter |
| AN500T0083 | ALTERNATOR | alternator |
| 150-2007 | Guard. Belt Screw. Cap - Hex Head (1/2-13 X 2-1/4“) | belt |
| 187-0008 | Belt, Drive | belt |
| 353-0094-01 | Connector Housing and Contact Pins, 8 Pin (Less Pins) | connector |
| 3824469 | fuel pump gear puller | fuel_pump |
| 102-1147 | Gasket, Drain - Oil Pan | gasket |
| 187-0002 | Gasket Kit, End - Top | gasket |
| 187-0012 | Gasket, Cover - Valve | gasket |
| 526-0018 | Gasket, Flange (1-3/4) | gasket |
| DM-3801371 | Gasket Set - 4BT 3.9 | gasket |
| FP-4B39PREM | 4B/4BT3.9 In-Frame Kit w/upper gasket set & oil pan gasket | gasket |
| FP-4B39PREML | 4B/4BT3.9 In-Frame Kit w/upper gasket set & oil pan gasket (late) | gasket |
| FP-IFK4B39PREM | 4B/4BT3.9 In-Frame Kit w/upper gasket set & oil pan gasket | gasket |
| FP-IFK4B39PREML | 4B/4BT3.9 In-Frame Kit w/upper gasket set & oil pan gasket (late) | gasket |
| 503-0365 | Heater, Engine - 750 Watt (120 volt) | heater |
| 332-0051 | Clip, Wire - Fuel Hose---— | hose |
| 503-0098 | Hose, Oil Drain - Bulk (3/4 | hose |
| 503-0183 | Clamp, Hose | hose |
| 503-0685 | Clamp, Hose | hose |
| DM-3805455 | Oil Cooler Hose - 4BT 3.9 | hose |
| 3822509 | injector puller | injector |
| 3823276 | injector bore brush | injector |
| DM-3029550 | Fuel Injector - 4BT 3.9 | injector |
| 140-2164 | Nut, Square (1/4-20) | nut |
| 140-0705 | Oil Filter | oil_filter |
| 102-1237 | Adapter, Oil Drain (Ml8 x 1/2") (S2) | other_service |
| 145-0596 | other_service | |
| 150-2187 | Lever, Actuator - Governor | other_service |
| 150-2203 | other_service | |
| 150-2218 | other_service | |
| 150-2251 | Joint, Ball | other_service |
| 151-0611 | Control, Governor | other_service |
| 151-0632 | other_service | |
| 154-2581 | other_service | |
| 155-2062 | other_service | |
| 155-2080 | other_service | |
| 155-2175 | Clamp, Muffler 4" | other_service |
| 155-2256 | other_service | |
| 155-2353 | other_service | |
| 187-0004 | other_service | |
| 187-0007 | other_service | |
| 187-0011 | Filter, Fuel | other_service |
| 187-0015 | Filter, Oil | other_service |
| 187-0017 | other_service | |
| 187-0018 | other_service | |
| 187-0146 | other_service | |
| 187-0198 | other_service | |
| 309-0553 | other_service | |
| 309-0554 | other_service | |
| 323-1304 | tiotming, Umector | other_service |
| 332-0325 | other_service | |
| 332-0941 | other_service | |
| 332-1087 | other_service | |
| 332-1279 | Insulated | other_service |
| 332-1445 | Tie, Cable 18 98-5219 1 Decal - Panel Front (Not I l l u s t r a t e d ) 19 98-5220 1 Decal | other_service |
| 332-2739 | Bracket | other_service |
| 333-0291 | other_service | |
| 333-0292 | other_service | |
| 3377259 | bosch timing tool (ve) | other_service |
| 353-0094 | other_service | |
| 357-0030 | RECTIFIER ‘BATT CHARGING | other_service |
| 416-0446 | Cable, Battery (#2/0) 12-1/2" (Jumper) | other_service |
| 416-0893 | other_service | |
| 416-0921 | other_service | |
| 501-0441 | Line, Fuel - Flex (Fuel In) | other_service |
| 501-0502 | Line, Fuel - Flex (Fuel out) | other_service |
| 503-0197 | other_service | |
| 504-0011 | Valve, Shutoff (1/2”) | other_service |
| 505-0026 | Coupling, Pipe (1/8") | other_service |
| 505-0050 | Nut, Cap - Hex Head (#10-32 x 30mm) | other_service |
| 505-0059 | other_service | |
| 505-0098 | Band | other_service |
| 505-0185 | other_service | |
| 505-1373 | other_service | |
| 526-0008 | other_service | |
| 526-0115 | Washer (5/16 “) | other_service |
| 526-0196 | Washer, Spacer - Shield JC)INT, BALL LINKAGE | other_service |
| 526-0327 | other_service | |
| 800-0012 | Screw, Cap - Hex Head (1/4-20 x 2-1/4”) Begin Spec C MANIFOLD KIT, INTAKE | other_service |
| 800-1003 | other_service | |
| 800-2060 | 016-40820 NE 1 Screw. Cap - Hex Head (M8-1.25 x 35MM) 3 856-0008 | other_service |
| 800-2110 | Hood, Inlet - Air Molded | other_service |
| 800-2112 | Screw. Cap - Hex Head (M12 x 30nin) | other_service |
| 812-0075 | other_service | |
| 813-0103 | other_service | |
| 815-0172 | Cover, Adapter Outlet | other_service |
| 850-0025 | other_service | |
| 850-0030 | Washer, Lock - Spring (#10) | other_service |
| 850-0050 | Washer, Lock - Spring (3/8”) | other_service |
| 850-2006 | Washer, Lock - Spring (M6) | other_service |
| 850-2008 | Heater, Engine Coolant | other_service |
| 850-2012 | Washer, Lock - Spring (M12) | other_service |
| 856-0013 | other_service | |
| 860-2007 | Screw, Machine - Round Head (M10 x 32 x 3/4") | other_service |
| 870-0053 | other_service | |
| 870-0131 | other_service | |
| 870-0212 | Nut, Locking (1/4-20) | other_service |
| 871-0010 | ENut, Hex (10-32) ‘853-0006 Elackwasher 526-004$ | other_service |
| 871-0028 | other_service | |
| 928-0502B | other_service | |
| 928-0506 | other_service | |
| 960-0135 | other_service | |
| 960-0136 | Battery, 24V, 55Ah, AGM | other_service |
| 960-0242 | other_service | |
| 960-0504A | other_service | |
| 960-0505 | other_service | |
| 960-12 | other_service | |
| 965-0520 | Cooling Fan | other_service |
| DM-3802010 | Main Bearing Set Standard - 4BT 3.9, 6BT 5.9, 6CT 8.3 | other_service |
| K19-CP | 460 kWe | other_service |
| K38-CP | 920 kWe | other_service |
| K50-CP | 1240 kWe | other_service |
| 110-0426 | Water Pump | pump |
| 187-0001 | Pump, Water | pump |
| 187-0013 | Pump, Transfer - Fuel | pump |
| 187-0020 | Pump, Injection | pump |
| DM-3004242 | Fuel Transfer Pump - 4BT 3.9 | pump |
| DM-3805403 | Water Pump - 4BT 3.9, 6BT 5.9 | pump |
| DM-3807788 | Oil Pump - 4BT 3.9 | pump |
| 323-1200 | Resistor, Fixed, Wirewound AR | resistor |
| 323-1306 | Screw, Cap - Hex Head (1/4-20 x 1/2") | screw |
| 750-1010 | Screw, Machine - Fillister Head (1/4-20 x 1") | screw |
| 800-0048 | Screw, Cap - Hex Head (3/8 - 16 X 3/4") | screw |
| 110-0430 | Seal, Water Pump | seal |
| 150-2201 | Sensor, Speed – Magnetic | sensor |
| 193-0244 | Sender, Oil Pressure (E1) | sensor |
| 193-0353 | Sender, Temperature - Oil | sensor |
| 193-0375 | # Sender, Water Temperature | sensor |
| 405-3826-01 | Support, Engine - Screw, Cap - Hex Head (M12 x 1.75 x 65mm) | support |
| 309-0269 | Air Cleaner (Includes Element) - Standard | switch |
| 309-0561 | Switch, Temperature - Washer, Lock (#10) | switch |
| 332-2921 | Switch, Temperature - Washer, Lock (M8) | switch |
| 187-0009 | Thermostat | thermostat |
| 187-0010 | Gasket, Thermostat | thermostat |
| 821-0018 | Thermostat (Includes Plugs) | thermostat |
| DM-3015282 | Thermostat 180F - 4BT 3.9, 6BT 5.9 | thermostat |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
The Cummins/Onan 4BT3.9-G4 engine has an oil capacity of 10.9 liters.
The Cummins/Onan 4BT3.9-G4 has a displacement of 3.92 liters with 4 cylinders.
The Cummins/Onan 4BT3.9-G4 powers 8 generator set(s), including Cummins/Onan 50 DGCA, Cummins/Onan C50 D6, Cummins/Onan C60, Cummins/Onan C65D6, Cummins/Onan C70-D5.