The Cummins/Onan G8.3 is an engine rated at 1500 rpm, producing up to 95 kW. It powers generator sets from Cummins/Onan, including the G8.3 Series and G8.3 Series Engine.
Also known as: Cummins G8.3
Part of the Cummins/Onan G8.3 engine family — 2 variants share parts & fitment.
| Rated speed | 1500 rpm |
|---|---|
| Gross power | 95 kW |
How to read your Cummins/Onan engine serial & model number →
Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan G8.3.
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Check | — | 250 hr | ||
| Fuel filter | Check | 05900828 | 250 hr | Amazon eBay | |
| Oil filter | Change | 3375049 | 1500 hr | Amazon eBay | |
| Battery | — | ||||
| Belt | Cooling Fan Belt Tensioner | — | 750 hr | ||
| Coolant | — | ||||
| Coolant filter | Check | — | 1500 hr | ||
| Oil | Change | — | 250 hr | ||
| Spark plug | Check | — | 1500 hr |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Pressure | SAE J1349 test condition: barometric pressure | 29.61 | in. Hg | 100 kPa; 300 ft (91 m) altitude |
| Pressure | SAE J1349 test condition: water pressure | 0.30 | in. Hg | 1 kPa |
| Temperature | Rating note (1): water temperature to aftercooler, or use of air-to-air aftercooler with 100 F or lower air temperature to the radiator | 32 | C (90 F) | applies to 10.5:1 / 10:1 / 11:1 note-(1) ratings |
| Temperature | Rating note (2): water temperature to aftercooler, or use of air-to-air aftercooler with 130 F or lower air temperature to the radiator | 54 | C (130 F) | applies to 8.5:1 note-(2) ratings |
| Temperature | Rating note (3): water temperature to aftercooler, or use of air-to-air aftercooler with 110 F or lower air temperature to the radiator | 32 | C (90 F) | applies to 10.5:1 note-(3) ratings |
| Temperature | Rating note (4): water temperature to aftercooler, or use of air-to-air aftercooler with 130 F or lower air temperature to the radiator | 54 | C (130 F) | applies to 8.5:1 note-(4) ratings |
| Temperature | SAE J1349 test condition: inlet air temperature | 77 | F | 25 C |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Fuel | dry processed natural gas | 905 BTU per standard cubic foot (33.72 kJ/l) lower heating value, used for the tabulated ratings; deration may be required due to altitude, temperature, type of fuel or use of a catalytic converter |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| 3163196 | torque wrench adapter | Adapter |
| 05e00014 | Air Cleaner Element, Paper Type | Air filter |
| 17900012 | Drive Belt, Cooling Fan | Belt |
| 3163099 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3163292 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3164204 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3164486 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3164488 | Digital Multimeter Measure voltage on electrical equipment | Belt |
| 3164491 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3164498 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3376589 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3822524 | Use on v-belts ( 3/8 to 7/8) and v-ribbed belts with 5 ribs or less. | Belt |
| 3822525 | Use on v-beits larger than 7/8 in. and v-ribbed belts with 6 or more ribs. | Belt |
| 3823921 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3823983 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| 3824876 | Belt tension gauge, click type (v-belts‘and v-ribbed with 4 or 5 ribs) | Belt |
| oi900sb | Cooling Fan Belt Tensioner | Belt |
| 08900241 | Coolant Filter | Filter |
| 05200007 | Fuel Filter, NG | Fuel filter |
| 08900244 | Gasket, Low-Temperature Aftercooler (LTA) Water Pump | Gasket |
| 05600009 | Radiator Hoses | Hose |
| Q5e00009 | Radiator Hoses | Hose |
| 08900245 | Rubber Impeller Cap, Low-Temperature Aftercooler (LTA) Water Pump | Impeller |
| 9800wa | Sealing O-Ring, Air/Fuel Mixer | O ring |
| 3375049 | Oil Filter Wrench | Oil filter |
| 0500007 | filter cover | Service part / kit |
| 3376592 | Inch Pound Torque Wrench | Service part / kit |
| 3822735 | Plastic bead blasting media | Service part / kit |
| 3824510 | Cummins electronic cleaner | Service part / kit |
| oj900sb | Crankcase Breather Tube | Service part / kit |
| 08900217 | Low-Temperature Aftercooler (LTA) Water Pump | Pump |
| 08900239 | Low-Temperature Aftercooler (LTA) Water Pump | Pump |
| 13400046 | Spark Plug | Spark plug |
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 G8.3 powers 2 generator set(s), including Cummins/Onan G8.3 Series, Cummins/Onan G8.3 Series Engine.
The Cummins/Onan G8.3 oil change interval is every 250 hours.
A commonly reported issue on generators using the Cummins/Onan G8.3 is: Engine Will Not Reach Rated Speed (RPM). Cause: Load is excessive for engine horsepower rating. Fix: Reduce the load on the engine. Refer to OEM specifications..