The Cummins/Onan QSK50 - G24 / G25 is a 49.8 L 16-cylinder turbocharged and charge air cooled engine rated at 1800 rpm, producing up to 2204 kW. It powers generator sets from Cummins/Onan, including the C1750D6E and C2000D6E. It holds 121 L (32.0 gal) of oil and 140 L (37.0 gal) of coolant.
Also known as: Cummins Inc. QSK50 - G24 / G25
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Dry replaceable element | | — | | |
| Fuel filter | Two-stage, spin-on fuel filter and water separator system. Stage 1: remote mounted, 5 µm duplex filter with two priming pumps. Stage 2: engine mounted, 3 µm triple element filter | | — | | |
| Oil filter | Four spin-on, combination full flow filter and bypass filters | | — | | |
| Coolant | 140 L (37 US gal) | 140.0 L | — | | |
| Oil | 121 L (32.0 US gal) | 121.0 L | — | | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Parts cataloged across the Cummins/Onan QSK50 family
20| Part # | Description | Category |
|---|
| 140-3230 | Cleaner, Air (Includes Elements - See Ref. No. 25 and 26) | Air filter |
| 140-3963 | Cleaner, Air (Spec A-C Metal) | Air filter |
| 70781N | Element, Primary - Air Cleaner - Nelson - Heavy Duty | Air filter |
| 70782N | Element, Safety - Air Cleaner - Nelson - Heavy Duty | Air filter |
| AF25544 | Element, Primary - Air Cleaner - Fleetguard - Heavy Duty | Air filter |
| AF25545 | Element, Safety - Air Cleaner - Fleetguard - Heavy Duty | Air filter |
| AF2559300 | Air Cleaner replacement element (Nelson), for Air Cleaner Housing 140-3737 | Air filter |
| 149-2792 | Filter, Fuel | Fuel filter |
| 149-2837 | Filter, Fuel | Fuel filter |
| 149-2853 | Filter, Fuel (Triplex Filter) | Fuel filter |
| 543-0088 | Package, Fuel Filter | Fuel filter |
| A030M222 | Filter, Fuel (Triple Filter) | Fuel filter |
| 501-0970-01 | Line, Fuel | Hose |
| 503-1705 | Hose, Hump | Hose |
| 503-2754-01 | Hose, Oil | Hose |
| 503-2754-02 | Hose, Oil | Hose |
| 102-1335 | Plug, Oil Drain | Service part / kit |
| 140-1260 | Fitting, Safety Filter | Service part / kit |
| 140-1548 | Indicator, Service | Service part / kit |
| 6794600 | Washer, Sealing | Seal |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Common questions
What is the oil capacity of the Cummins/Onan QSK50 - G24 / G25?
The Cummins/Onan QSK50 - G24 / G25 engine has an oil capacity of 121.0 liters.
What is the displacement of the Cummins/Onan QSK50 - G24 / G25?
The Cummins/Onan QSK50 - G24 / G25 has a displacement of 49.8 liters with 16 cylinders.
Which generators use the Cummins/Onan QSK50 - G24 / G25 engine?
The Cummins/Onan QSK50 - G24 / G25 powers 2 generator set(s), including Cummins/Onan C1750D6E, Cummins/Onan C2000D6E.