The Cummins/Onan QSB7 is a 6.69 L 6-cylinder turbocharged and charge air cooled engine rated at 1800 rpm, producing up to 125 kW. It powers generator sets from Cummins/Onan, including the C125 D6D, DSGAA and DSGAB. It holds 2 L (0.5 gal) of oil.
Also known as: Cummins QSB7
Part of the Cummins/Onan QSB7 engine family — 7 variants share parts & fitment.
| Oil capacity | 2.0 L |
|---|---|
| Displacement | 6.69 L |
| Cylinders | 6 |
| Aspiration | Turbocharged and charge air cooled |
| Rated speed | 1800 rpm |
| Gross power | 125 kW |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Dry replaceable element | — | |||
| Fuel filter | Single element, 10 micron filtration, spin-on fuel filter with water separator | — | |||
| Oil filter | Spin-on, full flow | — |
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 |
|---|---|---|---|---|
| Other | AC waveform Total Harmonic Distortion (THDV) | < 5% no load to full linear load, < 3% for any single harmonic | % | |
| Other | AC waveform total harmonic distortion | < 5% no load to full linear load, < 3% for any single harmonic | % | |
| Other | Governor regulation class | ISO 8528 Part 1 Class G3 | ||
| Other | Governor regulation class | ISO8528 Part 1 Class G3 | ||
| Other | Random frequency variation | ± 0.50 | % | |
| Other | Telephone Influence Factor (TIF) | < 50 | per NEMA MG1-22.43 | |
| Other | Telephone harmonic factor (THF) | < 3 | ||
| Other | Telephone influence factor (TIF) | < 50 per NEMA MG1-22.43 | ||
| Pressure | Maximum air cleaner restriction with clean filter | 3.7 | kPa | with clean filter |
| Pressure | Maximum back pressure | 10 | kPa | at set rated load |
| Pressure | Maximum cooling air flow static restriction | 0.12 | kPa | |
| Pressure | Maximum fuel inlet restriction with clean filter | 127 | mm Hg | with clean filter |
| Pressure | Maximum return restriction | 152 | mm Hg | |
| Speed | Frequency regulation | Isochronous | ||
| Speed | Overspeed limit | 2100 | rpm | |
| Speed | Random frequency variation | ± 0.25 | % | |
| Speed | Random frequency variation | ± 0.25% | % | |
| Temperature | Standard temperature rise | 150 | °C | Standby at 40 °C ambient |
| Voltage | Random voltage variation | ± 0.5 | % | |
| Voltage | Random voltage variation | ± 0.5% | % | |
| Voltage | Random voltage variation | ± 1.0 | % | |
| Voltage | Voltage regulation, no load to full load | ± 1% | % | |
| Voltage | Voltage regulation, no load to full load | ± 1.0 | % | no load to full load |
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 | Number 2 diesel fuel | Direct injection; single element, 10 micron filtration, spin-on fuel filter with water separator; automatic electric fuel shutoff |
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 |
|---|---|---|
| A047M180 | Filter, Air − Normal Duty | air_filter |
| A054E584 | Filter, Air − Heavy Duty | air_filter |
| A055Z870 | Filter, Air − Replacement − Heavy Duty | air_filter |
| 4915973 | Alternator Manual | alternator |
| 0908-0110-00 | Health and Safety (Diesel Generator Sets) | other_service |
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 QSB7 engine has an oil capacity of 2.0 liters.
The Cummins/Onan QSB7 has a displacement of 6.69 liters with 6 cylinders.
The Cummins/Onan QSB7 powers 3 generator set(s), including Cummins/Onan C125 D6D, Cummins/Onan DSGAA, Cummins/Onan DSGAB.