The Cummins/Onan 4BTA 3.9-G4 is a 3.92 L 4-cylinder turbocharged engine rated at 1800 rpm. It powers generator sets from Cummins/Onan, including the C80D6 and C90D6. It holds 7.9 L (2.1 gal) of coolant.
Also known as: Cummins 4BTA 3.9-G4
Part of the Cummins/Onan 4BTA3.9 engine family — 6 variants share parts & fitment.
| Coolant capacity | 7.9 L |
|---|---|
| Displacement | 3.92 L |
| Cylinders | 4 |
| Aspiration | Turbocharged |
| Rated speed | 1800 rpm |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | ||||
| Fuel filter | — | ||||
| Oil filter | — | ||||
| Battery | Battery capacity (1x) 75 A/h | — | |||
| Belt | — | ||||
| Coolant | 18.0 l | — | |||
| Oil | 10.9 l | — | |||
| Spark plug | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
The Cummins/Onan 4BTA 3.9-G4 has a displacement of 3.92 liters with 4 cylinders.
The Cummins/Onan 4BTA 3.9-G4 powers 2 generator set(s), including Cummins/Onan C80D6, Cummins/Onan C90D6.