Cummins/Onan 20W-20 — Returning a Unit to Service
Maintenance · Engine
For the Cummins/Onan 20W-20, from the Cummins/Onan service manual.
Applies to: Cummins/Onan 20W-20, Cummins/Onan RDJF engine
Before you start
- Do not smoke while servicing batteries.
Procedure
- Remove cover and protective wrapping; remove plug from exhaust outlet.
- Check warning tag on oil base and verify oil viscosity.
- Clean and check battery; measure specific gravity.
- Check fuel injectors and fuel lines are secure and correctly torqued.
- Clean radiator.
- Connect batteries.
- Verify no loads are connected to engine.
- Start engine.
Specs & values
- Battery specific gravity 1.260 at 77 F
Full service-parts list: Cummins/Onan 20W-20 →
Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.