Cummins/Onan — Returning Unit to Service
Maintenance · Engine
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan NHC-NHCV engine
Before you start
- Exhaust gas is deadly! Exhaust gases contain carbon monoxide, a poisonous gas that can cause unconsciousness and death.
Procedure
- Remove cover and protective wrapping; remove plug from exhaust outlet.
- Check tag on oil base and verify oil viscosity for ambient temperatures.
- Clean and check battery; measure specific gravity (1.260 at 77°F [25°C]) and verify level to split ring.
- Charge or add distilled water if specific gravity or level is low.
- Check fuel filter and fuel lines are secure with no leaks.
- Check carburetor and adjust if necessary.
- Connect battery.
- Start engine in well ventilated area. Exhaust smoke at start is normal.
Tools required
- hydrometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Battery specific gravity: 1.260 at 77°F (25°C)
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.