Cummins/Onan — Preparing Generator Set For Storage
Maintenance
From a Cummins/Onan operator's manual covering: 2.0 EGHAM, 2.5 EGHAA, 3.5 EGHEM, 4.0 EGHAB, 4.0 EGHEB, 5.0 EGHAB, 5.0 EGHEB, 5.0 EGHEM, 6.0 EGHEB. Check it applies to your exact model before use.
Applies to: Cummins/Onan 2.5 EGHAA, Cummins/Onan 4.0 EGHAB, Cummins/Onan 5.0 EGHAB, Cummins/Onan 5.0 EGHEB, Cummins/Onan 6.0 EGHEB, Cummins/Onan Elite E140H engine, Cummins/Onan GH170 engine
Before you start
- Hot oil can cause severe burns.
- Battery electrolyte can cause severe eye damage and burns to the skin.
- Batteries present the hazard of explosion.
Procedure
- Add a fuel preservative and stabilizer such as OnaFresh to the fuel supply; run at 50 percent load for 30 minutes.
- Disconnect the load; turn the fuel supply valve off and remove the air filter.
- As the set runs out of fuel, squirt fogger such as OnaGard into the carburetor intake, then reassemble the air filter.
- When the set stops, remove the spark plug and squirt one tablespoon (about 30 ml) clean engine oil into the spark plug hole; turn the engine over several revolutions; replace the plug.
- Drain the oil base while still warm; refill the crankcase and attach a tag indicating oil viscosity used.
- Electric start models: disconnect battery negative (-) cable first; store battery in a cool dry place and connect to a charger every 30 days.
- Cover the generator set and store in a dry protected area.
Specs & values
- Run at 50 percent load for 30 minutes
- One tablespoon (about 30 ml) clean engine oil
Source: Cummins/Onan operator's 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.