Cummins/Onan — Protection for Extended Out-of-Service Period (>30 days)
Maintenance · Engine
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Discharged batteries are subject to severe damage if exposed to freezing temperatures.
Procedure
- Run engine until thoroughly warmed up.
- Turn off fuel supply and run until engine stops from lack of fuel.
- Drain oil from oil base while still warm; attach a warning tag to refill before operation.
- Remove each spark plug and pour one ounce of rust inhibitor (or SAE #50 oil) into each cylinder; crank a few times and reinstall plugs.
- Service the air cleaner per maintenance schedule.
- Lubricate governor linkage and wrap against dust.
- Plug exhaust outlet and provide a suitable cover for the entire unit.
- Disconnect battery and follow standard battery storage procedure.
Specs & values
- 1 ounce (two tablespoons) rust inhibitor per cylinder
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.