Cummins/Onan — Protection for Extended Out-of-Service Period
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 warning tag to refill before operation.
- Remove each spark plug; pour one ounce (two tablespoons) of rust inhibitor or SAE #50 oil into cylinder; crank engine a few times; reinstall spark plugs.
- Service air cleaner per maintenance schedule.
- Lubricate governor linkage; protect against dust by wrapping with clean cloth.
- Plug exhaust outlet to prevent entrance of bugs, moisture, or dirt.
- Wipe entire unit clean; coat parts likely to rust with light film of grease or oil.
- Provide a suitable cover for entire unit.
- Disconnect battery and follow standard battery storage procedure.
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.