Cummins/Onan — Out-of-Service Protection

Maintenance · Engine

From a Cummins/Onan service manual — check it applies to your exact model before use.

Applies to: Cummins/Onan NH engine

Procedure

1. Run unit until thoroughly warm.
2. Turn off fuel supply and run until unit stops.
3. Drain oil from oil base while still warm.
4. Refill and attach a warning tag stating oil viscosity used.
5. Remove each spark plug; pour one ounce of rust inhibitor (or SAE #50 oil) into each cylinder.
6. Crank engine slowly by hand several times; install spark plug.
7. Service air cleaner.
8. Clean governor linkage and protect by wrapping with a clean cloth.
9. Plug exhaust outlet to prevent entrance of moisture, dirt, bugs, etc.
10. Wipe entire unit; coat rustable parts with a light film of grease or oil.
11. Provide a suitable cover for the entire unit; disconnect battery and follow standard battery storage.

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.

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