Cummins/Onan — Spark Plug Maintenance
Maintenance
From a Cummins/Onan owner's manual covering: Onan P4500iDF, P4500iDF, P4500iDF Inverter. Check it applies to your exact model before use.
Applies to: Cummins/Onan P4500iDF, Cummins/Onan P4500iDF Inverter
Before you start
- Never apply any side load or move the spark plug laterally when removing it.
Parts for this job
- A058V025 Spark plug — Cummins/Onan P4500iDF Amazon eBay
- A058V025 Spark plug — Cummins/Onan P4500iDF Inverter Amazon eBay
Part numbers from the service-parts lists for Cummins/Onan P4500iDF, Cummins/Onan P4500iDF Inverter. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Place the generator on a level surface and allow the engine to cool.
- Remove the engine service cover.
- Remove the spark plug boot by firmly pulling it directly away from the engine.
- Clean the area around the spark plug.
- Remove the spark plug with the included spark plug socket wrench.
- Inspect the spark plug; replace if electrodes are pitted, burned, or insulator is cracked.
- Measure the electrode gap with a wire-type feeler gauge; correct by bending the side electrode.
- Install the spark plug finger tight, then tighten an additional 3/8 to 1/2 turn.
- Install the spark plug boot and engine service cover.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
Full service-parts list: Cummins/Onan P4500iDF →, Cummins/Onan P4500iDF Inverter →
Source: Cummins/Onan owner'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.