Cummins/Onan Onan P4500i / P4500 — Spark Plug Maintenance
Maintenance · Ignition
For the Cummins/Onan Onan P4500i / P4500, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan Onan P4500i, Cummins/Onan P4500
Before you start
- Replace plug if cracked, chipped, or excessively worn.
Parts for this job
Part numbers from the service-parts lists for Cummins/Onan Onan P4500i, Cummins/Onan P4500. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Stop inverter and let cool; move to a flat surface.
- Remove engine service panel to access spark plug.
- Pull the spark plug boot straight off the spark plug.
- Clean area around the spark plug.
- Remove the spark plug with the socket wrench.
- Cover opening with a clean rag to keep dirt out.
- Inspect plug for cracks, wear, and check gap of 0.032 in. (0.80 mm).
- Hand-thread the spark plug back in, then seat with wrench.
- Replace boot and access cover.
Tools required
- Spark plug socket wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Spark plug gap 0.032 in. (0.80 mm)
Full service-parts list: Cummins/Onan Onan P4500i →, Cummins/Onan P4500 →
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.