Cummins/Onan — Spark Plug Inspection
Maintenance · Ignition system
From a Cummins/Onan operator's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan GGPA, Cummins/Onan GGPB, Cummins/Onan GGPC, General Motors GM 5.0 L engine
Procedure
- Remove the spark plugs and inspect for damaged or cracked insulators, worn electrodes, or excessive carbon deposits.
- Replace the spark plug if any of these conditions are noted.
- Clean those plugs that can be reused and regap to the amount specified in the Specifications section.
- Clean all dirt and grit away from the spark plug seats.
- Lightly lubricate spark plug threads with high temp anti-seize compound.
Specs & values
- Spark plug gap 0.030 inch (0.762 mm)
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.