Cummins/Onan — Spark Plug Replacement/Tightening
Maintenance · Ignition system spark plugs
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan Performer P224 engine
Procedure
- Set the genset control to the Off position.
- Thread the spark plug in by hand until it seats to prevent crossthreading.
- If reusing, turn it with a wrench an additional 1/4 turn. If new, turn an additional 3/8 to 1/2 turn.
- If using a torque wrench, tighten the spark plug to 8 lb-ft (10 N-m).
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Spark plug gap 0.025 inch (0.64 mm)
- Spark plug torque 8 lb-ft (10 N-m)
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.