Cummins/Onan — Valve Clearance Adjustment (RDJEA)
Adjustments · valve train
From a Cummins/Onan service manual — check it applies to your exact model before use.
Browse Cummins/Onan generators & specs →
Procedure
- Rotate flywheel clockwise until cylinder number 1 is up on compression stroke and the TC mark aligns with the timing pointer.
- Turn 10 to 45° past TC to be sure the lifter moves off the cam ramp.
- Adjust both intake and exhaust valves to 0.017 inch (0.43 mm).
- Check clearance between rocker arm and valve with a feeler gauge; adjust with the lock nut.
- For number 2 cylinder, turn flywheel clockwise 180 degrees from the Step 1 position (between 10 and 45 degrees past bottom center).
- Adjust number 2 cylinder valve clearance as in Step 4.
Tools required
- Feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve clearance 0.017 inch (0.43 mm), cold
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.