Cummins/Onan GS-107-AC — Adjusting valve clearance
Adjustments · Cylinder head
For the Cummins/Onan GS-107-AC, from the Cummins/Onan service manual.
Applies to: Hol-Gar GS-107-AC, Cummins/Onan J120-S/967F engine
Procedure
- Check clearance with engine at room temperature (about 70 F).
- Turn flywheel so cylinder is 10 degrees past TDC of compression stroke.
- Adjust clearance with the self-locking nut.
- Set intake clearance to 0.012 inch and exhaust to 0.015 inch.
Tools required
- Feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake 0.012 in
- Exhaust 0.015 in
Full service-parts list: Hol-Gar GS-107-AC →
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.