Cummins/Onan — Governor Adjustment (Includes Anti-dieseling Control)
Adjustments
From a Cummins/Onan owner's manual — check it applies to your exact model before use.
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Before you start
- A lean fuel mixture or a cold engine may cause hunting.
Procedure
- With engine stopped, hold throttle wide open and tension the governor spring.
- Adjust linkage length so the carburetor stop lever clears the stop pin by at least 1/32 inch.
- Move the anti-diesel control set screws away from the carburetor.
- Start the plant and allow it to reach operating temperature.
- Adjust the speed screw for the proper no-load speed from the speed chart.
- Apply a full rated load at 0.8 power factor and recheck speed.
- If hunting, slightly increase distance between governor main shaft and sensitivity screw.
- Tighten all lock nuts when adjustments are complete.
Tools required
- tachometer or frequency meter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
Source: Cummins/Onan owner'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.