Cummins/Onan — Variable Speed Governor Adjustment
Adjustments
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Make sure carburetor is adjusted correctly.
- Adjust throttle stop screw on carburetor to minimum idling speed of 1450 rpm so governor spring can hold engine at 1500 rpm.
- Adjust governor spring tension for minimum speed: shift lever to minimum position, no load, adjust for about 1500 rpm.
- Adjust sensitivity at minimum speed: move governor spring outward to decrease sensitivity, inward to increase.
- Apply full load and shift speed control lever until engine reaches desired maximum speed.
- Set screw in bracket slot to stop lever travel at desired maximum full-load speed position.
Tools required
- tachometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Full-load speed 3600 rpm recommended maximum for continuous operation.
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.