Cummins/Onan 12.0 RDJC — Governor Speed Adjustment
Adjustments
For the Cummins/Onan 12.0 RDJC, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan RDJC
Before you start
- Excessive droop may be caused by engine misfiring; correct before adjusting governor.
Procedure
- Turn governor spring nut clockwise (more spring tension) to increase rpm.
- Turn counterclockwise to reduce governed speed.
- Hold a tachometer against the flywheel-crankshaft cap screw or observe a frequency meter.
Tools required
- tachometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 1800 rpm = 60 hertz
- 1500 rpm = 50 hertz
Full service-parts list: Cummins/Onan RDJC →
Source: Cummins/Onan operator'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.