Cummins/Onan 3.6MKY / 4MKY — Governor Adjustments
Adjustments
For the Cummins/Onan 3.6MKY / 4MKY, from the Cummins/Onan service manual.
Applies to: Cummins/Onan 3.6MKY, Cummins/Onan 4MKY
Before you start
- Disconnect voltage/frequency-sensitive equipment before adjustments.
Procedure
- Run the genset at least 10 minutes at 50% to 75% of rated load; check choke is fully open.
- Check governor linkage for binding or looseness; check motion spring for damage.
- At no-load turn the speed adjustment screw to obtain 62 Hz for a 60 Hz genset (output 123-132 VAC).
- For a 50 Hz genset adjust to 51.5-52.5 Hz (220-231 VAC if rated 220 VAC).
- Check frequency and voltage with load then no load; verify within Table 8-1 limits.
- Adjust governor sensitivity to give closest regulation without hunting; turn CCW to increase.
- Recheck the speed setting and readjust if necessary.
- Set the carburetor throttle stop screw as specified in Fuel System.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 62 Hz no-load (60 Hz)
- 51.5-52.5 Hz no-load (50 Hz)
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.