Cummins/Onan 3.6MKY / 4MKY — Governor Adjustment
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
- Voltage/frequency-sensitive equipment may be damaged by power line frequency variations
Procedure
- Run genset at least 10 minutes at 3/4-rated load; check choke completely open.
- Check governor linkage for binding or excessive looseness; check motion spring.
- At no-load, turn speed adjustment screw to obtain 62-63 Hz (60 Hz) or 51.5-52.5 Hz (50 Hz).
- Check frequency and voltage with load and no load against Table 8-1 limits.
- Adjust governor sensitivity for closest regulation without hunting.
- Recheck speed setting and readjust if necessary.
- Set carburetor throttle stop screw as specified in FUEL SYSTEM.
Tools required
- Digital frequency/voltmeter (0.3% freq accuracy, 0.5% voltage accuracy) Amazon
- Digital ammeter Amazon
- Variable load bank with 4 kW capacity Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
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.