Cummins/Onan — Speed Booster Adjustment
Adjustments · vacuum speed booster
From a Cummins/Onan owner's manual covering: 4.0CCK, 4.0CCK-3CR, 5.0 CCK. Check it applies to your exact model before use.
Applies to: Cummins/Onan 4.0CCK, Cummins/Onan 4.0CCK-3CR, Cummins/Onan 5.0 CCK, Cummins/Onan CCK engine
Procedure
- Adjust governor without booster
- Connect booster external spring to bracket on governor link
- At no load, slide bracket to position where external spring has no tension
- Apply full load and check frequency rise
- Lessen internal spring tension if rise is more than 2 hertz
- Increase tension if frequency drops
Specs & values
- Maximum drop of 3 hertz without booster; maximum increase of 2 hertz with booster
Full service-parts list: Cummins/Onan 4.0CCK →, Cummins/Onan 4.0CCK-3CR →, Cummins/Onan 5.0 CCK →
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.