Cummins/Onan NH-MS/1 / NH-S/1 — Governor Adjustment
Adjustments
For the Cummins/Onan NH-MS/1 / NH-S/1, from the Cummins/Onan service manual.
Browse Cummins/Onan generators & specs →
Procedure
- Adjust the carburetor main jet for best fuel mixture at full load.
- Adjust the carburetor idle needle with no load connected.
- Adjust the length of the governor linkage.
- Check the governor linkage and throttle shaft for binding or excessive looseness.
- Adjust governor spring tension for nominal engine speed at no load.
- Check the rpm drop between no load and full load and adjust governor sensitivity.
- Recheck the speed adjustment.
- Set the carburetor throttle stop screw.
Tools required
- Tachometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Linkage length set so the throttle lever stop is 1/32 inch from the carburetor stop boss
- Nominal no load speed 2400 rpm
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.