Cummins/Onan — Thermo-Magnetic Choke Adjustment
Adjustments
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan NHC-NHCV, Cummins/Onan NHC-NHCV engine
Procedure
- Shut down engine at least one hour; adjust at ambient temperature.
- Loosen screw securing choke body assembly.
- Rotate choke body clockwise to richen or counterclockwise to lean.
- For ambient above 85°F, choke should be fully opened.
- For ambient below 25°F, choke should be opened 1/4 inch with solenoid not engaged.
- Tighten choke body screw.
Specs & values
- Above 85°F: fully open
- Below 25°F: open 1/4 inch with solenoid not engaged
Full service-parts list: Cummins/Onan NHC-NHCV →
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.