Cummins/Onan B43 / B48 — Carburetor and Governor Adjustment

Adjustments · Governor / carburetor

For the Cummins/Onan B43 / B48, from the Cummins/Onan operator's manual.

Applies to: Cummins/Onan B48

Procedure

1. Start engine and allow it to warm up thoroughly (at least 10 minutes).
2. Move engine speed control to the slow position.
3. Bend or turn the low speed stop on the governor so the throttle stop screw on the carburetor controls engine speed.
4. Adjust the throttle stop screw for 1000 rpm idle.
5. Adjust the governor low speed stop for 1100 rpm idle.
6. Move engine speed control to the fast position.
7. Bend the high speed stop on the governor so the engine runs at the vehicle manufacturer's recommended speed.

Full service-parts list: Cummins/Onan B48 →

Source: Cummins/Onan operator'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.

More Cummins/Onan repair guides →