Cummins/Onan — Electric Governor Preliminary Adjustment
Adjustments · Cummins model EFC electric governor
From a Cummins/Onan owner's manual covering: 230NT2, 230NT4, 250NT3, 275NT6, 275NTA1, 300NTA2, 350NTTA2, NT-855, NTA-855, NTTA-855-G2. Check it applies to your exact model before use.
Applies to: Cummins/Onan 350NTTA2, Cummins/Onan NT-855-G2 engine, Cummins/Onan NT-855-G4 engine, Cummins/Onan NT-855-G3 engine, Cummins/Onan NT-855-G6 engine, Cummins/Onan NTA-855-G1 engine, Cummins/Onan NTA-855-G2 engine, Cummins/Onan NTTA-855-G2 engine
Procedure
- Idle Speed potentiometer: turn counterclockwise 20 turns, then clockwise 10 turns (mid position).
- Run Speed potentiometer: turn counterclockwise 20 turns, then clockwise 10 turns (mid position).
- Gain potentiometer: turn screw fully counterclockwise.
- Droop potentiometer: fully counterclockwise for isochronous, approx. 40 for 3 percent droop, approx. 80 for 5 percent droop.
Tools required
- Frequency meter or tachometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Droop adjustable zero percent (isochronous) to 5 percent
Full service-parts list: Cummins/Onan 350NTTA2 →
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.