Cummins/Onan — Adjust the governor controller as follows:

For these Cummins/Onan models: MCGBA, MCGCA, MCGDA, MCGDB, MCGGA, MDGDA, MDGDB, MDGDC, MDGDD.

Applies to: Cummins Onan Mcgba, Cummins Onan Mcgca, Cummins Onan Mcgda, Cummins Onan Mcgdb, Cummins Onan Mcgga, Cummins Onan Mdgda, Cummins Onan Mdgdb, Cummins Onan Mdgdc, Cummins Onan Mdgdd

Procedure

1. 1. Push both selector switches (S1, S2) on the controller to their OFF positions.
2. 2. Note that the pots (potentiometers) on the con- troller are adjustable from zero to 100 percent and are marked off in divisions of ten percent.
3. 3. If a remote speed pot is used, set it at its mid- point.
4. 4. Start the set and adjust the Speed pot to obtain the required output frequency: 60 Hertz (1800 RPM) or 50 Hertz (1500 RPM). Warm up the set under load until it is up to normal operating temperature.
5. 5. Disconnect the load and turn the GAIN pot to 100 percent or until operation becomes unsta- ble. Then turn the pot counterclockwise until operation again becomes stable.
6. 6. Adjust D as in Step 5.
7. 7. Adjust I as in Step 5.
8. 8. Readjust Speed if necessary.
9. 9. Manually push the throttle to the minimum speed position and hold it there until the engine reaches minimum speed. Release the throttle and observe speed overshoot. Two to five Hertz overshoot may be acceptable. If over- shoot is unacceptable, turn the I pot clockwise (slightly) to reduce overshoot. If the set hunts during steady state operation, turn the I pot counterclockwise (slightly) until the set is stable.

Source: manual:960-0151B Onan MCGBA CA GA DA DB DA DB DC DD Operators Manual (6-2000) .pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.