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Home›Repair guides›Cummins/Onan›Mechanical Governor Adjustments

Cummins/Onan — Mechanical Governor Adjustments

Adjustments

From a Cummins/Onan service manual — check it applies to your exact model before use.

Applies to: Cummins/Onan MDGDA, Cummins/Onan MDGDB

Before you start

  • Do not adjust the idle speed screw or break its wire seal. Doing so can void the generator set warranty.

Procedure

  1. Run engine at normal operating temperature under full load.
  2. Turn the governor speed adjusting screw to adjust output frequency (50 Hz or 60 Hz).
  3. Adjust droop to within five percent of nominal frequency.
  4. Check operation under various loads; increase droop if the governor hunts.
  5. Readjust full-load frequency if droop is adjusted.
  6. Do not adjust the idle adjusting screw; it is factory set and sealed.

Specs & values

  • Droop within 5 percent of nominal frequency (3 Hertz for 60 Hertz sets, 2.5 Hertz for 50 Hertz sets)

Full service-parts list: Cummins/Onan MDGDA →, Cummins/Onan MDGDB →

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.

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