Generac — Adjust Overspeed Shutdown (Option C Engine Control Circuit Board)
Adjustments · Dual voltage engine control circuit board (Part No. 83089)
From a Generac service manual — check it applies to your exact model before use.
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Before you start
- Steps 2 and 3 MUST be completed BEFORE THE ENGINE IS STARTED; otherwise an overspeed shutdown may occur at normal rated operating speed.
Procedure
- Locate potentiometers R26 (COARSE) and R27 (FINE) and the red LED on the circuit board.
- Turn the COARSE (R26) pot all the way clockwise (CW).
- Turn the FINE (R27) pot all the way counterclockwise (CCW).
- Start the generator engine manually with the Start/Stop switch; let it stabilize and warm up at no-load; adjust governor if needed.
- Slowly turn the COARSE (R26) pot counterclockwise until the red LED just turns on.
- Slowly turn the FINE (R27) pot clockwise until the red LED just goes out.
- Slowly turn the FINE (R27) pot counterclockwise until the red LED just turns on.
Tools required
- screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Overspeed shutdown occurs at approximately 10 Hertz above the unit's normal operating frequency
Source: Generac 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.