Kohler — PowerBoost IIIE Voltage Regulator Adjustment
Adjustments
From a Kohler service manual covering: 4CFKM, 4CKM, 5CKM, 5CKM/SCKMR, ACKM/4CKMR. Check it applies to your exact model before use.
Applies to: Kohler 4CFKM, Kohler 4CKM, Kohler 5CKM, Kohler M18 / M20 engine, Kohler M18 engine
Before you start
- High voltage is present at the voltage regulator heat sink.
Procedure
- Turn voltage, volts/Hz and stability pots fully counterclockwise.
- Start generator set; rotate voltage pot to desired output voltage.
- Rotate stability pot clockwise until light flicker is minimized.
- Readjust voltage adjustment pot if necessary.
- Set engine speed to cut-in frequency (56.3 Hz or 46.3 Hz).
- Turn volts/Hz pot clockwise until voltmeter reading just begins to drop.
- Readjust engine speed to normal (1800 or 1500 rpm).
- Readjust voltage and stability pots as necessary.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Voltage range approx. 100-130 FridayParts $30.67 volts
- Cut-in 56.3 Hz (60 Hz models) or 46.3 Hz (50 Hz models)
Full service-parts list: Kohler 4CFKM →, Kohler 4CKM →, Kohler 5CKM →
Source: Kohler 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.