Kohler — Gasoline Carburetor Main and Idle Fuel 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 engine, Kohler M20 engine
Before you start
- Do not force the tapered adjusting needles or needle and seat damage will occur.
Procedure
- Stop engine; turn main and idle needles in clockwise until lightly bottomed.
- Back main needle out 2 1/4 turns and idle needle 1 1/2 turns.
- Start engine and run at half load 5-10 minutes to warm.
- Run at 3/4 to full load; turn main needle in until engine runs roughly.
- Turn main needle out 1/4 turn richer than lean limit.
- Set idle fuel needle using same procedure.
Tools required
- screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Main fuel needle preliminary 2 1/4 turns out
- Idle fuel needle preliminary 1 1/2 turns out
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.