Kohler M18 / M20 — Check Valve-to-Tappet Clearance
Adjustments · Valves and tappets
For the Kohler M18 / M20, from the Kohler service manual.
Applies to: Kohler M18 / M20 engine
Before you start
- Piston must be at TDC of compression stroke to measure clearance
Procedure
- Remove air cleaner, valve covers, breather, and spark plugs.
- Rotate flywheel and observe tappets; measure clearance on cylinder with no movement.
- Measure with a flat feeler gauge (engine cold).
- Rotate flywheel 360 degrees and measure remaining cylinder.
- If clearance too small, grind valve stems; if too large, replace valves.
Tools required
- Flat feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake .003/.006 in cold
- Exhaust .016/.019 in (serial 1816500646 and earlier)
- Exhaust .011/.014 in (serial 1816500656 and later)
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.