1. Remove the valve cover.
2. Locate the valve tappets. They are located on the top of the cylinder head, and are secured by a locknut and an adjusting screw.
3. Use a feeler gauge to measure the clearance between the valve tappet and the valve stem. The clearance should be 0.008-0.012 inches (0.20-0.30 mm).
4. If the clearance is not within specification, use a flat-blade screwdriver to loosen the locknut on the valve tappet.
5. Use an Allen wrench to turn the adjusting screw until the clearance is within specification.
6. Tighten the locknut to secure the valve tappet in place.
7. Repeat steps 3-6 for the remaining valve tappets.
8. Replace the valve cover.
