: Always measure the clearance again after tightening the lock nut to ensure accuracy. Tappet Guides

"Tapeet mootor" is an Estonian phrase referring to (mootori tõukurid) in an engine. Tappets (or valve lifters) are critical components that convert the rotational motion of the camshaft into linear motion to open and close intake and exhaust valves. Engine Tappet Adjustment Guide

A is the sleeve or housing that keeps the tappet moving in a perfectly straight line. DOC HARLEY: TAPPET GUIDE ALIGNMENT TOOL USES

: Remove the valve (rocker) cover. Always check your specific engine's service manual for the correct clearance specifications.

: Insert a feeler gauge between the tappet and the valve stem (or rocker arm). The gauge should have a "slight drag" when pulled through. Adjust : Loosen the lock nut using a spanner.

: Hold the adjuster screw stationary while tightening the lock nut to prevent the setting from changing.

: Rotate the engine manually to Top Dead Center (TDC) for the cylinder you are adjusting. This ensures the valves are fully closed and the tappet is on the base circle of the cam lobe.