Valve adjustment caps are small caps placed on the valve stems to adjust the valve clearance. They are used to adjust the valve height and thus ensure the correct opening and closing of the valves.
The valve adjustment caps are available in various sizes and are usually made of high-strength steel or plastic. They are manufactured with precise dimensional tolerances to adjust the valve clearance according to the manufacturer's specifications.
When maintaining the engine, it is important to regularly check the valve lash and adjust it if necessary. This is done by removing the valve adjustment caps and replacing them with others of the correct thickness to achieve the desired valve clearance. Correct valve adjustment is crucial for good engine performance, clean combustion and minimal valve chatter.