Which step is NOT part of adjusting the valve lash on an OHV engine?

Adjusting the valve lash on an Overhead Valve (OHV) engine is a critical maintenance task that ensures proper engine operation and performance. The process typically involves specific steps to ensure that the clearance between the valve and the rocker arm is set correctly, allowing for optimal engine performance.

Tightening the valve cover is not part of the valve lash adjustment process. This step occurs after the lash has been adjusted and is meant to secure the valve cover in place, preventing oil leaks. It is not involved in the actual measurement or adjustment of the valve lash itself.

In contrast, loosening the set screw and tightening the set screw are direct actions taken in order to adjust the valve lash. Checking clearance is also crucial since it provides the necessary measurements to ensure that the valves are functioning correctly. Engaging in these adjustments allows for the proper operation of the engine's valves, which is essential for overall engine efficiency and longevity.