Align the first piston at the top of its travel when pressing the air into the engine. Lift off the engine cover by pulling, before taking out the ball stud. Unconnect the battery cable from where it connects to its ground terminal. Clean around the spark plug openings with compressed air, if available. Then pull out the spark plugs to keep any dirt and debris from falling into the engine. Remove the valve cover. Take measurements for the valve set by finding two lobes facing straight up on one cylinder while spinning the
Camshaft. We will take these measurements now to help us pick the right replacement lifters later. Keep checking camshaft lobes as you spin the camshaft. Take out the camshaft(s) for the valves you plan to tweak. Take a micrometer to measure each lifter's height and replace each one in its cylinder head until all lifters have been measured. Keep track of each lifter's measurement. To find the right replacement lifter that gets the valve gap where it should be, work out the difference by using the equation S - C = change. In this equation, S is the needed valve clearance number, and C is the measurement of the current gap. Pull out the lifter and note the size value from underneath it. Then reduce the lifter length by finding the needed valve clearance difference from your measurement reading or getting it as close as possible to your calculation results. Install the camshaft(s). Make sure you recheck the valve clearances and see if they stay in the accepted range. Later stages of installation work in the opposite direction as removal did.