World Leading Portable Generator Parts Supplier How to set Valve Lash Clearances on a Portable Gas Generator The spark plug is located above the valve rocker cover and a bit back under the gas tank. Use a 10mm wrench to remove the valve rocker cover and there they are! Exhaust is on the left. Intake is on the right. Next, remove the spark plug ignition wire. The spark plug is below the heat shield. Use a 13/16th inch spark plug socket to unscrew the spark plug. Insert a screwdriver or similar slender tool into the spark plug hole to indicate the position of the piston. Rotate the crankshaft by CAREFULLY pulling the recoil a small amount at a time. Make sure tool moves freely. The exhaust valve descends first to open. as the piston rises. The exhaust valve closes and immediately the intake valve opens. The piston descends… ..and then the intake valve closes. Even greater gentleness is required to advance the crankshaft so as to stop the piston at top dead center (TDC) With the piston at TDC, the rocker arms will be loose.You can actually wiggle them by hand and feel the slack. To measure the clearance a feeler gauge is required. 14mm and 10mm wrenches are used together to adjust the clearance. Once set to correct clearance, reinstall the spark plug. Reinstall the Valve Rocker Cover. Attached the Ignition wire to the spark plug Insert the PVC tube. Now run your engine to test it is running smoothly. If not, repeat the process. Parts and Valve settings are available on our website.