Remove the plug, and the valve cover. Turn the engine over by hand while watching the piston. Set the piston 1/4 inch past TDC with both valves closed. Set the intake valve at .003-005 and the exhaust at .005-.007. The intake valve should be the bottom valve on the head when looking from above. reassembly and see what happens, If that doesn't fix it post back for further instructions for checking the compression release.