3. LUBRICATION SYSTEM VITALITY 50 CYLINDER COMPRESSION Warm up the engine before compression test. Remove spark plug cover. ( 13-5) Remove the spark plug and insert a compression gauge. Open the throttle valve fully and push the starter button for 78 seconds to test the compression. Compression: 2-Stroke: 11.8kg/cm 4-Stroke: 14kg/cm If the compression is low, check for the following: · Leaking cylinder head gasket · Worn piston/cylinder If the compression is high, it indicates that carbon deposits have accumulated on the combustion chamber and the piston head. 3-13