2-32 PERIODIC MAINTENANCE COMPRESSION PRESSURE CHECK The compression pressure reading of a cylinder is a good indicator of its internal condition. The decision to overhaul the cylinder is often based on the results of a compression test. Periodic mainte- nance records kept at your dealership should include compression readings for each maintenance service. COMPRESSION PRESSURE SPECIFICATION Standard Limit Difference 1 300 – 1 700 kPa 1 000 kPa 200 kPa 2 2 2 (13 – 17 kgf/cm , 185 – 242 psi) (10 kgf/cm , 148 psi) (2 kgf/cm , 28 psi) Low compression pressure can indicate any of the following conditions: * Excessively worn cylinder walls * Worn piston or piston rings * Piston rings stuck in grooves * Poor valve seating * Ruptured or otherwise defective cylinder head gasket Overhaul the engine in the following cases: * Compression pressure in one of the cylinders is 1 000 kPa (10 kgf/cm2, 148 psi) and less. 2 * The difference in compression pressure between any two cylinders is 200 kPa (2 kgf/cm , 28 psi) and more. * All compression pressure readings are below 1 300 kPa (13 kgf/cm2, 185 psi) even when they measure 2 E 1000 kPa (10 kgf/cm , 148 psi) and more. L COMPRESSION TEST PROCEDURE P NOTE: M * Before testing the engine for compression pressure, make sure that the cylinder head nuts are tightened to the specified A torque values and the valves are properly adjusted. S * Have the engine warmed up before testing. * Make sure that the battery is fully-charged. Remove the related parts and test the compression pressure in the following manner. • Lift and support the fuel tank. (5-3) • Remove all the spark plugs. (2-5) • Install the compression gauge and adaptor in the spark plug hole. Make sure that the connection is tight. • Keep the throttle grip in the fully opened position. • Press the starter button and crank the engine for a few sec- onds. Record the maximum gauge reading as the cylinder compression. • Repeat this procedure with the other cylinders. 09915-64512: Compression gauge set 09913-10750: Adaptor