TE450 SM service manual.pdf - Hyosung

PERIODIC MAINTENANCE 2-24COMPRESSION PRESSUREThe compression pressure reading of a cylinder is agood indicator of its internal condition.The decision to overhaul the cylinder is often basedon the results of a compression test. Periodic maintenancerecords kept at your dealership should includecompression pressure reading for each maintenanceservice.Compression pressureStandard16 kg/cm 2 (at 500 rpm)Service limit 14 kg/cm 2 (at 500 rpm)Low compression pressure can indicate some of thefollowing conditions :● Excessively worn cylinder wall● Worn-down piston or piston rings● Piston rings stuck in grooves● Poor seating of valves● Ruptured or otherwise defective cylinder headgasketNOTEWhen the compression pressure goes belowspecification, check the engine for conditions listedabove.▣ COMPRESSION TEST PROCEDURENOTE Before testing the engine for compressionpressure, make sure that the cylinder headnuts are tightened to the specified torque valuesand valves are properly adjusted. Have the engine warmed up by idling beforetesting. Make sure that the battery is fully-charged condition.Remove the related parts and test the compressionpressure in the following manner.WARNINGThe hot radiator and the hot engine can burn you.Wait until the radiator and the engine are coolenough to touch.● Remove the spark plug.● Fit the compression gauge in the plug holes.Make sure that the connection is tightened.● Keep the throttle lever in full-open position.● Press the starter switch and crank the engine for afew seconds.Record the maximum gauge reading as the compressionof cylinder.Compression gauge : 09915-64511