2004 Poalaris MSX110, MSX150 PWC Original Service Manual, Page 31Get this manual
MAINTENANCE Engine Compression Test
A cylinder compression test is one of the most accurate methods in determining the condition of internal engine componentsAlways perform the compression test with fully charged batteryEngine should rotate at least 300 RPM1Remove both ignition coil packs from the valve coverRemove both spark plugs2Remove both fuel injector harness connectors3Install the compression gauge into one of the cylinders4Insert the lanyard and push the starter button for no more than 15 secondsObtain reading from gauge, then release gauge pressure5Measure remaining cylinder6Reassemble in reverse orderTighten fasteners to specification