KYMCO K-XCT 300i Owner's Manual page 113

2. Periodic Maintenance > Compression Test K- XCT 300i
Engine Compression Test
SAFETY FIRST: Protective gloves and eyewear are recommended at this point.
Remove the seat. See the Seat topic for more information.
Remove the luggage box. See the Luggage Box topic for more information.
Before testing the compression make sure the cylinder head bolts are
tightened securely and the valve clearance is specification. See the
Cylinder Head and Valve Clearance topics for more information.
Remove the spark plug. See the Spark Plug topic for more information.
Thread a compression tester into the spark plug hole hand tight. Hold
the throttle all the way open. Crank the engine with the starter motor
until the needle on the gauge stops rising. Do not crank the engine more
than a few seconds.
2
Cylinder compression 228 ± 28.4 psi
16 ± 2 kg/cm
Low compression is an indication of excessive engine wear, possibly
worn rings or poorly sealing valves, or maybe a tight valve with not
enough valve clearance. High compression is possibly an indication of
excessive carbon buildup on the piston or performance modifications.
Install the spark plug.
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