Cylinder Compression Test - KYMCO 2006 MXU 500 Off-Road Owner's Manual

8. CYLINDER HEAD/VALVES

CYLINDER COMPRESSION TEST

Warm up the engine to normal operating
temperature.
Stop the engine and remove the spark plug
cap and remove the spark plug (refer to the
"SPARK PLUG" section in the chapter 3).
Install a compression gauge into the spark
plug hole.
Open the throttle all the way and crank the
engine with the starter motor until the gauge
reading stops rising.
The maximum reading is usually reached 4 –
7 seconds.
＊
To avoid discharging the battery, do not
operate the starter motor for more than
seven seconds.
Compression pressure:
15 kg/cm
Low compression can be caused by:
Blown cylinder head gasket
Improper valve adjustment
Valve leakage
Worn piston ring or cylinder
High compression can be caused by:
Carbon deposits in combustion chamber or
on piston head
2
(1500 kPa, 213 psi)
Park Plug Cap
Compression Gauge
MXU 500
8-4