Sym Citycom.300i, Service Manual

Page: 29 / 270

2. Maintenance Information
2-8
Cylinder Compression Pressure
Warm up the engine.
Turn off the engine.
Remove the luggage box and the central cover.
Remove the spark plug cap and the spark plug.
Install the compression pressure gauge into the
spark plug hole.
Full open the throttle valve, and start the engine by
the electric starter.
Caution

Run the engine until the reading on the
gauge stops increasing.

Usually, the highest pressure reading will be
obtained in 4~7 seconds.
Compression pressure ： 12‚2 Kg/cmƒ
Check following items if the pressure is too low:

Incorrect valve clearance.
 Valve leaking.
 Cylinder head leaking, piston, piston ring and
cylinder worn out.
If the pressure is too high, it means too much
carbon deposits in the combustion chamber or on
the top of the piston.
CVT system
Drive Belt
Remove the engine left side cover.
Check if the belt is cracked or worn out.
Replace the belt if necessary or in accordance
with the periodical maintenance chart.
Width limit: 22.5 mm or above
Clutch Weight
Run the motorcycle and increase throttle valve
gradually to check the clutch operation.
If the motorcycle vibrates during moving forward,
inspect the wear condition of the clutch weight.
Replace it if necessary.
Teeth
Width
Compression pressure gauge
Clutch weight
To this chapter contents
Clutch spring