Cylinder Compression Pressure; Driving System - Sym ATTILA RS-21 EFi 150 Service Manual

Cylinder Compression Pressure

Warn up engine and then turn off the engine.
Remove the trunk and the central cover.
Remove spark plug cap and spark plug.
Install compression gauge.
Full open the throttle valve, and rotate the engine
by means of stepping the foot-starting lever.
Caution
Rotate the engine until the reading in the
gauge no more increasing.
Usually, the highest pressure reading will be
obtained in 4~7 seconds.
Compression pressure: 12 ± 2 Kg/cm²
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 carbon
deposits in combustion chamber or piston head.

Driving System

Drive Belt
Remove left side cover.
Remove mounting bolt located under air cleaner.
Remove 9 bolts of the engine left side cover and
the cover.
Check if the belt is crack or worn out.
Replace the belt if necessary or in accord with
the periodical maintenance schedule to replace
it.
Width limit: 18.5mm or more
Clutch Pad
Start the motorcycle and gradually increase
throttle valve openness to check clutch pad
operation.
If the motorcycle moves with shaking, then check
its clutch pad for wearing. Replace it if
necessary.
This chapter Contents
Spark plug
2. Maintenance Information
Gear teeth
Clutch pad
Cylinder
pressure
gauge
Width
Clutch
2-9