Sym RS-50 Service Manual page 55

5. CYLINDER HEAD/CYLINDER/PISTON
Place a cleaning cloth onto the crankcase opening
to prevent the piston pin snap ring from falling into
the crankcase.
Apply with two-stroke engine oil onto needle
bearing and piston pin, and then install the piston
pin onto connecting rod. Install piston, and place
"EX" mark of the piston toward to exhaust side.
Install new piston pin snap ring.
Clean all gaskets onto the interfaces of cylinder
and crankcase.
Place a new gasket onto the crankcase.
Make sure that the piston ring aligns with the lock
pin in piston ring groove.
Caution
Make sure that all rings in the piston ring groove
can not be rotated around the lock pin to avoid
to damaging the rings, piston and cylinder.
Lubricate cylinder and piston with two-stroke
engine oil. Hold the piston and then install it into
cylinder.
Caution
To avoid to damaging the piston and the
cylinder sliding surface.
Install the cylinder head.
5-8
This chapter Contents
Piston
Piston pin snap ring
Lock pin
〝EX〞mark
Piston pin