Valve Stem Replacement - Sym GTS 250 Service Manual

6. Cylinder Head / Valve

Valve Stem Replacement

Heat up cylinder head to 100~150 ¢ J
plate or toaster.
Caution
Do not let torch heat cylinder head directly.
Otherwise, the cylinder head may be deformed
as heating it.
Wear on a pair of glove to protect your hands
when operating.
Hold the cylinder head, and then press out old
valve guide from combustion chamber side.
Tool: Valve guide driver: 5.0 mm
Caution
Check if new valve guide is deformation after
pressed it in.
When pressing in the new valve guide, cylinder
head still have to be kept in 100~150
Adjust the valve guide driver and let valve guide
height is in 13 mm.
Press in new valve guide from rocker arm side.
Tool: Valve guide driver: 5.0 mm
Wait for the cylinder head cooling down to room
temperature, and then correct the new valve guide
with reamer.
Caution
Using cutting oil when correcting valve guide
with a reamer.
Turn the reamer in same direction when it be
inserted or rotated.
Correct valve seat, and clean up all metal residues
from cylinder head.
Tool: Valve guide reamer: 5.0 mm
6-10
To this chapter contents
with heated
.
¢ J
Valve guide driver
5.0mm
Valve guide reamer 5.0 mm
Valve guide driver
5.0 mm