Cylinder Head - HYOSUNG WOW90 Service Manual

ENGINE 3-20
◉ DRIVEN FACE PIN AND OIL SEAL
Turn the driven faces and check to see that the driven
faces turn smoothly.
If any stickness or hitches are found, visually inspect
the lip of seal, driven face sliding surface and sliding
pins for wear or damage.
◉ DRIVEN FACE
Inspect the belt contacting surface of both driven faces
for any scratches, wear and damage.
Replace driven face with new one if there are any
abnormality.

CYLINDER HEAD

Decarbon the combustion chamber.
Check the gasketed surface of the cylinder head for
distortion with a straightedge and thickness gauge,
taking a clearance reading at several places.
Service limit
Cylinder head
distortion
0.05 mm (0.002 in)
Thickness gauge : 09900-20806
If the largest reading at any portion of the straight-
edge exceeds the limit, rework the surface by rubbing
it against emery paper (of about #400) laid flat on the
surface plate in a lapping manner. The gasketed sur-
face must be smooth and perfectly flat in order to
secure a tight joint : a leaky joint can be the cause of
reduced power output and increased fuel consump-
tion.