Cylinder; Piston - HYOSUNG WOW90 Service Manual

3-21 ENGINE

CYLINDER

Decarbon exhaust port and upper part of the cylinder,
taking care not to damage the cylinder wall surface.
The wear of the cylinder wall is determined from diame-
ter reading taken at 20mm from the top of the cylinder
with a cylinder gauge. If the wear thus determined
exceeds the limit indicated below, rework the bore to the
next oversize by using a boring machine or replace the
cylinder with a new one.
Cylinder bore
Cylinder gauge set : 09900-20508
After reworking the bore to an oversize, be sure to
chamfer the edges of ports and smooth the chamfered
edges with emery paper. To chamfer, use a scraper,
taking care not to nick the wall surface.

PISTON

◉ CYLINDER TO PISTON CLEARANCE
Cylinder-to-piston clearance is the difference between
piston diameter and cylinder bore diameter. Be sure to
take the maked diameter at right angles to the piston
pin. The value of elevation � is prescribed to be 20mm
from the skirt end.
Micrometer(50 ~ 75mm) : 09900-20203
Piston diameter
Service limit
52.590 mm (2.071 in)
Service limit
52.332 mm (2.060 in)