Cylinder; Piston - HYOSUNG Prima Service Manual

3-19 ENGINE
If the largest reading at any portion of the straightedge
exceeds the limit, rework the surface by rubbing it
against emery paper (of about # 400) laid flat on the sur-
face plate in a lapping manner. The gasketed surface
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 consumption.

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 20 mm 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 gauge set : 09900 - 20508
Cylinder bore
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 15 mm
from the skirt end.
Micrometer(25~50 mm) : 09900 - 20202
Piston diameter
Service limit 41.070 mm
Service limit 40.885 mm