Suzuki UF50, Service Manual

Page: 42 / 185

ENGINE 3-13
ENGINE COMPONENTS INSPECTION
AND SERVICE
CYLINDER HEAD DISTORTION
Decarbonize the combustion chamber.
Check the gasket surface of the cylinder head for distortion. Use
a straightedge and thickness gauge. Take clearance readings at
several places. If readings exceed the service limit, replace or
flatten the cylinder head.
09900-20803: Thickness gauge
Cylinder head distortion
Service Limit: 0.05 mm
Place a sheet of emery paper (about #400 grit) on a surface
plate. Use a figure-eight motion when grinding the cylinder head
surface.
The gasket surface must be smooth and perfectly flat, for a tight
fit. A leaky joint can cause reduced power and increased fuel
consumption.
CYLINDER
Remove carbon from the exhaust port and the upper part of the
cylinder. Take care not to damage the surface of the cylinder
wall.
CYLINDER BORE
Measure the cylinder bore with the cylinder gauge at 20 mm
from the top of the cylinder.
If the measurement exceeds the service limit, rebore the cylin-
der and replace the piston with an oversized piston or replace
the cylinder with a new one. Oversized pistons are available in
two sizes: 0.5 mm and 1.0 mm.
09900-20508: Cylinder gauge set
Cylinder bore
Service Limit: 41.075 mm
Chamfer the port edges after reboring. Use a scraper and take
care not to nick the surface of the walls. Use emery paper (about
#400 grit) to smooth the chamfered edges.
NOTE:
Shallow grooves or minor scuffs can be removed by using em-
ery paper (about #400 grit). If the flaws are deep grooves or
cannot be removed with the emery paper, the cylinder must be
rebored to the next oversize.
1.0 – 1.5 mm
1.0 – 1.5 mm
0.3 – 0.5 mm