Suzuki DF 25, Service Manual, Page: 89 / 148

POWER UNIT 6-23
CYLINDER / PISTON / PISTON RING
Cylinder distortion
Using a straightedge and the thickness gauge, measure the
gasket surface of the cylinder at a total of six locations as shown
in the figure.

09900-20803: Thickness gauge
Cylinder distortion:
Service limit: 0.05 mm (0.002 in)
If the measurement exceeds the service limit, resurface or
replace the cylinder.
NOTE:
The cylinder can be resurfaced, using a surface plate and a
#400 grit wet sandpaper.
Move the cylinder in a figure eight pattern when sanding.
Water jacket
Inspect the water jackets for clog or obstruction.
Clean the water jackets if necessary.
Cylinder bore
Inspect the cylinder wall for scratches, roughness or ridges
which indicate excessive wear.
If the cylinder bore is very rough or deeply scratched or ridged,
rebore the cylinder and use a oversize piston.
Cylinder bore wear (difference)
Using the cylinder bore gauge, measure the cylinder bore in the
thrust and axial directions at the three positions
A
,
B
and
C
.

09900-20530: Cylinder gauge set
Check for the followings.
• Difference between the measurements at the three positions
(taper).
• Difference between the thrust and axial measurements
(out-of-round).
Cylinder bore wear (difference):
Service limit: 0.100 mm (0.0039 in)
If the wear (difference) exceeds the service limit, rebore or
replace the cylinder.