Suzuki DF 90 Service Manual page 189

6-44 POWER UNIT
Cylinder bore
Inspect cylinder walls for scratches, roughness, or ridges which
indicate excessive wear.
If cylinder bore is very rough or deeply scratched, or ridged,
rebore cylinder and use oversize piston.
Cylinder bore wear (difference)
Using cylinder gauge, measure cylinder bore in both axial (ver-
tical line, following crankshaft) and transverse (horizontal line
across crankshaft) directions at two positions as shown in fig-
ure.
09900-20530 : Cylinder gauge set
Check for following :
• Difference between measurements at the two positions
(taper).
• Difference between axial and transverse measurement (out-
of-round).
Cylinder bore wear (difference) :
Service limit : 0.100 mm (0.0039 in.)
If measurement exceeds service limit, rebore or replace cylin-
der.
PISTON TO CYLINDER CLEARANCE
1. Measure piston diameter at a point 26.5 mm (1.04 in.) above
piston skirt at a right angle to piston pin bore.
09900-20204 : Micrometer
Piston skirt diameter :
Standard : 83.970 – 83.990 mm (3.3059 – 3.3067 in.)
2. Measure cylinder bore at 50 mm (2.0 in.) below cylinder
head gasket surface at a right angle to crankshaft pin.
09900-20530 : Cylinder gauge set
Cylinder bore :
Standard : 84.000 – 84.020 mm (3.3071 – 3.3079 in.)
1
2
1. 50 mm (1.96 in.)
2. 90 mm (3.54 in.)
50 mm
26.5 mm