APRILIA SHIVER 900 Service Station Manual page 254

Engine
Checking the cylinder
•
All seal surfaces must be clean and flat.
•
Make sure all threads are in proper conditions.
•
Check cylinder sliding surface for signs of friction and scratches. Also check the seal sur-
faces for damages.
CAUTION
IF THE GROOVES ON THE CYLINDER LINER ARE EVIDENT, REPLACE THE CYLINDER AND
THE PISTON.
•
Clean off lime scales on the cylinder
cooling slots.
•
Measure the cylinder bore at a dis-
tance of 10 - 40 - 98.5 mm (0.39 - 1.57
- 3.88 in) from the head coupling sur-
face; the highest value should be con-
sidered to estimate wear limits.
Cylinder bore "C": 92,000 mm (3.6220 in)
(Key: C = max D1 or D2)
Cylindricity limit: 0.028 mm (0.0011 in)
Replace the cylinder, the piston and the piston ring
all together if not complying with specifications.
Checking the piston
•
Measure the piston skirt diameter "P"
with a micrometer (a=10 mm (0.39 in)
from the piston lower border).
•
Calculate the clearance between pis-
ton and cylinder as follows:
Piston - cylinder clearance C = C - P
Piston - cylinder clearance: 0.050 - 0.064 mm
(0.00197 - 0.00252 in) Limit: 0.100 mm (0.00039
in)
•
Replace the cylinder, the piston and
the piston ring all together if not com-
plying with specifications.
ENG - 254
SHIVER 900