APRILIA SR MAX 125 ie Service Station Manual page 20

Characteristics
- If no faults are found during the above checks,
you can use the same valves. To obtain better
sealing performance, grind the valve seats. Grind
the valves gently with a fine-grained lapping com-
pound. During the grinding, keep the cylinder head
with the valve axes in a horizontal position. This
will prevent the lapping compound residues from
penetrating between the valve stem and the guide
(see figure).
CAUTION
TO AVOID SCORING THE FAYING SURFACE, DO NOT KEEP ROTATING THE VALVE WHEN NO
LAPPING COMPOUND IS LEFT. CAREFULLY WASH THE CYLINDER HEAD AND THE VALVES
WITH A SUITABLE PRODUCT FOR THE TYPE OF LAPPING COMPOUND BEING USED.
CAUTION
DO NOT REVERSE THE FITTING POSITIONS OF THE VALVES (RIGHT - LEFT).
- Check that the camshaft bearings exhibit no scores or abnormal wear.
- Using a micrometer, measure the camshaft bearings.
Specification
Bearing A Ø:
Bearing B diameter:
Specification
Bearing A Ø:
Bearing B diameter:
CHAR - 20
STANDARD DIAMETER
MINIMUM ADMISSIBLE DIAMETER
SR MAX 125 ie
Desc./Quantity
37 - 0.025 -0.050 mm
19 - 0.020 -0.041 mm
Desc./Quantity
36.940 mm
19.950 mm