APRILIA Atlantic 300 Service Station Manual page 29

ATLANTIC 300 i.e.
- If no faults are found during the above checks,
the same valves can be reused. For better sealing
results, we recommend grinding the valve seats.
Grind the valves gently with fine-grained lapping
compound. Upon grinding, keep the cylinder head
in 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 ROTATE 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 CHANGE THE VALVE FITTING POSITION (RH - LH).
- Check the camshaft bearings for signs of abnormal wear or scores.
- Using a micrometer, measure the camshaft bearings.
Specification
Camshaft check: Standard diameter
Camshaft check: Standard diameter
Specification
Camshaft check: Minimum diameter admitted
Camshaft check: Minimum diameter admitted
S
TANDARD DIAMETER
M
INIMUM DIAMETER ADMITTED
Desc./Quantity
Bearing A Ø: 36.95 ÷ 36.975 mm
Bearing B Ø: 19.959 ÷ 19.98 mm
Desc./Quantity
Bearing A Ø: 36.94 mm
Bearing B Ø: 19.950 mm
Characteristics
CHAR - 29