APRILIA Atlantic 300 Service Station Manual page 26

Characteristics
- Check that the coolant sealing buffer is not rusted.
Measure the camshaft seat bearings and rocking
lever support pins with a bore meter
Specification
bearing «A»
bearing «B»
bearing «C»
Measure the unloaded spring length
Characteristic
Standard length
40.2 mm
Limit allowed after use
38.2 mm
- Remove any carbon deposits from the valve
seats.
- Check the width of the mark on the valve seat
«V» with Prussian blue.
Characteristic
Standard value:
1 - 1.3 mm
Limit allowed:
1.6 mm
- If the width of the mark on the valve seat is larger than the prescribed limits, true the seats with a 45°
milling cutter and then grind.
- Replace the head in case of excessive wear or damage.
Specification
Valve check: standard length
Valve check: standard length
CHAR - 26
HEAD BEARINGS
S
TANDARD LENGTH OF VALVE
ATLANTIC 300 i.e.
Desc./Quantity
Ø 12.000 ÷ 12.018
Ø 20.000 ÷ 20.021
Ø 37.000 ÷ 37.025
Desc./Quantity
Inlet: 94.6 mm
Outlet: 94.4 mm