Checking The Cylinder Head - APRILIA MSS Mana GT ABS Service Station Manual

MSS Mana GT ABS
- After measuring the valve guide diameter and the
valve stem diameter, check the clearance be-
tween guide and stem.
Specification
Standard clearance:
Limit allowed:
Specification
Standard clearance:
Limit allowed:
See also
Installing the
cylinder head

Checking the cylinder head

Clean all the coupling surfaces thoroughly before servicing the head. Pay attention to the position of
the springs and valves so as not to change the original position upon refitting them
- Using a trued bar and a thickness gauge, check
that the cylinder head surface is not worn or dis-
torted.
Characteristic
Maximum run-out allowed:
0.1 mm
- In case of irregularities, replace the head.
- Check the sealing surfaces for the inlet and exhaust manifold.
- Check that the camshaft and the rocker pin bearings show no signs of wear.
- Check that the head cover show no signs of wear.
- Check that the coolant sealing buffer is not rusted.
EXHAUST
INTAKE
Desc./Quantity
0.025 - 0.052 mm
0.09 mm
Desc./Quantity
0.013 ÷ 0.04 mm
0.08 mm
ENG - 189
Engine