Head Check; Checking The Valve Sealing Surfaces - PIAGGIO 500 cc Service Manual

Head check

- Check that the head surface shows no signs of wear
or deformations by means of a ground bar and a
feeler gauge.
Maximum allowed runout: 0.1 mm
- In case of troubles, replace the head.
- Check the sealing surface of the intake and exhaust
manifold.
- Check that the camshaft and equalizer pin supports
show no signs of wear.
- Check that the head cover surface shows no signs of
wear.
- Check that the coolant sealing pad shows no signs of
oxidation.
Standard diameter
A
B
C
- If worn, also check the corresponding component
when the head is replaced

Checking the valve sealing surfaces

- Visually check the valves sealing surfaces.
Warning
- Do not change the valves assembly
position (RH-LH).
- If the valve sealing surface is discontinued in one or
more points, or if it is bent, replace the valve.
13 + 0.018
0
+ 0.021
20
0
+ 0.025
42
0
Thermal unit and timing system
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05_198
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