Inspecting The Valve Housings - PIAGGIO MSS Fly 50 4T Workshop Manual

Engine
1.6 mm
- Insert the valves into the cylinder head.
- Test the 2 valves alternatively.
- The test is carried out by filling the manifold with
petrol and checking that the head does not ooze
through the valves when these are just pressed
with the fingers.

Inspecting the valve housings

- Remove any carbon formation from the valve
guides.
- Measure the inside diameter of each valve guide.
- Take the measurement at three different heights
in the rocker arm push direction.
Characteristic
Discharge guide: Standard diameter
5 +0+0.012mm
Discharge guide: Wear limit
5.022 mm
Intake guide: Standard diameter
5 +0+0.012mm
Intake guide: Wear limit
5.022 mm
- If the width of the impression on the valve seat or the diameter of the valve guide exceed the specified
limits, replace the cylinder head.
- Check width of the impression on the valve seat «V»
Characteristic
Wear limits:
Max. 1.6 mm.
ENG - 96
MSS Fly 50 4T