Inspecting The Valve Sealings; Inspecting The Valve Housings; Inspecting The Valves - PIAGGIO X7 250ie Service Station Manual

X7 250ie

Inspecting the valve sealings

- Insert the valves into the cylinder head.
- Alternatively check the intake and exhaust
valves.
- 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

- Check the width of the imprint on the valve
seat«V» wear limit max. 1.6 mm.
- 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.
- If the width of the impression on the valve seat or
the diameter of the valve guide exceed the speci-
fied limits, replace the cylinder head.
Characteristic
Valve seat wear Intake guide
limit accepted: 5.022
Valve seat wear Intake guide
Standard diameter: 5.000 ÷ 5.012 mm
Valve seat wear Exhaust guide
Accepted limit 5.022
Valve seat wear Exhaust guide
Standard diameter: 5.000 ÷ 5.012 mm

Inspecting the valves

- Measure the width of the sealing surface on the valve seats and on the valves.
Characteristic
Engine
ENG - 41