VESPA LX 150 4T Euro 3 Service Station Manual page 104

Engine
- Remove the central screw and the tensioner
spring. Check that the one-way mechanism is not
worn.
- Check the condition of the tensioner spring.
- If examples of wear are found, replace the whole
unit.
Inspecting the valve sealings
- Measure the width of the sealing surface on the valve seats.
Specification
Intake valve - seal surface
Exhaust valve - seal surface
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
Standard drainage guide diameter
5.012 mm
Standard intake guide diameter
5.012 mm
ENG - 104
Vespa LX 125 - 150 4T Euro 3
VALVE SEAL SURFACE
Desc./Quantity
2.4 - 2.8 mm
2.2 - 2.6 mm