Vespa LX 2012 - Page 22

- Measure the diameter of the valve stems in the
three positions indicated in the diagram.
STANDARD DIAMETER
Specification Desc./Quantity
Intake: 4.030 to 4.015 mm
Exhaust: 4.975 to 4.960 mm
- Calculate the clearance between valve and valve guide.
- Check the deviation of the valve stem by resting
it on a «V» shaped support and measuring the ex-
tent of the deformation using a dial gauge.
Characteristic
Limit values admitted:
0.02 mm
- Check the oscillation of the valve head by ar-
ranging a dial gauge at right angle relative to the
valve head and rotate it on a "V" shaped abutment.
Characteristic
Admissible limit:
0.3 mm
Measure the valve guide.
Characteristic
Valve guide:
4.3 ± 0.1 mm
Characteristics Vespa LX - S 125 3V ie 150 3V ie (2012)
CHAR - 22