VESPA LX 4T USA, Workshop Manual, Page: 93 / 194

Head lock-nuts (cylinder stud replacement only) 6÷7 N*m + 135° + 90°
The 45° reduction in rotation is necessary to prevent the excessive straining of the studs.
Inspecting the cylinder head
- Using a trued bar check that the cylinder head
surface is not worn or distorted.
- Check that the camshaft and rocking lever pin
bearings show no signs of wear.
- Check that the cylinder head cover surface, the
intake manifold and the exhaust manifold are not
worn.
Characteristic
Maximum admitted unevenness: Head check
0.05 mm
HEAD CHECK
Specification Desc./Quantity
Standard diameter (mm) A Ø 32.015 ÷ 32.025 mm
Standard diameter (mm) B Ø 16.0 ÷ 16.018
Standard diameter (mm) C Ø 11.0 ÷ 11.018
Inspecting the timing system components
- Check that the guide shoe and the tensioner shoe
are not worn out.
- Ensure that the camshaft drive pulley, the chain
assembly and the sprocket wheel are not worn.
- If sings of wear are found, replace the parts. if the
chain, pinion or pulley are worn, replace the whole
assembly.
LX 4T USA
Engine
ENG - 93