VESPA GTV 250 i.e. 2008 Service Station Manual page 128

Engine
Inspecting the timing system components
- Check that the guide slider and the tensioner
slider are not worn out.
- Ensure that the camshaft control pulley chain as-
sembly and the sprocket wheel are not worn.
- If you detect wear, replace the parts or, if the
chain, sprocket wheel and pulley are worn, replace
the whole unit
- Remove the centre screw with the washer 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
- 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.
ENG - 128
Vespa GTV 250 i.e.