Checking The Spark Advance - VESPA PX 150 USA Workshop Manual

Maintenance
Carburettor
Disassemble the carburetor and clean all compo-
nents with solvent, hence dry with compressed air
all ducts, in order to ensure proper cleaning.
•
Carefully check the state of each com-
ponent.
•
The throttle valve must be free to slide
inside the mixture chamber; replace if
excessive play is found.
•
If the mixture chamber is excessively
worn, such to prevent the sliding of the
throttle valve (although new), replace
the carburetor.
•
All seals should be replaced upon re-
assembly.
Specification
Conical needle
Emulsifier air adjusting screw
Emulsifier
Main jet
Slow-running jet
Fuel flow adjusting screw
Throttle valve adjusting screw
Throttle valve
Starter jet
Choke device

Checking the spark advance

In order to ensure the correct timing, check the
stator is oriented so that the I.T. index (see figure)
coincides with the marking found on the crank-
case.
− To check the timing, use a timing light, connect-
ing it to the H.T. cable via the clip provided and
then starting the engine.
− The correct spark advance is obtained when,
with the engine running between 2,500 and 3,000
rpm, the «P» index is aligned (±1°) with the I.T.
marking stamped on the volute.
MAIN - 28
CARBURETOR
Float
Vespa PX 150 USA
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