VESPA LX 4T USA, Workshop Manual

Page: 120 / 194

- Refit the carburettor on the engine and connect
again the accelerator cable with the sheath and the
support plate and the electrical connection of the
starter.
- Reconnect the fuel supply pipe and tighten the 2
clamping screw fixing the carburettor to the inlet
manifold and the air inlet coupling to the filter.
Adjusting the idle
- The engine does not require frequent idle speed adjustments, but it is essential to strictly follow certain
rules when adjusting the idle speed.
- Before adjusting the carburettor make sure to respect requirements on lubrication, valve clearance,
and complying timing; spark plug should be in optimum conditions, air filter clean and sealed, and the
exhaust system tight.
- Warm up the engine by running it at least 10 mi-
nutes at a speed as close as possible to the max-
imum one.
- Connect the vehicle to the exhaust fumes analy-
ser inserting the probe into a sealed extension pipe
placed at the muffler exit end.
N.B.
THE EXTENSION TUBE IS INDISPENSABLE SO AS NOT
TO SEND POLLUTED EXHAUST FUMES TO THE AMBIENT
OXYGEN. IT IS ESSENTIAL TO USE AN EXHAUST FUMES
ANALYSER PREVIOUSLY HEATED AND PREPARED TO
GUARANTEE THE RESET OF THE READING OF GASES
AND THE CORRECT GAS CAPACITY. FAILURE TO RE-
SPECT THESE REGULATIONS RESULTS IN INACCURATE
READINGS.
Characteristic
Pipe ideal length
40 ÷ 50 cm
Engine
LX 4T USA
ENG - 120