PIAGGIO MSS X9 EVOLUTION 250, Workshop Manual

Page: 144 / 262

the valve opens and the depression is suddenly
set to zero.
Lack of tightness or the fact that the valve opens
at different vacuum values should be regarded as
anomalies. In this case, replace it.
N.B.
LACK OF TIGHTNESS IN THE CUT-OFF VALVE RESULTS
IN EXHAUST NOISE (EXPLOSIONS IN THE MUFFLER). IN-
CORRECT CUT-OFF VALVE CALIBRATION CAN RESULT
IN CATALYTIC CONVERTER MALFUNCTIONING
N.B.
A FAULTY CUT-OFF VALVE DIAPHRAGM, BESIDES
JEOPARDISING THE CORRECT OPERATION OF THE
CUT-OFF VALVE, ALSO DAMAGES IDLE FUNCTIONING
Specific tooling
020329Y MityVac vacuum-operated pump
Fuel supply
Removing the carburettor
Kehin
- To detach the carburettor from the engine, it is
necessary to move the air filter and remove the
transmission throttle control, the automatic starter
connection, the clamps anchoring the carburettor
to the filter housing and to the inlet manifold, the
air delivery pipe to the diaphragm, and the intake
fitting.
- Take out the carburettor and rotate it so as to
remove the screw with the water joint and the
pipes.
N.B.
THIS LAST OPERATION IS NECESSARY SO AS NO TO
EMPTY THE COOLING SYSTEM.
Engine
MSS X9 Evolution 250
ENG - 144