VESPA LX 150 4T Euro 3 Service Station Manual page 130

Engine
With the multimeter, check if the potentiometer is
working correctly by placing the probes on both
contactors indicated in the photograph .
With throttle valve completely closed, the resist-
ance value should be approx. 1.3 kOhm.
With throttle valve completely open, the resistance
value should be approx. 4.05 kOhm.
- Disconnect the fuel supply and the suction taking
pipe from the carburettor.
- Check that there are no fuel leaks between the
two tubes.
- Close the fuel outlet pipe.
- By means of the MITYVAC pump apply 0.1 bar
of suction to the tap.
- Make sure that the suction is kept stable and that
and that there are no fuel leaks.
- Reconnect the vacuum pipe to the manifold.
- Position the fuel pipe with the outlet at the point
of the tap.
- Turn the engine by using the starter motor for five
seconds with the carburettor at minimum.
- Take up the fuel by means of a graded burette.
N.B.
THE MEASUREMENT MAY BE FALSIFIED BY THE INCOR-
RECT NUMBER OF REVS OR BY THE WRONG POSITION
OF THE TUBE. IN THIS CASE, THE TENDENCY IS TO OB-
TAIN A REDUCED FUEL FLOW RATE. THE SUCTION OUT-
LET ON THE MANIFOLD HAS A SECTION INTENTIONALLY
REDUCED FOR THE PURPOSE OF ENHANCING THE SUC-
TION PULSATION AND THEREBY GUARANTEE A CON-
STANT TAP FLOW RATE.
Specific tooling
020329Y Mity-Vac vacuum-operated pump
Characteristic
Minimum flow rate
20 cc
ENG - 130
Vespa LX 125 - 150 4T Euro 3