VESPA GTV 125, Service Station Manual

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Possible Cause Operation
Pressure too low at the end of compression Check the thermal group seals and replace worn
components
Faulty spark plug or incorrect ignition advance Replace the spark plug or check the ignition circuit
components
The starter remains on Check: electric wiring, circuit not interrupted, me-
chanical movement and power supply; replace if
necessary
Minimum nozzle dirty Wash the nozzle with solvent and dry with com-
pressed air
High fuel consumption
HIGH FUEL CONSUMPTION
Possible Cause Operation
Loose nozzles Check the maximum and minimum nozzles are
adequately fixed in their fittings
Fuel pump failure Check the low-pressure duct sealing
Inefficient Starter Check: electric wiring, circuit continuity, mechani-
cal sliding and power supply
Air filter blocked or dirty Remove the sponge, wash with water and car
shampoo, then soak it in a mixture of 50% petrol
and 50% specific oil. Press with your hand without
squeezing, allow it to drip dry and refit.
Incorrect float level Restore the level in the tank by bending on the float
the thrusting reed of the petrol inlet rod so as to
have the float parallel to the tank level with the
carburettor inverted.
Transmission and brakes
Clutch grabbing or performing inadequately
IRREGULAR CLUTCH PERFORMANCE OR SLIPPAGE
Possible Cause Operation
Faulty clutch Check that there is no grease on the masses.
Check that the clutch mass contact surface with
the casing is mainly in the centre with equivalent
characteristics on the three masses. Check that
the clutch casing is not scored or worn in an anom-
alous way
Insufficient braking
INEFFICIENT BRAKING SYSTEM
Possible Cause Operation
Inefficient braking system Check the pad wear (1.5 min). Check that the
brake discs are not worn, scored or warped. Check
the correct level of fluid in the pumps and replace
brake fluid if necessary. Check there is no air in
Vespa GTV 125
Troubleshooting
TROUBL - 5