Possible Cause
Operation
Oil pump with excessive clearance
Perform the dimensional checks on the oil pump
components
Oil filter too dirty
Replace the cartridge filter
Oil level too low
Restore the level adding the recommended oil
type
Engine tends to cut-off at full throttle
THE MOTOR TENDS TO STOP AT MAXIMUM THROTTLE
Possible Cause
Operation
Level in tank too low
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.
Tank breather hole obstructed
Restore the proper tank aeration
Fuel supply pipes choked or clogged
Restore the adequate fuel supply
Maximum nozzle dirty - lean mixture
Wash the nozzle with solvent and dry with com-
pressed air
Water in the carburettor
Empty the tank through the appropriate bleed nip-
ple.
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.
Faulty fuel supply
Check or replace the fuel pump, and check the
vacuum intake and the pipe sealing
Engine tends to cut-off at idle
THE ENGINE TENDS TO STOP AT IDLE SPEED
Possible Cause
Operation
Air calibrated holes in carburettor blocked
Dismantle, wash with solvent and dry with com-
pressed air
Defective floating valve
Check the proper sliding of the float and the func-
tioning of the valve
Level in chamber too high
Restore the level of the float chamber bending on
the float the thrusting reed of the petrol inlet pin so
as to have the float parallel to the float chamber
level, with the carburettor inverted.
The starter remains on
Check the electric connection, fuel supply and me-
chanical movement. Replace if required.
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 timing
Time the system and check the timing system
components
Cut off device failure
Check that the following parts work properly:
valve; diaphragm; spring; and that the air calibra-
tion elements are clean; check if the sponge filter
is clean too
Incorrect idle adjustment
Adjust using the rpm indicator
Troubleshooting
Vespa GTV 125
TROUBL - 4
Summary of Contents for GTV 125
Page 4: ......
Page 6: ......
Page 7: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 20: ...Characteristics Vespa GTV 125 CHAR 14 ...
Page 21: ...INDEX OF TOPICS TOOLING TOOL ...
Page 34: ...Tooling Vespa GTV 125 TOOL 14 ...
Page 35: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 57: ...INDEX OF TOPICS TROUBLESHOOTING TROUBL ...
Page 64: ...Troubleshooting Vespa GTV 125 TROUBL 8 ...
Page 65: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 89: ... Refit the battery cover Vespa GTV 125 Electrical system ELE SYS 25 ...
Page 90: ...Electrical system Vespa GTV 125 ELE SYS 26 ...
Page 91: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 98: ...Engine from vehicle Vespa GTV 125 ENG VE 8 ...
Page 99: ...INDEX OF TOPICS ENGINE ENG ...
Page 156: ...Engine Vespa GTV 125 ENG 58 ...
Page 167: ... Remove the maximum nozzle Remove diffuser Vespa GTV 125 Engine ENG 69 ...
Page 177: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 199: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 215: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...
Page 221: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 237: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 241: ...INDEX OF TOPICS TIME TIME ...