VESPA LXV 125 Service Station Manual page 38

Troubleshooting
Possible Cause
Failing automatic starter on the carburettor
Start-up enabling buttons failure
Carburettor nozzles clogged or dirty
Air filter obstructed or dirty.
Excessive oil consumption/Exhaust smoke
EXCESSIVE OIL CONSUMPTION/SMOKEY EXHAUST
Possible Cause
Worn valve guides
Worn valve oil guard
Oil leaks from the couplings or from the gaskets
Worn or broken piston rings or piston rings that have not been
fitted properly
Insufficient lubrication pressure
Possible Cause
By-Pass remains open
Oil pump with excessive clearance
Oil filter too dirty
Oil level too low
Engine tends to cut-off at full throttle
THE MOTOR TENDS TO STOP AT MAXIMUM THROTTLE
Possible Cause
Maximum jet clogged
Water or condensate in the carburettor tank
Level in tank too low
Engine tends to cut-off at idle
Possible Cause
Incorrect idle adjustment
Incorrect timing
The starter remains on
Faulty spark plug or incorrect ignition advance
Pressure too low at the end of compression
Minimum nozzle dirty
TROUBL - 38
POOR LUBRICATION PRESSURE
THE ENGINE TENDS TO STOP AT IDLE SPEED
Operation
Check the electrical wiring and mechanical movement, replace
if necessary.
Check continuity using an Ohm meter, with the switch pressed;
replace if necessary
Dismantle, wash with solvent and dry with compressed air
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% of specific oil (Se-
lenia Air Filter Oil), then hand dry without squeezing, allow to
drip dry and then reassemble.
Operation
Check and replace the head unit if required
Replace the valve oil guard
Check and replace the gaskets or restore the coupling seal
Replace the piston cylinder unit or just the piston rings
Operation
Check the By-Pass and replace if required. Carefully clean the
By-Pass area.
Perform the dimensional checks on the oil pump components
Replace the cartridge filter
Restore the level using the recommended oil type (Selenia HI
Scooter 4 Tech)
Operation
Remove the carburettor, wash with solvent and dry with com-
pressed air
Remove the tank, wash with solvent and dry with compressed
Restore the level in the tank by bending on the float the thrust-
ing reed of the petrol inlet rod so as to have the float parallel to
the tank level with the carburettor inverted.
Operation
Adjust using the rpm indicator
Time the system and check the timing system components
Check: electric wiring, circuit not interrupted, mechanical
movement and power supply; replace if necessary
Replace the spark plug or check the ignition circuit components
Check the thermal group seals and replace worn components
Wash the nozzle with solvent and dry with compressed air
LXV 125
air