VESPA LXV 125, Service Station Manual

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Engine
Poor performance
POOR PERFORMANCE
Possible Cause Operation
Air filter blocked or dirty. 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.
Fuel nozzles or cock clogged or dirty Dismantle, wash with solvent and dry with compressed air
Dirty or faulty vacuum-operated cock Check the filter on the cock, remove the petrol and wash the
tank, if necessary. Replace the cock as a last resource.
Failing automatic starter on the carburettor Check the electrical wiring and mechanical movement, replace
if necessary.
Excessive driving belt wear Check it and replace, if necessary
Lack of compression: parts, cylinder and valves worn Replace the worn parts
Oil level exceeds maximum Check for causes and fill to reach the correct level
Excess of encrustations in the combustion chamber Descale the cylinder, the piston, the head and the valves
Incorrect timing or worn timing system elements Time the system again or replace the worn parts
Muffler obstructed Replace
Inefficient automatic transmission Check the rollers and the pulley movement, replace the dam-
aged parts and lubricate the driven pulley moveable guide with
Montblanc Molybdenum Grease
Wrong valve adjustment Adjust the valve clearance properly
Overheated valves Remove the head and the valves, grind or replace the valves
Valve seat distorted Replace the head assembly
Worn cylinder, Worn or broken piston rings Replace the piston cylinder assembly or just the piston rings
Rear wheel spins at idle
REAR WHEEL ROTATES WITH ENGINE AT IDLE
Possible Cause Operation
Idling rpm too high Adjust the idle speed
Clutch fault Check the springs / clutch masses
Starting difficulties
DIFFICULTY STARTING UP
Possible Cause Operation
Battery flat Check the state of the battery. If it shows signs of sulphation
replace it and bring the new battery into service charging it for
eight hours at a current of 1/10 of the capacity of the battery
itself
Faulty spark plug or incorrect ignition advance Replace the spark plug or check the ignition circuit components
- Engine flooded. Try starting-up with the throttle fully open. If the engine fails to
start, remove the spark plug, dry it and before refitting, make
the motor turn so as to expel the fuel excess taking care to
connect the cap to the spark plug, and this in turn to the ground.
If the fuel tank is empty, refuel and start up.
Incorrect valve sealing or valve adjustment Inspect the head and/or restore the correct clearance
Rpm too low at start-up or engine and start-up system dam-
aged
Check the starter motor and the kick-starter unit
Altered fuel characteristics Drain off the fuel no longer up to standard; then, refill
Vacuum operated cock failure Check that fuel is adequately supplied through the pipe by ap-
plying a vacuum to the suction pipe
LXV 125
Troubleshooting
TROUBL - 37