PIAGGIO 633929(IT), Руководство по обслуживанию станции, Страница: 55 / 314

Possible Cause Operation
Rpm too low at start-up or engine and start-up
system damaged
Check the starter motor, the system and the torque
limiter
Incorrect valve sealing or valve adjustment Inspect the head and/or restore the correct clear-
ance
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.
Automatic starter failure Check: mechanical movement, electric connec-
tion and fuel supply, replace if required.
Air filter blocked or dirty. Dismantle the sponge, wash with water and sham-
poo, then soak it in a mixture of 50% petrol and
50% of specific oil (Selenia Air Filter Oil), then
hand dry without squeezing, allow to drip dry and
then reassemble.
Faulty spark plug or incorrect ignition advance Replace the spark plug or check the ignition circuit
components
The carburettor is dirty; fuel pump or vacuum valve
damaged
Remove, wash with solvent and dry with com-
pressed air or replace
Flat battery Check the charge of the battery, if there are any
sulphur marks, replace and use the new battery
following the instructions shown in the chapter
Intake coupling cracked or clamps incorrectly
tightened
Replace the intake coupling and check the clamps
are tightened
Defective floating valve Check the proper sliding of the float and the func-
tioning of the valve
Carburettor nozzles clogged Dismantle, wash with solvent and dry with com-
pressed air
Excessive oil consumption/Exhaust smoke
EXCESSIVE OIL CONSUMPTION/SMOKEY EXHAUST
Possible Cause Operation
Worn valve guides Check and replace the head unit if required
Worn valve oil guard Replace the valve oil guard
Oil leaks from the couplings or from the gaskets Check and replace the gaskets or restore the cou-
pling seal
Worn or broken piston rings or piston rings that
have not been fitted properly
Replace the piston cylinder unit or just the piston
rings
Insufficient lubrication pressure
POOR LUBRICATION PRESSURE
Possible Cause Operation
By-Pass remains open Check the By-Pass and replace if required. Care-
fully clean the By-Pass area.
Oil pump with excessive clearance Perform the dimensional checks on the oil pump
components
Oil filter too dirty Replace the cartridge filter
MP3 125
Troubleshooting
TROUBL - 3