PIAGGIO MSS X9 EVOLUTION 250, Workshop Manual

Page: 48 / 262

Possible Cause Operation
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 connection and fuel
supply, replace if required.
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.
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 compressed air or re-
place
Battery flat 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 tight-
ened
Defective floating valve Check the proper sliding of the float and the functioning of the
valve
Carburettor nozzles clogged Dismantle, wash with solvent and dry with compressed 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 coupling 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. Carefully 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
Oil level too low Restore the level using the recommended oil type (Selenia HI
Scooter 4 Tech)
Engine tends to cut-off at full throttle
ENGINE STOP FULL THROTTLE
Possible Cause Operation
Faulty fuel supply Check or replace the pump and the vacuum valve, check the
vacuum intake and the pipe sealing
Incorrect float level 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.
Water in the carburettor Empty the tank through the appropriate bleed nipple.
Maximum nozzle dirty - lean mixture Wash the nozzle with solvent and dry with compressed air
Troubleshooting
MSS X9 Evolution 250
TROUBL - 48