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Possible Cause
Operation
spark plug and the spark plug grounded but away from its hole.
Refit a dry spark plug and start the vehicle.
Altered fuel characteristics
Drain off the fuel no longer up to standard; then, refill
Faulty spark plug
Remove the encrustation, restore the plug gap or replace being
sure to use the types of spark plug recommended at all times.
Bear in mind that many problems engines have, derive from
the use of the wrong spark plug
Intake joint cracked or with a bad seal
Replace intake joint and check for correct sealing on the head
Purifier-carburettor fitting damaged
Replace
Excessive oil consumption/Exhaust smoke
EXCESSIVE OIL CONSUMPTION/SMOKEY EXHAUST
Possible Cause
Operation
Excess of encrustations in the combustion chamber
Remove the encrustations
Engine tends to cut-off at full throttle
ENGINE STOP FULL THROTTLE
Possible Cause
Operation
Maximum nozzle dirty - lean mixture
Wash the nozzle with solvent and dry with compressed air
Dirty carburettor
Wash the carburettor with solvent and dry with compressed air
Water in the carburettor
Empty the tank through the appropriate bleed nipple.
Air filter dirty
Clean or replace
Defective floating valve
Check the proper sliding of the float and the functioning of the
valve
Tank breather hole obstructed
Restore the proper tank aeration
Engine tends to cut-off at idle
ENGINE STOP IDLING
Possible Cause
Operation
Minimum nozzle dirty
Wash the nozzle with solvent and dry with compressed air
Starter that stays open
Check: electric wiring, circuit continuity, mechanical sliding and
power supply
Reed valve does not close
Check / replace the reed pack
Wrong idling adjustment
Adequately adjust the engine idle speed
Spark plug defective or faulty
Replace the spark plug with one with the specified degree and
check the plug gap
Excessive exhaust noise
INCREASED NOISINESS
Possible Cause
Operation
Secondary metal air pipe deteriorated
Check there are no leaks on the hoses on the crankcase and
the housing, check that there is a cap with filter and it is correctly
fitted to the transmission cover
Good condition of the missing secondary air circuit components
Check the individual components and the piping, check the
precision of the fitting. Replace the damaged components
Troubleshooting
Vespa S 50 2T
TROUBL - 40
Summary of Contents for 664787
Page 1: ...SERVICE STATION MANUAL 664787 664795 IT EN FR DE ES PT NL EL Vespa S 50 2T ...
Page 4: ......
Page 6: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 16: ...INDEX OF TOPICS TOOLING TOOL ...
Page 27: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 38: ...INDEX OF TOPICS TROUBLESHOOTING TROUBL ...
Page 44: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 48: ...Conceptual diagrams Ignition Electrical system Vespa S 50 2T ELE SYS 48 ...
Page 64: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 66: ...INDEX OF TOPICS ENGINE ENG ...
Page 97: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 117: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 126: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 136: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 140: ...INDEX OF TOPICS TIME TIME ...
Page 169: ...Seat SADDLE Code Action Duration 1 004003 Saddle Replacement Vespa S 50 2T Time TIME 169 ...