Fuel System Trouble Diagnosis; Poor Engine Start; Stall After Started; Mixture Too Lean - Sym Symply50 Service Manual

SYM
TROUBLE DIAGNOSIS

Poor engine start

No fuel in fuel tank
Clogged fuel tube
Too much fuel in cylinder
No spark from spark plug (malfunction of
ignition system)
Clogged air cleaner
Malfunction of automatic by-starter
Malfunction of throttle valve operation

Stall after started

Malfunction of automatic by-starter
Incorrect ignition timing
Malfunction of carburetor
Dirty engine oil
Air existing in intake system
Incorrect idle speed
Rough idle
Malfunction of ignition system
Incorrect idle speed
Malfunction of carburetor
Dirty fuel
Intermittently misfire as acceleration
Malfunction of ignition system
Late ignition timing
Malfunction of ignition system
Malfunction of carburetor
Power insufficiency and fuel consuming
Fuel system clogged
Malfunction of ignition system

Mixture too lean

Clogged fuel injector
Vacuum piston stick and closed
Malfunction of float valve
Fuel level too low in float chamber
Clogged fuel tank cap vent
Clogged fuel filter
Obstructed fuel pipe
Clogged air vent hose
Air existing in intake system
Mixture too rich
Clogged air injector
Malfunction of float valve
Fuel level too high in float chamber
Malfunction of automatic by-starter
Dirty air cleaner
4. FUEL SYSTEM
4-3