Yamaha 2008 YW50X Service Manual page 253

ITRBLI
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STARTnNG FAnLURE/HARD STARTnNG ISHTGI I
N O T E :
T R O U B L E S H O O T I N G
The f o l l o w i n g t r o u b l e s h o o t i n g does not cover all the possible causes of trouble. It should be
helpful, however, as a guide to t r o u b l e s h o o t i n g . Refer to the relative procedure in this manual for
inspection, a d j u s t m e n t and replacement of parts.
S T A R T I N G F A I L U R E / H A R D S T A R T I N G
FUEL S Y S T E M P R O B A B L E C A U S E
F u e l t a n k
F u e l c o c k
• E m p t y
• Clogged fuel filter
• Deteriorated fuel or fuel containing w a t e r or
foreign material
• Clogged fuel tank cap
L • C l o g g e d fuel hose
• Clogged fuel cock
• Faulty fuel cock operation
• Broken or disconnected fuel cock
Carburetor
A u t o choke
Air cleaner
/ -
• Deteriorated fuel, fuel c o n t a i n i n g w a t e r or
foreign material
• Clogged pilot jet
• Clogged pilot air passage
• Sucked-in air
• Deformed float
• G r o o v e - w o r n needle valve
• I m p r o p e r l y sealed valve seat
• I m p r o p e r l y adjusted fuel level
• I m p r o p e r l y set pilot jet
• Clogged starter jet
Starter plunger malfunction
W a x malfunction
Faulty t h e r m i s t e r
• Clogged air filter
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