Yamaha YW50P Service Manual page 205

ITRBLI
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I
S T A R T I N G FAILURE/HARD S T A R T I N G
ISHTGI I
I G N I T I O N S Y S T E M PROBABLE C A U S E
Spark plug
Ignition coil
CD I unit system
• Improper plug gap
• Worn electrodes
• Wire between terminals broken
• Improper heat range
• Faulty spark plug cap
Switches and wiring
L • Broken or shorted primary/secondary coil
• Faulty spark plug lead
• Broken body
• Faulty CD I unit
L • Faulty source coil
• Faulty pick-up coil
• Faulty main switch
/
L • Broken or shorted wiring
C O M P R E S S I O N S Y S T E M PROBABLE C A U S E
Cylinder and cylinder head
Piston and piston rings
Crankcase and crankshaft
L"
L
•
/"
Loose spark plug
Loose cylinder head or cylinder
Broken cylinder head gasket
Broken cylinder gasket
Worn, damaged or seized cylinder
Improperly installed piston ring
Worn, fatigued or broken piston ring
Seized piston ring
Seized or damaged piston
Improperly seated crankcase
Improperly sealed crankcase (Damaged oil
seal)
Seized crankshaft
Reed valve • Deformed reed valve stopper
• Improperly seated read valve
• Loose intake manifold
• Broken gasket
• Broken reed valve
8-2