Starting Failure/ Hard Starting - Yamaha Libero Workshop Manual

R-203
NOTE:
The following troubleshooting does not cover all the possible causes of trouble. It should be helpful,
however, as a guide to troubleshooting. Refer to the related procedure in this manual for inspection,
adjustment and replacement of parts.
FUEL SYSTEM
Fuel Tank
• Empty
• Clogged Fuel Tank Cap Breather Hole
• Deteriorated fuel or fuel containing water or
foreign material
Fuel Cock
• Clogged Fuel Hose
• Clogged Fuel Cock
Carburetor
• Deteriorated fuel or fuel containing water or
foreign material
• Clogged Pilot Jet
• Clogged air passage
• Improperly set Pilot Screw
• Clogged Pilot air passage
• Improperly sealed Valve Seat
• Improperly adjusted Fuel level
• Clogged Starter Jet
• Damaged Carburetor Joint
• Improperly tightened Carburetor Joint Clamp
Hose
• Starter Plunger malfunction
• Sucked -in air
Air Filter
• Clogged Air Filter element
• Improper Air Filter setting
STARTING FAILURE / HARD STARTING
STARTING FAILURE / HARD STARTING
COMPRESSION SYSTEM
Cylinder and Cylinder Head
• Loose Spark Plug
• Loose Cylinder Head
• Broken Cylinder Head Gasket
• Broken Cylinder Gasket
• Worn, damaged or seized Cylinder
Piston and Piston ring
• Worn Piston
• Worn, Fatigued or broken Piston Rings
• Seized Piston Rings
• Seized or damaged Piston
Valve System
• Improperly adjusted Valve clearance
• Improperly sealed Valve
• Improperly contacted Valve and Valve seat
• Improper Valve timing
• Broken Valve Spring
• Seized Valve
8-1
TRBL
SHTG