Electrical System; Incorrect Engine Idling Speed; Engine; Fuel System - Yamaha CS50 Service Manual

ELECTRICAL SYSTEMS
Battery
• Discharged battery
• Faulty battery
Fuse(s)
• Blown, damaged or incorrect fuse
• Improperly installed fuse
Spark plug(s)
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
Ignition coil(s)
• Cracked or broken ignition coil body
• Broken or shorted primary or secondary coils
• Faulty spark plug lead
Ignition system
• Faulty ignitor unit
• Faulty pickup coil
• Broken generator rotor woodruff key
EAS00847

INCORRECT ENGINE IDLING SPEED

ENGINE

Cylinder(s) and cylinder head(s)
• Incorrect valve clearance
• Damaged valve train components
Air filter
• Clogged air filter element

FUEL SYSTEM

Carburetor(s)
• Faulty starter plunger
• Loose or clogged pilot jet
• Loose or clogged pilot air jet
• Damaged or loose carburetor joint
• Improperly synchronized carburetors
• Improperly adjusted engine idling speed
(throttle stop screw)
• Improper throttle cable free play
• Flooded carburetor
Autochoke unit
• Faulty starter plunger
• Improperly adjusted starter cable
• Faulty ignitor unit
STARTING FAILURE/HARD STARTING /
INCORRECT ENGINE IDLING SPEED
Switches and wiring
• Faulty main switch
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty front, rear or both brake light switches
• Faulty start switch
• Faulty sidestand switch
• Improperly grounded circuit
• Loose connections
Starting system
• Faulty starter motor
• Faulty starter relay
• Faulty starting circuit cut-off relay
• Faulty starter clutch
ELECTRICAL SYSTEMS
Battery
• Discharged battery
• Faulty battery
Spark plug(s)
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
Ignition coil(s)
• Faulty spark plug lead
Ignition system
• Faulty ignitor unit
• Faulty pickup coil
9-2
TRBL
SHTG