Incorrect Engine Idling Speed - Yamaha YBR250 2007 Service Manual

INCORRECT ENGINE IDLING SPEED

ELECTRICAL SYSTEMS
Battery
• Discharged battery
• Faulty battery
Fuse(s)
• Incorrect, damaged or blown fuse
• Improperly installed fuse
Spark plug
• Incorrect spark plug type
• Incorrect temperature range
• Rusted spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
Ignition coil
• Cracked or broken ignition coil body
• Broken or shorted primary or secondary coils
• Faulty spark plug lead
INCORRECT ENGINE IDLING
SPEED
ENGINE
Cylinder and cylinder head
• Incorrect valve clearance
• Damaged components in valve system
Air filter
• Clogged air filter element
FUEL SYSTEM
Throttle body
• Damaged or loose throttle body joint
• Engine idling speed improperly adjusted
• Improper throttle cable free play
• Faulty throttle body
• Faulty air induction system
STARTING FAILURES/
Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
Switches and wiring
• Faulty ignition
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Faulty start switch
• Faulty sidestand switch
• Faulty clutch switch
• Improperly grounded circuit
• Loosen connections
Pulling out system
• Faulty starter motor
• Faulty starter relay
• Faulty starter clutch
ELECTRICAL SYSTEMS
Battery
• Discharged battery
• Faulty battery
Spark plug
• 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
• Broken or shorted primary or secondary
coils
• Faulty spark plug lead
• Cracked or broken ignition coil
Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
8-2
TRBL
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SHTG