TROUBLESHOOTING
9-1
EASB29B369
TROUBLESHOOTING
EASB29B370
GENERAL INFORMATION
TIP
The following guide for troubleshooting does
not cover all the possible causes of trouble. It
should be helpful, however, as a guide to basic
troubleshooting. Refer to the relative procedure
in this manual for checks, adjustments, and re-
placement of parts.
EASB29B371
STARTING FAILURES
Engine
1. Cylinder and cylinder head
• Loose spark plug
• Loose cylinder head or cylinder
• Damaged cylinder head gasket
• Damaged cylinder gasket
• Worn or damaged cylinder
• Incorrect valve clearance
• Improperly sealed valve
• Incorrect valve-to-valve-seat contact
• Incorrect valve timing
• Faulty valve spring
• Seized valve
2. Piston and piston ring(s)
• Improperly installed piston ring
• Damaged, worn or fatigued piston ring
• Seized piston ring
• Seized or damaged piston
3. Air filter
• Improperly installed air filter
• Clogged air filter element
4. Crankcase and crankshaft
• Improperly assembled crankcase
• Seized crankshaft
Fuel system
1. Fuel tank
• Empty fuel tank
• Clogged fuel tank breather hose
• Deteriorated or contaminated fuel
• Clogged or damaged fuel hose
2. Fuel pump
• Faulty fuel pump
3. Throttle body
• Deteriorated or contaminated fuel
• Sucked-in air
Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Fuse
• Blown, damaged or incorrect fuse
• Improperly installed fuse
3. Spark plug
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
4. Ignition coil
• Cracked or broken ignition coil body
• Broken or shorted primary or secondary
coils
5. Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
6. Switches and wiring
• Faulty ECU
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Improperly grounded circuit
• Loose connections
7. Starting system
• Faulty starter motor
• Faulty starter relay
• Faulty starting circuit cut-off relay
• Faulty starter clutch
EASB29B372
INCORRECT ENGINE IDLING SPEED
Engine
1. Cylinder and cylinder head
• Incorrect valve clearance
• Damaged valve train components
2. Air filter
• Clogged air filter element
Fuel system
1. Throttle body
• Damaged or loose throttle body joint
• Improperly synchronized throttle bodies
• Improper throttle cable free play
• Flooded throttle body
Содержание YZ 2018 Series
Страница 6: ...EASB916006 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Страница 10: ......
Страница 40: ...MOTORCYCLE CARE AND STORAGE 1 28...
Страница 51: ...ELECTRICAL SPECIFICATIONS 2 10 Fuse s Main fuse 15 0 A Spare fuse 15 0 A Radiator fan motor fuse 5 0 A...
Страница 64: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 23...
Страница 66: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25...
Страница 67: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 26 1 Exhaust camshaft 2 Intake camshaft 3 Oil filter element 4 Oil pump...
Страница 68: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27...
Страница 69: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 28 1 Camshaft 2 Oil pressure check bolt 3 Oil filter element 4 Oil pump...
Страница 70: ...CABLE ROUTING DIAGRAM 2 29 EASB29B065 CABLE ROUTING DIAGRAM...
Страница 72: ...CABLE ROUTING DIAGRAM 2 31...
Страница 74: ...CABLE ROUTING DIAGRAM 2 33...
Страница 76: ...CABLE ROUTING DIAGRAM 2 35...
Страница 78: ...CABLE ROUTING DIAGRAM 2 37...
Страница 80: ...CABLE ROUTING DIAGRAM 2 39...
Страница 82: ...CABLE ROUTING DIAGRAM 2 41...
Страница 84: ...CABLE ROUTING DIAGRAM 2 43...
Страница 235: ...ELECTRIC STARTER 5 38 5 Install Bolt 1 O ring 2 TIP Apply the lithium soap based grease on the O ring New...
Страница 255: ...OIL PUMP AND BALANCER GEAR 5 58 a 2 10 b 2 9 1 b 5 3 a 4 10 5 9 3 E c d 6 7 8 8 b 6...
Страница 276: ...TRANSMISSION 5 79...
Страница 290: ...FUEL TANK 7 5 A Left B Right 1 1 A 0 mm 0 in B 1 1 15 mm 0 59 in...
Страница 296: ...THROTTLE BODY 7 11...
Страница 299: ......
Страница 313: ...CHARGING SYSTEM 8 14...
Страница 321: ...COOLING SYSTEM For JPN 8 22...
Страница 351: ...FUEL PUMP SYSTEM 8 52 EASB29B345...
Страница 352: ...ELECTRICAL COMPONENTS 8 53 ELECTRICAL COMPONENTS EASB29B346 9 10 11 1 3 2 4 5 6 7 8...
Страница 354: ...ELECTRICAL COMPONENTS 8 55 11 10 9 2 3 1 6 7 8 4 5...
Страница 356: ...ELECTRICAL COMPONENTS 8 57 EASB29B347 CHECKING THE SWITCHES 4 1 3 2 B B Sb B B B B B B B B...
Страница 357: ...ELECTRICAL COMPONENTS 8 58 1 Engine stop switch 2 Neutral switch 3 Clutch switch 4 Start switch...
Страница 372: ...ELECTRICAL COMPONENTS 8 73 c Measure the fuel injector resistance...