TROUBLESHOOTING
9-2
Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. 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
3. Ignition coil
• Broken or shorted primary or secondary coil
• Cracked or broken ignition coil
4. Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
EASB29B373
POOR MEDIUM-AND-HIGH-SPEED PER-
FORMANCE
Refer to “STARTING FAILURES” on page 9-1.
Engine
1. Air filter
• Clogged air filter element
Fuel system
1. Fuel pump
• Faulty fuel pump
2. Throttle body
• Defective throttle body
3. ECU
• Faulty ECU
EASB29B374
SHIFTING IS DIFFICULT
Refer to “CLUTCH” on page 5-39.
EASB29B375
SHIFT PEDAL DOES NOT MOVE
Engine
1. Shift shaft
• Bent shift shaft
2. Shift drum and shift forks
• Foreign object in a shift drum groove
• Seized shift fork
• Bent shift fork guide bar
3. Transmission
• Seized transmission gear
• Foreign object between transmission gears
• Improperly assembled transmission
EASB29B376
JUMPS OUT OF GEAR
Engine
1. Shift shaft
• Incorrect shift pedal position
• Improperly returned stopper lever
2. Shift forks
• Worn shift fork
3. Shift drum
• Incorrect axial play
• Worn shift drum groove
4. Transmission
• Worn gear dog
EASB29B377
CLUTCH SLIPS
Engine
1. Clutch
• Improperly assembled clutch
• Loose or fatigued clutch spring
• Worn friction plate
• Worn clutch plate
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (low)
• Deteriorated oil
EASB29B378
CLUTCH DRAGS
Engine
1. Clutch
• Unevenly tensioned clutch springs
• Warped pressure plate
• Bent clutch plate
• Swollen friction plate
• Bent clutch push rod
• Damaged clutch boss
• Burnt primary driven gear bushing
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (high)
• Deteriorated oil
EASB29B379
OVERHEATING
Engine
1. Cylinder head and piston
• Heavy carbon buildup
• Clogged coolant passages
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity
• Inferior oil quality
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...