TROUBLESHOOTING
9-3
Fuel system
1. Throttle body
•
Damaged or loose throttle body joint
2. Air filter
•
Clogged air filter element
Chassis
1. Brake(s)
•
Dragging brake
Electrical system
1. Spark plug
•
Incorrect spark plug gap
•
Incorrect spark plug heat range
2. Ignition system
•
Faulty ECU
•
Faulty coolant temperature sensor
EAM30319
OVERCOOLING
Cooling system
1. Coolant temperature sensor
•
Faulty coolant temperature sensor
EAM30320
POOR BRAKING PERFORMANCE
Chassis
1. Brake(s)
•
Worn brake pad
•
Worn brake disc
•
Air in hydraulic brake system
•
Leaking brake fluid
•
Defective master cylinder kit
•
Faulty brake caliper kit
•
Faulty brake caliper seal
•
Loose union bolt
•
Damaged brake hose
•
Oil or grease on the brake disc
•
Oil or grease on the brake pad
•
Incorrect brake fluid level
EAM30361
FRONT FORK OIL LEAKING
Chassis
1. Front fork
•
Bent, damaged, or rusty inner tube
•
Cracked or damaged outer tube
•
Improperly installed oil seal
•
Damaged oil seal lip
•
Incorrect oil level (high)
•
Loose damper rod assembly bolt
•
Damaged damper rod assembly bolt copper
washer
•
Cracked or damaged cap bolt O-ring
EAM30321
FAULTY FRONT FORK LEGS
Chassis
1. Front fork
•
Bent or damaged inner tube
•
Bent or damaged outer tube
•
Broken fork spring
•
Bent or damaged damper rod
•
Incorrect oil viscosity
•
Incorrect oil level
EAM30322
UNSTABLE HANDLING
Chassis
1. Handlebar
•
Bent or improperly installed handlebar
2. Steering head components
•
Improperly installed upper bracket
•
Improperly installed lower bracket
(improperly tightened ring nut)
•
Bent steering stem
•
Damaged ball bearing or bearing race
3. Front fork leg(s)
•
Uneven oil levels (both front fork legs)
•
Unevenly tensioned fork spring (both front
fork legs)
•
Broken fork spring
•
Bent or damaged inner tube
•
Bent or damaged outer tube
4. Swingarm
•
Worn bearing or bushing
•
Bent or damaged swingarm
5. Rear shock absorber assembly (-ies)
•
Faulty rear shock absorber spring
•
Leaking oil or gas
6. Tire(s)
•
Uneven tire pressures (front and rear)
•
Incorrect tire pressure
•
Uneven tire wear
7. Wheel(s)
•
Incorrect wheel balance
•
Broken or loose spoke
•
Damaged wheel bearing
•
Bent or loose wheel axle
•
Excessive wheel runout
8. Frame
•
Bent frame
•
Damaged steering head pipe
•
Improperly installed bearing race
Summary of Contents for YZ 2019 Series
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 40: ...MOTORCYCLE CARE AND STORAGE 1 28...
Page 63: ...LUBRICATION POINTS AND LUBRICANT TYPES 2 22...
Page 66: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25...
Page 68: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27...
Page 70: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 29...
Page 72: ...CABLE ROUTING DIAGRAM 2 31 EAM20152 CABLE ROUTING DIAGRAM...
Page 74: ...CABLE ROUTING DIAGRAM 2 33...
Page 76: ...CABLE ROUTING DIAGRAM 2 35...
Page 78: ...CABLE ROUTING DIAGRAM 2 37...
Page 80: ...CABLE ROUTING DIAGRAM 2 39...
Page 82: ...CABLE ROUTING DIAGRAM 2 41...
Page 84: ...CABLE ROUTING DIAGRAM 2 43...
Page 86: ...CABLE ROUTING DIAGRAM 2 45...
Page 126: ...ELECTRICAL SYSTEM 3 38...
Page 177: ...FRONT FORK 4 49 1...
Page 196: ...CHAIN DRIVE 4 68...
Page 217: ...CAMSHAFT 5 18 Spark plug Spark plug 13 N m 1 3 kgf m 9 6 lb ft T R...
Page 237: ...ELECTRIC STARTER 5 38...
Page 256: ...OIL PUMP AND BALANCER GEAR 5 57 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...
Page 262: ...GENERATOR AND STARTER CLUTCH 5 63 1 a 3 3 2 4...
Page 276: ...TRANSMISSION 5 77...
Page 284: ...WATER PUMP 6 7...
Page 290: ...FUEL TANK 7 5 A Left B Right 1 1 A 0 mm 0 in B 1 1 15 mm 0 59 in...
Page 296: ...THROTTLE BODY 7 11...
Page 299: ......
Page 313: ...CHARGING SYSTEM 8 14...
Page 343: ...FUEL INJECTION SYSTEM 8 44...
Page 347: ...FUEL PUMP SYSTEM 8 48...
Page 348: ...ELECTRICAL COMPONENTS 8 49 EAM20147 ELECTRICAL COMPONENTS 9 10 1 3 2 4 5 6 7 8...
Page 350: ...ELECTRICAL COMPONENTS 8 51 11 10 9 2 3 1 6 7 8 4 5...
Page 352: ...ELECTRICAL COMPONENTS 8 53 EAM30289 CHECKING THE SWITCHES 4 1 3 2 B B Sb B B B B B B B B...
Page 368: ...ELECTRICAL COMPONENTS 8 69...
Page 376: ...LIST OF SELF DIAGNOSTIC AND FAIL SAFE ACTIONS 9 7...