TROUBLESHOOTING
9-3
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity
• Inferior oil quality
Cooling system
1. Coolant
• Low coolant level
2. Radiator
• Damaged or leaking radiator
• Faulty radiator cap
• Bent or damaged radiator fin
3. Water pump
• Damaged or faulty water pump
• Thermostat
• Thermostat stays closed
• Hose(s) and pipe(s)
• Damaged hose
• Improperly connected hose
• Damaged pipe
• Improperly connected pipe
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
EAS28610
OVERCOOLING
Cooling system
1. Thermostat
• Thermostat stays open
EAS28620
POOR BRAKING PERFORMANCE
• Worn brake pad
• Worn brake disc
• Air in hydraulic brake system
• Leaking brake fluid
• 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
EAS28660
FAULTY FRONT FORK LEGS
Leaking oil
• 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 front fork cap O-ring
Malfunction
• Bent or damaged inner tube
• Bent or damaged outer tube
• Damaged fork spring
• Worn or damaged outer tube bushing
• Bent or damaged damper rod
• Incorrect oil viscosity
• Incorrect oil level
EAS28680
UNSTABLE HANDLING
Handlebars
• Bent or improperly installed right handlebar
• Bent or improperly installed left handlebar
1. Steering head components
• Improperly installed upper bracket
• Improperly installed lower bracket
(improperly tightened ring nut)
• Bent steering stem
• Damaged ball bearing or bearing race
2. 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
3. Swingarm
• Worn bearing
• Bent or damaged swingarm
Rear shock absorber assembly
• Faulty rear shock absorber spring
• Leaking oil
YamahaR125.COM
Summary of Contents for YZF-R125
Page 1: ...5D7 F8197 E0 YAMAHAR125 COM SERVICE MANUAL YZF R125 ...
Page 6: ...YamahaR125 COM ...
Page 8: ...YamahaR125 COM ...
Page 52: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 29 1 2 3 4 YamahaR125 COM ...
Page 70: ...CABLE ROUTING 2 47 YamahaR125 COM ...
Page 73: ...YamahaR125 COM ...
Page 102: ...ELECTRICAL SYSTEM 3 29 YamahaR125 COM ...
Page 105: ...YamahaR125 COM ...
Page 172: ...CHAIN DRIVE 4 67 YamahaR125 COM ...
Page 181: ...ENGINE REMOVAL 5 6 2 2 4 1 3 YamahaR125 COM ...
Page 263: ...THROTTLE BODY 7 8 YamahaR125 COM ...
Page 264: ...AIR INDUCTION SYSTEM 7 9 EAS27040 AIR INDUCTION SYSTEM 1 2 3 YamahaR125 COM ...
Page 268: ...AIR INDUCTION SYSTEM 7 13 YamahaR125 COM ...
Page 271: ...YamahaR125 COM ...
Page 283: ...CHARGING SYSTEM 8 12 1 AC magneto 3 Rectifier regulator 4 Main fuse 9 Battery YamahaR125 COM ...
Page 285: ...CHARGING SYSTEM 8 14 YamahaR125 COM ...
Page 295: ...SIGNALING SYSTEM 8 24 YamahaR125 COM ...
Page 299: ...COOLING SYSTEM 8 28 YamahaR125 COM ...
Page 323: ...FUEL INJECTION SYSTEM 8 52 YamahaR125 COM ...
Page 327: ...FUEL PUMP SYSTEM 8 56 YamahaR125 COM ...
Page 353: ...YamahaR125 COM ...
Page 354: ...YamahaR125 COM ...