TROUBLESHOOTING
9-2
• Flooded throttle body
• Faulty air induction system
Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Spark plug(s)
• 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(s)
• Broken or shorted primary or secondary coils
• Faulty spark plug lead
• Cracked or broken ignition coil
4. Ignition system
• Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor straight key
EAS30602
POOR MEDIUM-AND-HIGH-SPEED
PERFORMANCE
Refer to “STARTING FAILURE” on page 9-1.
Engine
1. Air filter
• Clogged air filter element
Fuel system
1. Throttle body (-ies)
• Faulty throttle body
2. Fuel pump
• Faulty fuel pump
EAS30603
FAULTY GEAR SHIFTING
Shifting is difficult
Refer to “Clutch drags”.
EAS30604
SHIFT PEDAL DOES NOT MOVE
Shift shaft
• Improperly adjusted shift rod
• Bent shift shaft
Shift drum and shift forks
• Foreign object in a shift drum groove
• Seized shift fork
• Bent shift fork guide bar
Transmission
• Seized transmission gear
• Foreign object between transmission gears
• Improperly assembled transmission
EAS30605
JUMPS OUT OF GEAR
Shift shaft
• Incorrect shift pedal position
• Improperly returned stopper lever
Shift forks
• Worn shift fork
Shift drum
• Incorrect axial play
• Worn shift drum groove
Transmission
• Worn gear dog
EAS30849
FAULTY CLUTCH
Clutch slips
1. Clutch
• Improperly assembled clutch
• Improperly adjusted clutch cable
• Loose or fatigued clutch spring
• Worn friction plate
• Worn clutch plate
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (low)
• Deteriorated oil
Clutch drags
1. Clutch
• Unevenly tensioned clutch springs
• Warped pressure plate
• Bent clutch plate
• Swollen friction plate
• Bent clutch pull rod
• Broken clutch boss
• Burnt primary driven gear bushing
• Match marks not aligned
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (high)
• Deteriorated oil
Summary of Contents for YZF-R25
Page 1: ......
Page 2: ......
Page 3: ......
Page 6: ......
Page 8: ......
Page 25: ...BASIC SERVICE INFORMATION 1 16 ...
Page 32: ...SPECIAL TOOLS 1 23 ...
Page 49: ...TIGHTENING TORQUES 2 16 2 6 8 5 4 1 2 6 3 7 2 10 9 A ...
Page 66: ...COOLING SYSTEM DIAGRAMS 2 33 EAS20020 COOLING SYSTEM DIAGRAMS 1 2 3 1 5 4 4 ...
Page 99: ......
Page 128: ...PERIODIC MAINTENANCE 3 29 ...
Page 146: ...GENERAL CHASSIS 5 4 15 1 b b a a 2 ...
Page 200: ...FRONT FORK 4 69 2 b a 1 ...
Page 209: ...SWINGARM AND REAR SHOCK ABSORBER ASSEMBLY 4 78 2 1 1 1 a A B ...
Page 214: ...CHAIN DRIVE 4 83 ...
Page 256: ...CYLINDER AND PISTONS 5 39 1 ...
Page 310: ...TRANSMISSION 5 93 ...
Page 322: ...WATER PUMP 6 11 ...
Page 336: ...THROTTLE BODIES 7 13 c 1 cylinder d 2 cylinder A Left B Right b a d c A B b 1 ...
Page 337: ...THROTTLE BODIES 7 14 ...
Page 338: ...AIR INDUCTION SYSTEM 7 15 EAS20071 AIR INDUCTION SYSTEM 1 2 3 4 5 1 2 ...
Page 342: ...AIR INDUCTION SYSTEM 7 19 ...
Page 345: ......
Page 355: ...ELECTRIC STARTING SYSTEM 8 10 ...
Page 359: ...CHARGING SYSTEM 8 14 ...
Page 371: ...SIGNALING SYSTEM 8 26 ...
Page 417: ...FUEL PUMP SYSTEM 8 72 ...
Page 420: ...ELECTRICAL COMPONENTS 8 75 2 3 4 5 12 11 10 9 8 7 1 6 ...
Page 440: ...ELECTRICAL COMPONENTS 8 95 ...
Page 451: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 10 ...
Page 453: ......
Page 454: ......