Yamaha YZF-R125 Service Manual: 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 push rod
  • Broken clutch boss
  • Burnt primary driven gear bushing

2. Engine oil

  • Incorrect oil level
  • Incorrect oil viscosity (high)
  • Deteriorated oil
    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 ...

    Overheating
    Engine 1. Clogged coolant passages Cylinder head and piston Heavy carbon buildup 2. Engine oil Incorrect oil level Incorrect oil viscosity Inferior oil quality Cooling system 1. ...

    Other materials:

    Checking the horn
    1. Check: Horn resistance Out of specification Replace. a. Disconnect the horn connectors from the horn terminals. b. Connect the pocket tester ( × 1) to the horn terminals. Positive tester probe horn terminal "1" Negative tester probe horn terminal "2" c. Measure t ...

    Installing the front fork legs
    The following procedure applies to both of the front fork legs. 1. Install: Front fork leg Temporarily tighten the upper and lower bracket pinch bolts. NOTE: Make sure the inner tube end position "a" is 24.5 mm (0.96 in) from the top of the upper bracket. 2. Tighten: Lower br ...

    Air induction system
    1. Air induction system hose (air filter case to reed valve assembly) 2. Air induction system reed valve assembly 3. Air induction system hose (reed valve assembly to exhaust pipe) Checking the air induction system Air injection The air induction system burns unburned exhaust gases b ...

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