Yamaha YZF R125 clutch problems

Yamaha YZF R125 for sale on Ebay UK

Yamaha YZF R125 parts for sale on Ebay UK

   

Yamaha YZF R125 Workshop Manuals on Ebay UK 

⚠️ SAFETY FIRST: Always wear appropriate PPE and ensure the bike is secure before starting any engine work.

Troubleshoot and repair your Yamaha YZF-R125 clutch with this comprehensive rebuild guide. This post covers common symptoms like slipping and dragging, with a step-by-step inspection of plates and springs.

Critical Service Limits:

• Clutch Spring Free Length: Replace if below 43.5mm.

• Friction Plate Thickness: Standard is ~3.0mm; replace if below 2.8mm.

• Clutch Plate Warpage: Maximum limit is 0.20mm.

Learn how to measure for warpage using a feeler gauge and why soaking new friction plates in engine oil for 2–4 hours is essential for a long-lasting repair.

Yamaha YZF R125 clutch common problems rebuild strip inspection test and measure

Clutch slipping     , could be worn plates  , or incorrect adjustment or fitting of components and cables , weak clutch springs ,

Clutch is dragging , engine idle speed too high , broken springs , clutch drum basket damage ,
plates warped or damaged , incorrect spring torque or cable adjustment .



Testing the clutch plates 

First lay the plates on a perfectly flat surface hear i use a tile , i would normally use
an engineers table .

you are going to probe around the outside diameter with your feeler gauge (0.20)  ,
if the feeler gauge is able to go beneath the plate its warped to badly to reuse

Need clutch parts try here on Ebay UK 

You need to measure the clutch spring length to ensure they are in the correct range to out of range them replace as they will not do the job expected of them .

also measure for wear on the friction plates replace any out of

tolerances do not cheat make sure you replace as loss of clutch 

is not a great idea on a ling bike ride .

Here i am testing for warping of any of the clutch plates 

check the edges of plates and basket too 

Another place that can develop judder or knocking on these clutches is the rivets on the drive gear , they become lose and can cause judder or knocking.

Beware of this ball bearing for the clutch actuator pin 

How the clutch works on a YZF R125

Torque Specifications

• Clutch Spring Bolts: 10 Nm (1.0 m·kg, 7.2 ft·lb)

  • Tip: Tighten these in a star pattern to ensure even pressure on the plate.

• Clutch Boss Nut: 70 Nm (7.0 m·kg, 50 ft·lb)

  • Note: This requires a new lock washer; be sure to stake the nut after tightening.

• Clutch Cover Bolts: 10 Nm (1.0 m·kg, 7.2 ft·lb)

  • Tip: These are small M6 bolts; do not over-tighten as they can easily snap or strip the aluminum casing.

Technical Data & Torque Settings:

• Clutch Spring Bolts: 10 Nm / 7.2 ft·lb (Use a criss-cross pattern)

• Clutch Boss Nut: 70 Nm / 50 ft·lb (Always use a new lock washer)

• Clutch Cover Bolts: 10 Nm / 7.2 ft·lb

• Oil Drain Bolt: 20 Nm / 14 ft·lb

 

Pro Tip: Keep track of your clutch cover bolts by punching them into a cardboard template shaped like the engine casing. They are different lengths and must go back into their original holes to avoid damaging the threads.