Yamaha YZF-R125 Owners Manual: Drive chain slack

The drive chain slack should be checked before each ride and adjusted if necessary.

To check the drive chain slack

  1. Place the motorcycle on the sidestand.

TIP
When checking and adjusting the drive chain slack, there should be no weight on the motorcycle.

  1. Shift the transmission into the neutral position.
  2. Move the rear wheel by pushing the motorcycle to locate the tightest portion of the drive chain, and then measure the drive chain slack as shown.
Drive chain slack:

30.0-40.0 mm (1.18-1.57 in)


  1. Drive chain slack

  1. If the drive chain slack is incorrect, adjust it as follows.

To adjust the drive chain slack

  1. Loosen the axle nut and the locknut on each side of the swingarm.


  1. Axle nut

  2. Drive chain slack adjusting bolt

  3. Locknut

  4. Alignment marks

  1. To tighten the drive chain, turn the drive chain slack adjusting bolt on each side of the swingarm in direction (a). To loosen the drive chain, turn the adjusting bolt on each side of the swingarm in direction (b), and then push the rear wheel forward. NOTICE: Improper drive chain slack will overload the engine as well as other vital parts of the motorcycle and can lead to chain slippage or breakage. To prevent this from occurring, keep the drive chain slack within the specified limits.

TIP
Using the alignment marks on each side of the swingarm, make sure that both drive chain pullers are in the same position for proper wheel alignment.

  1. Tighten the axle nut, then the locknuts to their specified torques.
Tightening torques:

Axle nut:

85 Nm (8.5 m.kgf, 61 ft.lbf)

Locknut:

16 Nm (1.6 m.kgf, 11 ft.lbf)
    Changing the brake fluid
    Have a Yamaha dealer change the brake fluid at the intervals specified in the periodic maintenance and lubrication chart. In addition, have the brake hose replaced every four years or whenev ...

    Cleaning and lubricating the drive chain
    The drive chain must be cleaned and lubricated at the intervals specified in the periodic maintenance and lubrication chart, otherwise it will quickly wear out, especially when riding in dusty ...

    Other materials:

    Measuring the compression pressure
    NOTE: Insufficient compression pressure will result in a loss of performance. 1. Measure: Valve clearance Out of specification →Adjust. Refer to "ADJUSTING THE VALVE CLEARANCE" on page 3-3. 2. Start the engine, warm it up for several minutes, and then turn it off. 3. Remove: ...

    Adjusting the clutch cable free play
    1. Check: Clutch cable free play "a" Out of specification Adjust. 2. Adjust: Clutch cable free play a. Pull back the rubber cover "1" b. Loosen the locknut "2". c. Turn the adjusting bolt "3" in direction "a" or "b" until the specified clutch cable free play is obtained. ...

    Replacing the fuses
    Replacing the fuses Fuse box Spare fuse Headlight fuse Signaling system fuse Ignition fuse Radiator fan fuse Main fuse The fuse box is located under the rider seat. If a fuse is blown, replace it as follows. Turn the key to "OFF" and turn off the electrical circuit i ...

    2025 Copyright www.yam-r125.net |