Yamaha YZF-R125 Service Manual: Checking the drive sprocket

Yamaha YZF-R125 Service Manual / Chassis / Chain drive / Checking the drive sprocket

1. Check:

  • Drive sprocket More than 1/4 tooth "a" wear
    Replace the drive chain sprockets as a set.

    Bent teeth Replace the drive
    chain sprockets as a set.

Checking the drive sprocket


b. Correct

1. Drive chain roller

2. Drive chain sprocket

Checking the rear wheel sprocket

Refer to "CHECKING AND REPLACING THE REAR WHEEL SPROCKET" on page 4-15.

Checking the rear wheel drive hub

Refer to "CHECKING THE REAR WHEEL DRIVE HUB" on page 4-15.

    Checking the drive chain
    1. Measure: 15-link section "a" of the drive chain Out of specification Replace the drive chain. a. Measure the length "a" between the inner sides of the pins and the length "b" between t ...

    Installing the drive chain
    1. Lubricate: Drive chain Master link 2. Install: Drive sprocket Drive sprocket retainer bolts 3. Install: Master link O-rings Master link plate Master link clip "1" ...

    Other materials:

    Checking the brake fluid level
    1. Stand the vehicle on a level surface. NOTE: Place the vehicle on a suitable stand. Make sure the vehicle is upright. 2. Check: Brake fluid level Below the minimum level mark "a" → Add the recommended brake fluid to the proper level. A. Front brake B. Rear brake WA ...

    Cable routing
    Front brake light switch lead Right handlebar switch lead Throttle cable Main switch Clutch cable Clutch switch lead Left handlebar switch lead Sub-wire harness Horn Speed sensor lead Front brake hose Main switch lead Left headlight assembly lead Right headlight asse ...

    Checking the fuel sender
    1. Drain the fuel from the fuel tank. 2. Check: Fuel sender resistance Out of specification → Replace the fuel sender. a. Connect the pocket tester ( × 10) to the fuel sender coupler as shown. Positive tester probe sky blue "1" Negative tester probe orange/white " ...

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