Yamaha YZF-R125 Service Manual: 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"

Checking the horn


c. Measure the horn resistance.

2. Check:

Horn sound Faulty sound Adjust or replace.


a. Connect a battery (12 V) to the horn.

b. Turn the adjusting screw in direction "a" or "b" until the specified horn sound is obtained.

Checking the horn


    Checking the rectifier/regulator
    1. Check: Rectifier/regulator output voltage Out of specification → Replace the rectifier/ regulator. a. Set the engine tachometer to the spark plug lead. b. Connect the pocket tester ...

    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 c ...

    Other materials:

    Checking the clutch boss
    1. Check: Clutch boss splines Damage/pitting/wear Replace the clutch boss. NOTE: Pitting on the clutch boss splines will cause erratic clutch operation. Checking the pressure plate 1. Check: Pressure plate Cracks/damage Replace. Checking the clutch push lever and short clutch push ...

    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. ...

    Adjusting the brake pedal free play
    Adjusting the brake pedal free play Brake pedal free play The brake pedal free play should measure 3.5-4.5 mm (0.14-0.18 in) as shown. Periodically check the brake pedal free play and, if necessary, have a Yamaha dealer adjust it. WARNING An incorrect brake pedal free play in ...

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