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:

    Adjusting the clutch lever free play
    Adjusting the clutch lever free play Clutch lever free play adjusting bolt Clutch lever free play The clutch lever free play should measure 10.0-15.0 mm (0.39-0.59 in) as shown. Periodically check the clutch lever free play and, if necessary, adjust it as follows. Slide the ...

    Adjusting the throttle cable free play
    NOTE: Prior to adjusting the throttle cable free play, the engine idling speed should be adjusted. 1. Check: Throttle cable free play "a" Out of specification →Adjust. 2. Remove: Right side panel Refer to "GENERAL CHASSIS" on page 4-1. 3. Adjust: Throttle cable f ...

    Checking the cooling system
    1. Remove: Side covers Upper side cowlings Refer to "GENERAL CHASSIS" on page 4-1. 2. Check: Radiator "1" Radiator inlet hose "2" Radiator outlet hose "3" Coolant reservoir hose "4" Water pump breather hose "5" Cracks/damage → Replace. Refer to "RADIATOR" on page 6-1 ...

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