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 engine oil level
    1. Stand the vehicle on a level surface. NOTE: Place the vehicle on a suitable stand. Make sure the vehicle is upright. 2. Start the engine, warm it up for several minutes, and then turn it off. 3. Check: Engine oil level The engine oil level should be between the minimum level ...

    Checking the ignition spark gap
    1. Check: Ignition spark gap Out of specification Perform the ignition system troubleshooting, starting with step 5. Refer to "TROUBLESHOOTING" on page 8-3. NOTE: If the ignition spark gap is within specification, the ignition system circuit is operating normally. a. Disconnect the spa ...

    Checking the turn signal relay
    1. Check: Turn signal relay input voltage Out of specification →The wiring circuit from the main switch to the turn signal relay coupler is faulty and must be repaired. a. Connect the pocket tester (DC 20 V) to the turn signal relay terminal as shown. - Positive tester probe  b ...

    2021 Copyright www.yam-r125.net |