Yamaha YZF-R125 Service Manual: Troubleshooting

The ignition system fails to operate (no spark or intermittent spark).

NOTE:

  • Before troubleshooting, remove the following part(s):

1. Seats

2. Fuel tank

3. Right side cover

4. Left side panel

5. Left upper side cowling

Troubleshooting


Troubleshooting


    Circuit diagram
    2. Crankshaft position sensor 4. Main fuse 5. Main switch 8. Sidestand switch 9. Battery 17.Engine stop switch 23.Lean angle sensor 25.ECU (engine control unit) 26.Ignition coil 27.Spark ...

    Electric starting system
    ...

    Other materials:

    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 ...

    Checking the starter motor operation
    1. Check: Starter motor operation Does not operate → Perform the electric starting system troubleshooting, starting with step 4. Refer to "TROUBLESHOOTING" on page 8-9. a. Connect the positive battery terminal "1" and starter motor lead "2" with a jumper lead "3". W ...

    Fuel tank cap
    Fuel tank cap Fuel tank cap lock cover Unlock. To remove the fuel tank cap Open the fuel tank cap lock cover. Insert the key into the lock and turn it 1/4 turn counterclockwise. The lock will be released and the fuel tank cap can be removed. To install the fuel tank ca ...

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