Yamaha YZF-R125 Service Manual: 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".

WARNING
  • A wire that is used as a jumper lead must have at least the same capacity of the battery lead, otherwise the jumper lead may burn.
  • This check is likely to produce sparks, therefore, make sure no flammable gas or fluid is in the vicinity.

Checking the starter motor operation


b. Check the starter motor operation.

    Checking the lean angle sensor
    1. Remove: Lean angle sensor 2. Check: Lean angle sensor output voltage Out of specification Replace. a. Connect the lean angle sensor to the wire harness. b. Connect the pocket tester ...

    Checking the stator coil
    1. Disconnect: Stator coil coupler (from the wire harness) 2. Check: Stator coil resistance Out of specification → Replace the crankshaft position sensor/stator assembly. a. Conne ...

    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 ...

    Checking the cylinder and piston
    1. Check: Piston wall Cylinder wall Vertical scratches Replace the cylinder, and replace the piston and piston rings as a set. 2. Measure: Piston-to-cylinder clearance a. Measure cylinder bore "C" with the cylinder bore gauge. NOTE: Measure cylinder bore "C" by takin ...

    Starting circuit cut-off system operation
    If the engine stop switch is set to " " and the main switch is set to "ON" (both switches are closed), the starter motor can only operate if at least one of the following conditions is met: The transmission is in neutral (the neutral switch is closed). The clutch lever is pulled to the ...

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