Yamaha YZF-R125 Service Manual: Checking the crankshaft position sensor

Yamaha YZF-R125 Service Manual / Electrical system / Electrical components / Checking the crankshaft position sensor

1. Disconnect:

  • Crankshaft position sensor coupler (from the wire harness)

2. Check:

Crankshaft position sensor resistance Out of specification  Replace
the crankshaft position sensor/stator assembly.


a. Connect the pocket tester ( × 100) to the crankshaft position sensor coupler as shown.


  • Positive tester probe
    red "1"
  • Negative tester probe
    white "2"

b. Measure the crankshaft position sensor resistance.

    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 ...

    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 ...

    Other materials:

    Removing the primary drive gear and balancer gears
    1. Loosen: Primary drive gear nut "1" NOTE: Place the aluminum plate "a" between the balancer drive gear "2" and the balancer driven gear "3", and then loosen the primary drive gear nut. 2. Straighten the lock washer tab. 3. Loosen: Balancer driven gear nut "1" NOTE: Place ...

    Adjusting the valve clearance
    The following procedure applies to all of the valves. NOTE: Valve clearance adjustment should be made on a cold engine, at room temperature. When the valve clearance is to be measured or adjusted, the piston must be at top dead center (TDC) on the compression stroke. 1. Remove: ...

    Checking the steering
    Worn or loose steering bearings may cause danger. Therefore, the operation of the steering must be checked as follows at the intervals specified in the periodic maintenance and lubrication chart. Place a stand under the engine to raise the front wheel off the ground. WARNING! To ...

    2025 Copyright www.yam-r125.net |