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:

    Checking the piston pin
    1. Check: Piston pin Blue discoloration/grooves  Replace the piston pin and then check the lubrication system. 2. Measure: Piston pin outside diameter "a" Out of specification Replace the piston pin. 3. Measure: Piston pin bore diameter "b" Out of specifica ...

    Installing the front fork legs
    The following procedure applies to both of the front fork legs. 1. Install: Front fork leg Temporarily tighten the upper and lower bracket pinch bolts. NOTE: Make sure the inner tube end position "a" is 24.5 mm (0.96 in) from the top of the upper bracket. 2. Tighten: Lower br ...

    Installing the shift forks and shift drum assembly
    1. Install: Shift fork-L "1" Shift fork-C "2" Shift fork-R "3" Shift drum assembly "4" Springs Shift fork guide bar "5" NOTE: The embossed marks on the shift forks should face towards the right side of the engine and be in the following sequence: "R", "C", "L". 2. Check: Tr ...

    2026 Copyright www.yam-r125.net |