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 valve seats
    The following procedure applies to all of the valves and valve seats. 1. Eliminate: Carbon deposits (from the valve face and valve seat) 2. Check: Valve seat Pitting/wear Replace the cylinder head. 3. Measure: Valve seat width C "a" Out of specification Replace the ...

    Adjusting the drive chain slack
    NOTE: The drive chain slack must be checked at the tightest point on the chain. CAUTION:A drive chain that is too tight will overload the engine and other vital parts, and one that is too loose can skip and damage the swingarm or cause an accident. Therefore, keep the drive ...

    Intake air temperature sensor
    1. Check: Intake air temperature sensor resistance Out of specification Replace the throttle body. a. Connect the pocket tester ( × 1k) to the throttle body sensor assembly coupler as shown. Positive tester probe brown/white "1" Negative tester probe gray/black ...

    2025 Copyright www.yam-r125.net |