Yamaha YZF-R125 Quiz
Electrical system

Checking the crankshaft position sensor

In this manual: Electrical system
General information — 15Specifications — 14Periodic checks and adjustments — 41Chassis — 67Engine — 76Cooling system — 12Fuel system — 10Electrical system — 61Troubleshooting — 13
~1min read

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.

Test yourself

A quick Yamaha YZF-R125 quiz: every answer comes with an explanation and a link to the manual page.