Yamaha YZF-R125 Service Manual: 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. Connect the pocket tester ( 
×
1) to the stator
coil coupler as shown.
b. Measure the stator coil resistance.
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. Con ...
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester ...
Other materials:
Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that
the fuel injection system is
operating normally. If this function detects a malfunction in the system, it
immediately operates the engine
under substitute characteristics and illuminates the engine trouble warning
li ...
Self-diagnostic function table
If the ECU detects an abnormal signal from a sensor while the vehicle is
being driven, the ECU illuminates
the engine trouble warning light and provides the engine with alternate
operating instructions that
are appropriate for the type of malfunction.
When an abnormal signal is received fro ...
Troubleshooting method
The engine operation is not normal and the
engine trouble warning light comes on.
1. Check:
Fault code number
a. Check the fault code number displayed on
the FI diagnostic tool.
b. Identify the faulty system with the fault code.
Refer to "Self-Diagnostic Function table".
c. Identi ...