Yamaha YZF-R125 Service Manual: Troubleshooting details
This section describes the measures per fault code number displayed on the FI diagnostic tool. Check and service the items or components that are the probable cause of the malfunction following the order given.
After the check and service of the malfunctioning part have been completed, reset the FI diagnostic tool display according to the reinstatement method.
Fault code No.: Fault code number displayed on the FI diagnostic tool when the engine failed to work normally. Refer to "Diagnostic code table".
Diagnostic code No.: Diagnostic code number to be used when the diagnostic mode is operated. Refer to "Sensor operation table" and "Actuator operation table".
Setting the diagnostic mode
1. Set the main switch to "OFF" and the engine stop switch to "
".
2. Disconnect the self-diagnosis signal connector "1", and then connect the FI
diagnostic tool "2" as
shown.
3. Disconnect ...
Fuel pump system
...
Other materials:
Setting the normal mode
NOTE:
The engine speed, coolant temperature, and fault code, if detected, can be
displayed on the LCD of the
FI diagnostic tool when the tool is connected to the vehicle and is set to the
normal mode.
1. Set the main switch to "OFF" and the engine stop switch to "".
2. Disconnect the self- ...
Checking the valves and valve guides
The following procedure applies to all of the
valves and valve guides.
1. Measure:
Valve-stem-to-valve-guide clearance
Out of specification Replace the
valve
guide.
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter "a" -
Valve stem diameter "b"
2. Replace:
...
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 (DC 20 V) to the
rectifier/regulator coupler as shown.
Positive tester probe
red "1"
Negat ...