Yamaha YZF-R125 Service Manual: Electrical system
- Ignition system
- Electric starting system
- Charging system
- Lighting system
- Signaling system
- Cooling system
- Fuel injection system
- Circuit diagram
- Ecu self-diagnostic function
- Self-diagnostic function table
- Troubleshooting method
- Diagnostic mode
- Troubleshooting details
- Fuel pump system
- Electrical components
- Checking the switches
- Checking the bulbs and bulb sockets
- Checking the fuses
- Checking and charging the battery
- Checking the relays
- Checking the turn signal relay
- Checking the diode
- Checking the spark plug cap
- Checking the ignition coil
- Checking the ignition spark gap
- Checking the crankshaft position sensor
- Checking the lean angle sensor
- Checking the starter motor operation
- Checking the stator coil
- Checking the rectifier/regulator
- Checking the horn
- Checking the fuel sender
- Checking the speed sensor
- Checking the radiator fan motor
- Checking the coolant temperature sensor
- Checking the throttle body sensor assembly
- Checking the fid (fast idle solenoid)
Air induction system
1. Air induction system hose (air filter case to
reed valve assembly)
2. Air induction system reed valve assembly
3. Air induction system hose (reed valve
assembly to exhaust pipe)
Checki ...
Ignition system
...
Other materials:
Checking the timing chain tensioner
1. Check:
Timing chain tensioner
Cracks/damage/rough movement Replace.
a. Lightly press the timing chain tensioner rod
into the timing chain tensioner housing by
hand.
NOTE:
While pressing the timing chain tensioner rod,
wind it clockwise with a thin screwdriver "1" until
it stops.
b. ...
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 ...
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 ...