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 radiator fan motor
1. Check:
Radiator fan motor
Faulty/rough movement → Replace.
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
Positive tester probe →
blue "1"
Negative tester probe →
black "2"
c. Measure ...
Checking the connections
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
Lead
Coupler
Connector
2. Check:
Lead
Coupler
Connector
Moisture → Dry with an air blower.
Rust/stains → Connect and disconnect several
times.
3. Check:
All co ...
Removing the cylinder head
1. Align:
"I" mark "a" on the generator rotor
(with the stationary pointer "b" on the generator
cover)
a. Turn the crankshaft counterclockwise.
b. When the piston is at TDC on the compression
stroke, align the "I" mark "c" on the camshaft
sprocket with the mark "d" on the
cylinder h ...