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:
Removing the piston
1. Remove:
Piston pin clips "1"
Piston pin "2"
Piston "3"
CAUTION:Do not use a hammer to drive the piston
pin
out.
NOTE:
Before removing the piston pin clip, cover the
crankcase opening with a clean rag to prevent
the piston pin clip from falling in ...
Fi system
The fuel pump delivers fuel to the fuel injector via the fuel filter. The
pressure regulator maintains the
fuel pressure that is applied to the fuel injector at only 250 kPa (2.50 kg/cm²,
36.3 psi). Accordingly,
when the energizing signal from the ECU energizes the fuel injector, the fuel ...
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur during
operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
repre ...