Yamaha YZF-R125 Service Manual: Troubleshooting
If the fuel pump fails to operate.
NOTE:
- Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
Circuit diagram
4. Main fuse
5. Main switch
9. Battery
17.Engine stop switch
25.ECU (engine control unit)
30.Fuel pump
64.Ignition fuse ...
Electrical components
1. Main switch
2. Clutch switch
3. Front brake light switch
4. Ignition coil
5. Throttle body sensor assembly (intake air
pressure sensor, intake air temperature
sensor, throttle position se ...
Other materials:
Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
Positive tester probe
gray "1"
Negative tester probe
gray/black "2"
b. Set the main switch to "ON".
c. ...
Specifications
Dimensions:
Overall length:
2015 mm (79.3 in)
Overall width:
660 mm (26.0 in)
Overall height:
1065 mm (41.9 in)
Seat height:
818 mm (32.2 in)
Wheelbase:
1355 mm (53.3 in)
Ground clearance:
155 mm (6.10 in)
Minimum turning radius:
3100 mm (122.0 in)
Weight:
With oil and fuel:
138.0 k ...
Incorrect engine idling speed
Engine
1. Cylinder and cylinder head
Incorrect valve clearance
Damaged valve train components
2. Air filter
Clogged air filter element
Fuel system
1. Throttle body
Damaged or loose throttle body joint
Improperly adjusted engine idling speed (idle
adjusting screw)
Improper ...