Yamaha YZF-R125 Service Manual: 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. Elevate the front wheel and slowly rotate it.
d. Measure the voltage of gray and gray/black.
With each full rotation of the front wheel, the voltage reading should cycle from 0 V to 5.0 V to 0 V to 5.0 V.
Checking the fuel sender
1. Drain the fuel from the fuel tank.
2. Check:
Fuel sender resistance
Out of specification → Replace the fuel
sender.
a. Connect the pocket tester ( ×
10) to the fuel
sender c ...
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.
Posi ...
Other materials:
Replacing an auxiliary light bulb
This model is equipped with two auxiliary
lights. If an auxiliary light bulb burns
out, replace it as follows.
Remove the socket (together with
the bulb) by pulling it out.
Auxiliary light bulb
Remove the burnt out bulb by pulling
it out.
Insert a new bulb into t ...
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 ...
Main switch/steering lock
Main switch/steering lock
The main switch/steering lock controls
the ignition and lighting systems, and is
used to lock the steering. The various
positions are described below.
ON
All electrical circuits are supplied with
power, the meter lighting, taillight, license
plate light and ...