Yamaha YZF-R125 Service Manual: Throttle position sensor
1. Check:
- Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
- Positive tester probe → gray/red terminal "1"
- Negative tester probe → gray/black terminal "2"
b. Measure the throttle position sensor input voltage.
Out of specification → Replace or repair the
wire harness.
c. Connect the digital circuit tester to the terminals of the throttle body sensor assembly coupler as shown.
- Positive tester probe → yellow terminal "3"
- Negative tester probe → gray/black terminal "2"
d. While slowly opening the throttle, check that the throttle position sensor output voltage is increased.
Voltage does not change or it changes abruptly → Replace the throttle body.
Out of specification (closed position) →
Replace
the throttle body.
Checking the throttle body sensor assembly
WARNING
Do not remove the throttle body sensor assembly.
Handle the throttle body sensor assembly
with special care
Never subject the throttle body sensor assembly
to strong ...
Intake air pressure sensor
1. Check:
Intake air pressure sensor output voltage
Out of specification Replace the throttle
body.
a. Connect the pocket tester (DC 20 V) to the
throttle body sensor assembly coupler as
...
Other materials:
Changing the engine oil
1. Remove:
Right bottom cowling
Right upper side cowling
Right lower side cowling
Refer to "GENERAL CHASSIS" on page 4-1.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Place a container under the engine oil drain
bolt.
4. Install:
Engine oil d ...
Installing the shift forks and shift drum assembly
1. Install:
Shift fork-L "1"
Shift fork-C "2"
Shift fork-R "3"
Shift drum assembly "4"
Springs
Shift fork guide bar "5"
NOTE:
The embossed marks on the shift forks should
face towards the right side of the engine and be
in the following sequence: "R", "C", "L".
2. Check:
Tr ...
Installing the rear wheel (disc)
1. Install:
Rear brake disc
NOTE:
Tighten the brake disc bolts in stages and in a
crisscross pattern.
2. Check:
Rear brake disc
Refer to "CHECKING THE REAR BRAKE
DISC" on page 4-33.
3. Lubricate:
Rear wheel axle
Contact surface of rear wheel hub and rear
wheel
Whee ...