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:
Removing the fuel tank
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Remove:
Fuel hose connector cover "1"
3. Disconnect:
Fuel hose "2"
CAUTION:
Be sure to disconnect the fuel hose by
hand. Do not forcefully disconnect the
hose with tools.
A ...
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 ...
Removing the swingarm
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle
so that there is
no danger of it falling over.
NOTE:
Place the vehicle on a suitable stand so that the
rear wheel is elevated.
2. Measure:
Swingarm side play
Swingarm vertical movement
a. Me ...