Yamaha YZ125 2022 Owner's Service Manual page 243

2 2
3. Replace:
• Throttle position sensor
4. Install:
• Throttle position sensor "1"
• Throttle position sensor screw "2"
TIP
• Align the slot "a" in the throttle position sensor
with the projection "b" on the carburetor while
the lever "c" is held down.
• Temporarily tighten the throttle position sensor
screw.
c
1
2 2 2
5. Install:
• Mixing chamber top
• Carburetor
Refer to "CARBURETOR" on page 7-3.
6. Adjust:
• Standard adjustment of engine idling speed
for throttle position sensor
a. Set the digital tachometer to the high ten-
sion cord.
b. Turn the throttle stop screw "1" until the
specified idle speed.
Refer to "CHECKING THE ENGINE
IDLING SPEED" on page 3-5.
Standard adjustment of engine
idling speed
1700–1900 r/min
1 1 1
a b
8-12
ELECTRICAL COMPONENTS
7. Insert the thin electric conductors "2" (lead
wire) into the throttle position sensor coupler
"1", as shown, and connect the tester to them.
• Positive tester probe 
Yellow "3"
• Negative tester probe 
Black "4"
3
4
8. Start the engine.
9. Adjust:
• Throttle position sensor output voltage
a. Adjust the installation angle of the throttle
position sensor "1" to obtain the specified
output voltage.
Throttle position sensor output
voltage
0.5–0.7 V
1
10.Put the aligning marks "a" on the throttle po-
sition sensor and carburetor.
1
2
2
1 1 1