Yamaha YZ250F(Z), Owner'S Service Manual

Page: 184 / 196

6-8
THROTTLE POSITION SENSOR SYSTEM
8. Start the engine.
9. Adjust:
• Throttle position sensor output
voltage
Adjustment steps:
a. Adjust the installation angle of the
throttle position sensor "1" to ob-
tain the specified output voltage.
Measure the output voltage accurate-
ly with a digital electronic voltmeter
that gives an easy reading of a small
voltage.
10. Put the aligning marks "a" on the
throttle position sensor and car-
buretor.
11. Stop the engine.
12. Remove the carburetor.
13. Tighten:
• Screw (throttle position sensor)
"1"
Tighten the screw (throttle position
sensor) using the T25 bit.
14. Install the carburetor.
CHECKING THE THROTTLE
POSITION SENSOR INPUT
VOLTAGE
1. Disconnect the throttle position
sensor coupler.
2. Start the engine.
3. Inspect:
• Throttle position sensor input volt-
age
Out of specification
→
Replace the
CDI unit.
Throttle po-
sition sen-
sor output
voltage
Tester se-
lector posi-
tion
0.58–0.78 V DCV
Tester (+) lead
→
Blue lead "1"
Tester (-) lead
→
Black/Blue lead
"2"
Throttle po-
sition sen-
sor input
voltage
Tester se-
lector posi-
tion
4–6 V DCV-20
L Y
B/L