Yamaha 2011 WR250FA Owner's Service Manual page 306

HANDLING NOTE
Do not loosen the screw (throttle position
sensor) "1" except when changing the
throttle position sensor due to failure be-
cause it will cause a drop in engine perfor-
mance.
CHECKING THE COUPLERS AND LEADS
CONNECTION
1. Check:
• Couplers and leads connection
Rust/dust/looseness/short-circuit → Repair
or replace.
CHECKING THE THROTTLE POSITION
SENSOR COIL
1. Inspect:
• Throttle position sensor coil resistance
Out of specification → Replace.
Tester (+) lead → Blue lead "1"
Tester (-) lead → Black lead "2"
Throttle position
sensor coil resis-
tance
4–6 kΩ at 20°C
(68 °F)
THROTTLE POSITION SENSOR SYSTEM
Tester selector
position
kΩ×1
7-18
2. Loosen:
• Throttle stop screw "1"
Turn out the throttle stop screw until the throttle
shaft is in the full close position.
3. Inspect:
• Throttle position sensor coil variable resis-
tance
Check that the resistance in increased as
the throttle grip is moved from the full close
position to the full open position.
Out of specification → Replace.
Tester (+) lead → Yellow lead "1"
Tester (-) lead → Black lead "2"
Throttle position sen-
sor coil variable resis-
tance
Full closed
opened
Zero –3 4–6 kΩat
kΩat 20°C 20 °C (68
(68 °F)
Tester se-
lector posi-
tion
Full
kΩ×1
°F)