Yamaha YZ450FA 2011, Owner'S Service Manual

Page: 271 / 318

7-9
THROTTLE POSITION SENSOR SYSTEM
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
1. Inspect:
• Throttle position sensor resistance
Out of specification
→
Replace.
2. Inspect:
• Throttle position sensor variable resistance
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.
CHANGING AND ADJUSTING THE
THROTTLE POSITION SENSOR
1. Remove:
• Throttle position sensor coupler
2. Remove:
• Screw (throttle position sensor) "1"
• Throttle position sensor "2"
Loosen the screw (throttle position sensor) us-
ing the T25 bit.
Tester (+) lead
→
Blue lead "1"
Tester (-) lead
→
Black lead "2"
Throttle position
sensor coil resis-
tance
Tester selector
position
4–6 k
Ω
at 20°C
(68 °F)
k
Ω
×1
Y
B
L
Tester (+) lead
→
Yellow lead "1"
Tester (-) lead
→
Black lead "2"
Throttle position sen-
sor coil variable resis-
tance
Tester se-
lector posi-
tion
Full closed
Full
opened
k
Ω
×1
Zero –2
k
Ω
at 20°C
(68 °F)
4–6 k
Ω
at
20 °C (68
°F)
Y
B
L