Yamaha YZ450FA Automobile User Manual


 
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 kΩ at 20°C
(68 °F)
kΩ×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
kΩ×1
Zero –2
kΩat 20°C
(68 °F)
4–6 kΩat
20 °C (68
°F)
Y
B
L