2006 YAMAHA WR 450F coil

6 - 20
–+ELECTPS (THROTTLE POSITION SENSOR) SYSTEM
HANDLING NOTE
CAUTION:
Do not loosen the screws {TPS (throttle
position sensor)}
1 except when changing
the TPS (throttle position sensor) due to
failure because it will cause a drop in
engine performance.
1
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
•Couplers and leads connection
Rust/dust/looseness/short-circuit →
Repair or replace.
TPS COIL INSPECTION
1. Inspect:
•TPS coil resistance
Out of specification → Replace.
2. Loosen:
•Throttle stop screw 1
NOTE:
Turn out the throttle stop screw until the throt-
tle shaft is in the full close position.Tester (+) lead
→ Blue lead
1
Tester (–) lead
→ Black lead
2
TPS coil
resistanceTester selector
position
4 ~ 6 kΩ at
20 °C (68 °F)kΩ × 1

6 - 21
–+ELECTPS (THROTTLE POSITION SENSOR) SYSTEM
3. Inspect:
•TPS coil 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.
Tester (+) lead
→ Yellow lead
1
Tester (–) lead
→ Black lead
2
TPS coil variable
resistanceTester selec-
tor position
Full closed Full opened
k
Ω
× 1 0 ~ 2 k
Ω
at 20 °C
(68°F)4 ~ 6 k
Ω
at 20 °C
(68°F)
TPS REPLACEMENT AND ADJUSTMENT
1. Remove:
•TPS coupler
•Screw (TPS) 1
•TPS 2
NOTE:
Loosen the screws (TPS) using the T25 bit.
2. Replace:
•TPS
3. Install:
•TPS 1
•Screw (TPS) 2
•TPS coupler
NOTE:
•Align the slot a in the TPS with the projec-
tion b on the carburetor.
•Temporarily tighten the screws (TPS).
12
21
b
a

–+ELEC
6 - 24
LIGHTING SYSTEM
LIGHTING SYSTEM
INSPECTION STEPS
Refer to the following flow chart when inspecting the ignition system for possible problems.
NOTE:
•Replace the bulb and/or bulb socket.
1) Seat
2) Fuel tank
•Use the following special tool.
Check the bulb and bulb
socket.Replace the bulb and/
or bulb socket.
Check the AC magneto. Lighting coil Replace.
Check the entire lighting
system proper for connec-
tions.Repair or replace.
Check the rectifier/regulator.Out-put
voltageReplace.
Pocket tester:
YU-3112-C/90890-03112
OK
OK
OK
No good
Improperly connectedNo good
No good

6 - 25
–+ELECLIGHTING SYSTEM
AC MAGNETO INSPECTION
1. Inspect:
•Lighting coil resistance
Out of specification → Replace.
RECTIFIER/REGULATOR INSPECTION
1. Connect the battery leads.
2. Start the engine.
3. Turn on the headlight and taillight by turn-
ing on the lights switch.
4. Inspect:
•Out-put voltage
Out of specification → Replace rectifier/
regulator. Tester (+) lead
→ Yellow lead
1
Tester (–) lead
→ Ground
2
Lighting coil
resistanceTester selector
position
0.224 ~ 0.336
Ω
at 20 °C (68 °F)Ω
× 1
Tester (+) lead
→ Yellow lead
1
Tester (–) lead
→ Black lead
2
Out-put voltageTester selector
position
13.0 ~ 14.0 V at
5,000 r/minACV-20
R
BW
Y1
2