2004 YAMAHA WR 450F oil

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 posi-
tion.
Out of specification → Replace.
Tester (+) lead → Yellow lead 1
Tester (–) lead → Black lead 2
TPS coil variable
resistanceTester selec-
tor position
Full closedFull opened
kΩ × 1 0 ~ 2 kΩ at
20 ˚C
(68 ˚F)4 ~ 6 kΩ 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 sys-
tem proper for connections.Repair or replace.
Check the rectifier/regulator.Out-put
voltageReplace.
Pocket tester:
YU-3112-C/90890-03112
OK
OK
OK
No good
Improperly connected
No 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

7 - 12
TUNSETTING
EC722011
Front fork setting
The front fork setting should be made depend-
ing on the rider’s feeling of an actual run and
the circuit conditions.
The front fork setting includes the following
three factors:
1. Setting of air spring characteristics
Change the fork oil level.
2. Setting of spring preload
Change the spring.
Install the adjustment washer.
3. Setting of damping force
Change the compression damping.
Change the rebound damping.
The spring acts on the load and the
damping force acts on the cushion
travel speed.
EC723001
Change in level and characteristics of fork
oil
Damping characteristic near the final stroke can
be changed by changing the fork oil amount.
CAUTION:
Adjust the oil level in 5 mm (0.2 in) incre-
ments or decrements. Too low oil level
causes the front fork to produce a noise at
full rebound or the rider to feel some pres-
sure on his hands or body. Alternatively,
too high oil level will develop unexpectedly
early oil lock with the consequent shorter
front fork travel and deteriorated perfor-
mance an characteristics. Therefore, adjust
the front fork within the specified range.
* For EUROPE, AUS, NZ and ZA
ÅAir spring characteristics in relation to oil level
change
ıLoad
ÇStroke
1Max. oil level
2Standard oil level
3Min. oil level
Standard oil level:
125 mm (4.92 in)
* 130 mm (5.12 in)
Extent of adjustment:
80 ~ 150 mm (3.15 ~ 5.91 in)
From top of outer tube with
inner tube and damper rod fully
compressed without spring.
Å

7 - 20
TUNSETTING
EC72H002
Suspension setting
Front fork
NOTE:
If any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
Before any change, set the rear shock absorber sunken length to the standard figure 90 ~
100 mm (3.5 ~ 3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff over entire range

Compression damping
Oil level (oil amount)
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with soft spring.
Unsmooth movement
over entire range

Outer tube
Inner tube
Under bracket tightening
torqueCheck for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Retighten to specified torque.
Poor initial
movement

Rebound damping
Oil sealTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Apply grease in oil seal wall.
Soft over entire range,
bottoming out

Compression damping
Oil level (oil amount)
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with stiff spring.
Stiff toward stroke end
Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end,
bottoming out
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial movement
Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture

Compression damping
Rebound damping
Balance with rear end
Oil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tend-
ing to upper front pos-
ture

Compression damping
Balance with rear end
Spring
Oil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when
one passenger is astride seat (upper rear posture).
Replace with soft spring.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).