light YAMAHA WR 450F 2003 Service Manual

5 - 22
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
Brake lever 1
Bolt (brake lever) 2
Nut (brake lever) 3
NOTE:
Apply the lithium soap base grease on the
brake lever sliding surface, bolt and contacting
surface of the master cylinder piston.
Rear master cylinder
1. Install:
Copper washer 1
Brake hose 2
Union bolt 3
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as shown and lightly
touches the projection b on the master
cylinder.
T R..6 Nm (0.6 m · kg, 4.3 ft · lb)
T R..6 Nm (0.6 m · kg, 4.3 ft · lb)
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
2. Install:
Master cylinder 1
Bolt (master cylinder) 2
3. Install:
Spring 1
Brake pedal 2
O-ring 3
Bolt (brake pedal) 4
Clip 5
NOTE:
Apply the lithium soap base grease on the
bolt, O-ring and brake pedal bracket.
Install the clip with its stopper portion a fac-
ing inward.
T R..11 Nm (1.1 m · kg, 8.0 ft · lb)
New
T R..26 Nm (2.6 m · kg, 19 ft · lb)

5 - 24
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
Copper washer 1
Brake hose 2
Union bolt 3
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that it contacts
the master cylinder projection a and that
its bent portion b faces downward.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
Rear brake hose
1. Install:
Copper washer 1
Brake hose 2
Union bolt 3
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as shown and lightly
touches the projection b on the caliper.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)

5 - 27
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT FORK REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
Front wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Front caliper Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Headlight
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Brake hose holder 2
3 Pinch bolt (handle crown) 2 Only loosening.
4 Cap bolt 1Loosen when disassembling the front fork.
5 Pinch bolt (under bracket) 2 Only loosening.
6 Front fork 1
1

5 - 40
CHAS
EC5B0000
HANDLEBAR
Extent of removal:1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Headlight
1 Hot starter cable 1 Disconnect at the lever side.
2 Hot starter lever holder 1
3 Clutch cable 1 Disconnect at the lever side.
4 Clutch lever holder 1 Disconnect the clutch switch lead.
5“ENGINE STOP” button 1 Disconnect the “ENGINE STOP” button
lead.
6 Lights switch 1
7 Master cylinder 1 Refer to “REMOVAL POINTS”.
8 Start switch 1 Disconnect the start switch lead.
9 Throttle cable cap 1
10 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
11 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
12 Grip (right) 1 Refer to “REMOVAL POINTS”.
13 Tube guide 1
14 Cover (grip cap) 1
15 Grip (left) 1 Refer to “REMOVAL POINTS”.
16 Handlebar holder (upper) 2
17 Handlebar 1
1
HANDLEBAR

5 - 44
CHASHANDLEBAR
8. Install:
Start switch 1
Master cylinder 2
Master cylinder bracket 3
Bolt (master cylinder bracket) 4
Clamp 5
NOTE:
The start switch and master cylinder bracket
should be installed according to the dimen-
sions shown.
Install the bracket so that the arrow mark a
faces upward.
First tighten the bolt on the upper side of the
master cylinder bracket, and then tighten the
bolt on the lower side.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)
Zero mm
(Zero in)Zero mm
(Zero in)
9. Install:
Lights switch 1
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
10. Install:
“ENGINE STOP” button 1
Clutch lever holder 2
Bolt (clutch lever holder) 3
Hot starter lever holder 4
Bolt (hot starter lever holder) 5
Clamp 6
NOTE:
The “ENGINE STOP” button, clutch lever
holder and clamp should be installed accord-
ing to the dimensions shown.
Pass the “ENGINE STOP” button lead in the
middle of the clutch lever holder.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)

5 - 46
CHAS
EC560000
STEERING
Extent of removal:1 Under bracket removal2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Refer to “HANDLEBAR” section. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Headlight
Handlebar
Hose guide
Front fender
1 Coupler bracket 1
2 Trip meter 1
3 Main switch 1 Disconnect the main switch lead.
4 Steering shaft cap 1
5 Steering shaft nut 1
6 Front fork 2 Refer to “FRONT FORK” section.
7 Handle crown 1
8 Ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
9 Under bracket 1
10 Ball race cover 1
2
1
STEERING

5 - 61
CHASREAR SHOCK ABSORBER
Extent of removal Order Part name Q’ty Remarks
Disconnect the starter relay cou-
pler.
Starter motor lead Disconnect at the starter relay side.
1 Locking tie 2
2 Taillight coupler 1
3 Starting circuit cut-off relay cou-
pler1
4 Plastic band 2
5 Clamp (air filter joint) 1 Only loosening.
6 Rear frame 1
7 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
8 Bolt (rear shock absorber-frame) 1
9 Rear shock absorber 1
10 Locknut 1 Only loosening.
11 Adjuster 1 Only loosening.
12 Spring guide (lower) 1
13 Spring guide (upper) 1
2
1

5 - 68
CHAS
8. Install:
Plastic band 1
Starting circuit cut-off relay coupler 2
Taillight coupler 3
Locking tie 4
3
2
1
4
REAR SHOCK ABSORBER

6 - 1
–+ELEC

ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1
Headlight
2
“ENGINE STOP”
button
3
Clutch switch
4
Diode
5
Starter relay diode
6
TPS (throttle posi-
tion sensor)
7
Starter relay
8
Fuse
9
Starting circuit
cut-off relay
0
Taillight
A
Neutral switch
B
Starter motor
C
AC magneto
D
Rectifier/regulator
E
Ignition coil
F
Spark plug
G
Start switch
H
Lights switch
I
Main switch
J
CDI unit
K
Battery
COLOR CODE
B.......................Black
Br .....................Brown
Gy ....................Gray
L .......................Blue
O ......................Orange
R ......................Red
Sb.....................Sky blue
W......................White
Y.......................Yellow
B/L....................Black/Blue
EC612000
WIRING DIAGRAM
1 2345
678
90
A B
CDEFGH
I
J
K
WR
WR
R
BR/BBr
R
BR/BBr
RW
L/RL/BBB
SbL/W
WY
YW
L/YBBB
WY
RYW
R
LY
B
YLB/L
B
B
ON
OFF
10A
BB
OFF
ON
OFF
STARTSTART
R-BrL/W
BLY
YLB-LB
B
BrL/W
BrL/W
L/B-LB
YL
B
L-B
L/WSb
B/WBBB
W/RB/W
R/BGyBrL/W
ON
STOP
OB
LYSbB/L
W RBrB/W
L/BGyWR/B
B O
L/YSbL/R
R W
Y W
Y W
Y B
B
L
L L
L B
B
B
RRR/B
B Br B
B B B B
L/W
R
R
R R B
R
BrBr
L/W L/W
Br B
L/B
L/B
L/R

Br
R/B
L/B L/W
B/W
W W/RW
RO
L
Y
B/L
O

B
L
Y
B/LSbL/WB/W
B
L/R L/Y L/Y
B
SbSbL/W
BGy
SbBB/LYO
L
∗2
O B
L YL/W
B/L
∗1
C
HD
BI
5
9
G3 4
A 2J
EF
6 7
K8
1
0
∗
2
∗1
∗2: Except for USA
∗1: For USA

B/W .................. Black/White
L/B ................... Blue/Black
L/R ................... Blue/Red
L/Y ................... Blue/Yellow
L/W .................. Blue/White
R/B................... Red/Black

6 - 5
–+ELECIGNITION SYSTEM
MAIN SWITCH INSPECTION
1. Inspect:
Main switch conduct
Continuous while the main switch is moved to
“OFF” → Replace.
Not continuous while the main switch is moved
to “ON” → Replace.
2. Inspect:
Main switch indicator light
Use 12 V battery.
Indicator light does not come on → Replace.
3. Inspect:
Rubber part a
Tears/damage → Replace. Tester (+) lead → Red lead 1
Tester (–) lead → Brown lead 2
R
1Br
2Tester selector
position
ON
Ω × 1
OFF
Battery (+) lead → Red/Black lead 1
Battery (–) lead → Black lead 2
a
EC626002
IGNITION COIL INSPECTION
1. Remove the ignition coil cap.
2. Inspect:
Primary coil resistance
Out of specification → Replace.
Tester (+) lead → Orange lead 1
Tester (–) lead → Black lead 2
Primary coil
resistanceTester selector
position
0.08 ~ 0.10 Ω at
20 ˚C (68 ˚F)Ω × 1