clutch YAMAHA WR 450F 2003 Service Manual

4 - 97
ENGCRANKCASE AND CRANKSHAFT
5. Install:
Dowel pin 1
O-ring 2
Crankcase (right)
To crankcase (left).
NOTE:
Fit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
When installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
New
6. Tighten:
Hose guide 1
Clutch cable holder 2
Bolt (clutch cable holder)
Bolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
7. Install:
Oil delivery pipe
O-ring
Bolt (oil delivery pipe)
8. Install:
Timing chain
Timing chain guide (rear)
Bolt (timing chain guide)
9. Remove:
Sealant
Forced out on the cylinder mating surface.
10. Apply:
Engine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
Crankshaft and transmission operation.
Unsmooth operation → Repair.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

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 - 45
CHASHANDLEBAR
11. Install:
Clutch cable 1
Hot starter cable 2
NOTE:
Apply the lithium soap base grease on the
clutch cable end and hot starter cable end.
12. Adjust:
Clutch lever free play
Refer to “CLUTCH ADJUSTMENT”
section in the CHAPTER 3.
Hot starter lever free play
Refer to “HOT STARTER LEVER
ADJUSTMENT” section in the CHAP-
TER 3.
13. Fasten the hot starter cable 1 and clutch
cable 2 with a clamp 3.
1
2
3
14. Insert the end of the fuel breather hose
1 into the hole in the steering shaft cap
2.
1
2

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 - 7
–+ELEC
ELECTRIC STARTING SYSTEM
STARTING CIRCUIT CUT-OFF SYSTEM
OPERATION
If the main switch is set to “ON”, the starter
motor can only operate if at least one of the
following conditions is met:
The transmission is in neutral (the neutral
switch is closed).
The clutch lever is pulled to the handlebar
(the clutch switch is closed).
The starting circuit cut-off relay prevents the
starter motor from operating when neither of
these conditions has been met. In this
instance, the starting circuit cut-off relay is
open so current cannot reach the starter
motor. When at least one of the above condi-
tions has been met the starting circuit cut-off
relay is closed and the engine can be started
by pressing the start switch.
WHEN THE TRANSMISSION IS
IN NEUTRAL
WHEN THE CLUTCH LEVER IS
PULLED TO THE HANDLEBAR
1Battery
2Main fuse
3Main switch
4Starting circuit cut-off relay
5Start switch
6Diode
7Clutch switch
8Neutral switch
9Starter relay
0Starter motor
12
M
3
4
5
8 76 9
0
ELECTRIC STARTING SYSTEM

–+ELEC
6 - 8
ELECTRIC STARTING SYSTEM
INSPECTION STEPS
If the starter motor will not operate, use the following inspection steps.
*1 marked: Refer to “FUSE INSPECTION” section in the CHAPTER 3.
*2 marked: Refer to “BATTERY INSPECTION AND CHARGING” section in the CHAPTER 3.
*3 marked: Refer to “MAIN SWITCH INSPECTION” section.
*4 marked: Refer to “NEUTRAL SWITCH INSPECTION” section.
NOTE:
Remove the following parts before inspection.
1) Seat
2) Rear fender
Use 12 V battery in this inspection.
Use the following special tools in this inspection.
Pocket tester:
YU-3112-C/90890-03112
*1 Check fuseReplace fuse and
check wire harness.
*2 Check battery Recharge or replace.
Check each coupler and
wire connection.Repair or replace.
*3 Check main switch. Replace.
Check starter motor
operation.Repair or replace.
Check starting circuit
cut-off relay.Replace.
Check starter relay. Replace.
*4 Check neutral switch. Replace.
Check clutch switch. Replace.
Check diode. Replace.
Check start switch. Replace.
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good

6 - 10
–+ELECELECTRIC STARTING SYSTEM
STARTER RELAY INSPECTION
1. Remove:
Starter relay
2. Inspect:
Starter relay conduct
Use 12 V battery.
Continuous while not connected to the battery
→ Replace.
Not continuous while connected to the battery
→ Replace.Battery (+) lead →
Starter relay terminal 1
Battery (–) lead →
Starter relay terminal 2
Tester (+) lead →
Starter relay terminal 3
Tester (–) lead →
Starter relay terminal 4
Ter-
minal
3
Ter-
minal
4Tester selec-
tor position
Connected
to battery
Ω × 1Not
connected
to battery
CLUTCH SWITCH INSPECTION
1. Inspect:
Clutch switch continuity
No continuous while being pulled → Replace.
Continuous while being freed → Replace. Tester (+) lead → Black lead 1
Tester (–) lead → Black lead 2
B
1B
2Tester selec-
tor position
PULL
Ω × 1
FREE

6 - 12
–+ELECELECTRIC STARTING SYSTEM
STARTER MOTOR
0
9
56
7
5 0 8
9
4
3
2
1
New
New
New
B
5
1
Extent of removal:1 Starter motor disassembly
Extent of removal Order Part name Q’ty Remarks
STARTER MOTOR REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Crankcase cover (left) Refer to “AC MAGNETO AND
STARTER CLUTCH” section in the
CHAPTER 4.
1 Starter motor 1
STARTER MOTOR DISASSEM-
BLY
1Starter motor front cover 1
2Washer (starter motor front
cover)1
3Plain washer 1
4Circlip 1
5O-ring
3
1