2003 YAMAHA YZ450F boot

IMPORTANT NOTICE
THIS MACHINE IS DESIGNED STRICTLY
FOR COMPETITION USE, ONLY ON A
CLOSED COURSE. It is illegal for this
machine to be operated on any public street,
road, or highway. Off-road use on public lands
may also be illegal. Please check local regula-
tions before riding.
1. THIS MACHINE IS TO BE OPERATED
BY AN EXPERIENCED RIDER ONLY.
Do not attempt to operate this
machine at maximum power until you
are totally familiar with its character-
istics.
2. THIS MACHINE IS DESIGNED TO BE
RIDDEN BY THE OPERATOR ONLY.
Do not carry passengers on this
machine.
3. ALWAYS WEAR PROTECTIVE
APPAREL.
When operating this machine, always
wear an approved helmet with gog-
gles or a face shield. Also wear heavy
boots, gloves, and protective cloth-
ing. Always wear proper fitting cloth-
ing that will not be caught in any of
the moving parts or controls of the
machine.
4. ALWAYS MAINTAIN YOUR MACHINE
IN PROPER WORKING ORDER.
For safety and reliability, the machine
must be properly maintained. Always
perform the pre-operation checks
indicated in this manual. Correcting a
mechanical problem before you ride
may prevent an accident.
5. GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refu-
eling. Take care to not spill any gaso-
line on the engine or exhaust system.
Never refuel in the vicinity of an open
flame, or while smoking.
SAFETY INFORMATION

GEN
INFO
1 - 13
DECOMPRESSION LEVER
DECOMPRESSION LEVER
An auto decompression device is standard equipment on the machine. There is no need to operate
the decompression lever in normal use because the auto decompression device is working.
Use the decompression lever when the engine fails to start or when you want to step down the kick
starter with a lighter force.
For engine starting failure, refer to “STARTING AND BREAK-IN”.
Installation (Supplied for Europe and optional for other destinations)
For installation, follow the steps below.
Order Part name Q’ty Remarks
1 Oil seal 1
2 Torsion spring 1
3 Decompression shaft 1
4 Decompression cable guide 1
5 Flange bolt 1 M 6 × 1.0 [L=14 mm (0.55 in)]
6 Decompression cable 1
7 Decompression lever 1
8 Boot 1
9 Decompression lever holder (upper) 1
10 Collar 1
11 Panhead screw 1 M 5 × 0.8 [L=20 mm (0.79 in)]
12 Nut 1 M 5 × 0.8
13 Decompression lever holder (lower) 1
14 Hexagon bolt 2 M 5 × 0.8 [L=16 mm (0.63 in)]
14
13
11
10 8
7
9
12 6
5
4
1
2
3
T R..10 Nm (1.0 m •
kg, 7.2 ft • Ib)
T R..7 Nm (0.7 m •
kg, 5.1 ft • Ib)
T R..4 Nm (0.4 m •
kg, 2.9 ft • Ib)
B
B
B
B
BE

1 - 15
GEN
INFO
DECOMPRESSION LEVER
3. Install:
Decompression lever 1
Boot 2
Decompression lever holder (upper) 3
Collar 4
Screw 5
Nut 6
NOTE:
Install the collar with its thread portion a fac-
ing the nut and with the lithium soap base
grease applied to its outer circumference.
4. Install:
Decompression lever holder (lower) 1
Bolt (decompression lever holder) 2
NOTE:
The decompression lever holder should be
installed according to the dimension as shown.
a
B
5
4
3
6
2 1
5 mm (0.2 in)
1
2
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
5. Install:
Decompression cable 1
NOTE:
Apply the lithium soap base grease on the
decompression lever sliding surface and the
decompression cable end.
Install the decompression cable after pass-
ing it through the boot hole a.
6. Inspect:
Decompression cable routing
Refer to “CABLE ROUTING DIAGRAM”
section in the CHAPTER 2.
7. Adjust:
Decompression lever free play
Refer to “DECOMPRESSION LEVER
ADJUSTMENT” section.
8. Install all of the removed parts.
1 a
B
E

5 - 13
CHASFRONT BRAKE AND REAR BRAKE
EC5A8300
MASTER CYLINDER DISASSEMBLY
ÅFront
ıRear
Extent of removal:1 Front master cylinder disassembly2 Rear master cylinder disassembly
Extent of removal Order Part name Q’ty Remarks
MASTER CYLINDER DISAS-
SEMBLY
1 Master cylinder cap 1
2 Diaphragm 1
3 Master cylinder boot 1
4 Circlip 1 Use a long nose circlip pliers.
5 Plain washer 1
6 Push rod 1
7 Master cylinder kit
1
12
12

5 - 20
CHASFRONT BRAKE AND REAR BRAKE
3. Install:
Spring 1
To master cylinder piston 2.
NOTE:
Install the spring at the smaller dia. side.
ÅFront
ıRear
Åı
4. Install:
[Front]
Master cylinder kit 1
Plain washer 2
Circlip 3
Master cylinder boot 4
To master cylinder 5.
[Rear]
Master cylinder kit 1
Push rod 2
Circlip 3
Master cylinder boot 4
To master cylinder 5.
NOTE:
Apply the brake fluid on the master cylinder
kit.
Apply the lithium soap base grease on the tip
of the push rod.
When installing the circlip, use a long nose
circlip pliers.
ÅFront
ıRear
EC5A5310
Front master cylinder
1. Install:
Master cylinder 1
Master cylinder bracket 2
Bolt (master cylinder bracket) 3
NOTE:
Install the bracket so that the arrow mark a
face upward.
First tighten the bolts on the upper side of the
master cylinder bracket, and then tighten the
bolts on the lower side.
Å
ı
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)