2014 YAMAHA YZ450F tire type

CHASSIS SPECIFICATIONS
2-8
EAS1SL1054
CHASSIS SPECIFICATIONS
Chassis
Frame type Semi double cradle
Caster angle 27.08 ° (USA) (CAN)
27.50 ° (EUR)
27.67 ° (JPN)
27.58 ° (AUS) (NZL) (ZAF)
Trail 120 mm (4.7 in) (USA) (CAN)
122 mm (4.8 in) (EUR)
124 mm (4.9 in) (JPN) (AUS) (NZL) (ZAF)
Front wheel
Wheel type Spoke wheel
Rim size 21  1.60
Rim material Aluminum
Wheel travel 310.0 mm (12.20 in)
Radial wheel runout limit 2.0 mm (0.08 in)
Lateral wheel runout limit 2.0 mm (0.08 in)
Wheel axle bending limit 0.50 mm (0.02 in)
Rear wheel
Wheel type Spoke wheel
Rim size 19  2.15
Rim material Aluminum
Wheel travel 315.0 mm (12.40 in)
Radial wheel runout limit 2.0 mm (0.08 in)
Lateral wheel runout limit 2.0 mm (0.08 in)
Wheel axle bending limit 0.50 mm (0.02 in)
Front tire
Type With tube
Size 80/100-21 51M
Manufacturer/model DUNLOP/MX51FA (USA) (CAN)
PIRELLI/MID SOFT 32 (EUR)
BRIDGESTONE/M601 (JPN)
DUNLOP/MX51FA (AUS) (NZL) (ZAF)
Rear tire
Type With tube
Size 120/80-19 63M (USA) (CAN)
110/90-19 62M (EUR) (JPN)
120/80-19 63M (AUS) (NZL) (ZAF)
Manufacturer/model DUNLOP/MX51 (USA) (CAN)
PIRELLI/MID SOFT 32 (EUR)
BRIDGESTONE/M602 (JPN)
DUNLOP/MX51 (AUS) (NZL) (ZAF)
Tire air pressure (measured on cold tires)
Front 100 kPa (1.00 kgf/cm2, 15 psi)
Rear 100 kPa (1.00 kgf/cm2, 15 psi)
Front brake
Type Single disc brake
Operation Right hand operation
Front disc brake
Disc outside diameter  thickness 250.0  3.0 mm (9.84  0.12 in)

FRONT BRAKE
4-18
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu
-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When pouring the brake fluid, be careful
that water does not enter the reservoir.
Water will significantly lower the boiling
point of the brake fluid and could cause
vapor lock.
ECA13540
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
5. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
6. Check:
• Brake fluid level
The minimum level mark or below  Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-26.
7. Check:
• Brake lever free play
Refer to “ADJUSTING THE FRONT
BRAKE” on page 3-22.
• Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
EAS1SL1144REMOVING THE FRONT BRAKE MASTER
CYLINDER
TIP
Before removing the front brake master cylin-
der, drain the brake fluid from the entire brake
system.
1. Remove:
• Union bolt
• Copper washers
• Brake hoses
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EAS1SL1145CHECKING THE FRONT BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder “1”
Damage/scratches/wear  Replace.
• Brake fluid delivery passages “2”
(brake master cylinder body)
Obstruction  Blow out with compressed
air.
2. Check:
• Brake master cylinder kit
Damage/scratches/wear  Replace.
3. Check:
• Brake master cylinder reservoir cap
4. Check:
• Brake hoses
Cracks/damage/wear  Replace.
EAS1SL1146ASSEMBLING THE FRONT BRAKE MAS-
TER CYLINDEREWA13520
WARNING
• Before installation, clean and lubricate the
internal parts. Use new brake fluid for
cleaning and lubricating.
• Never use solvents on internal brake com-
ponents.
1. Wash the brake master cylinder and the
brake master cylinder kit with brake fluid.
2. Install:
• Primary cylinder cup “1”
• Secondary cylinder cup “2”
Install to the brake master cylinder piston
“3.”
EWA13520
Recommended brake fluid
DOT 4
1
2
New
New

REAR BRAKE
4-28
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu
-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When pouring the brake fluid, be careful
that water does not enter the reservoir.
Water will significantly lower the boiling
point of the brake fluid and could cause
vapor lock.
ECA13540
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
5. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
6. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-26.
7. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
EAS1SL1157
REMOVING THE REAR BRAKE MASTER
CYLINDER
TIP
Before removing the rear brake master cylin-
der, drain the brake fluid from the entire brake
system.
1. Remove:
• Union bolt
• Copper washers
• Brake hose
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EAS1SL1158CHECKING THE REAR BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder “1”
Damage/scratches/wear  Replace.
• Brake fluid delivery passages “2”
(brake master cylinder body)
Obstruction  Blow out with compressed
air.
2. Check:
• Brake master cylinder kit
Damage/wear  Replace
3. Check:
• Master cylinder reservoir cap
Crack/damage  Replace.
• Brake master cylinder reservoir diaphragm
holder
• Brake master cylinder reservoir diaphragm
Crack/damage  Replace.
4. Check:
• Brake hoses
Cracks/damage/wear  Replace.
EAS1SL1159
a
1
2

CHASSIS
10-1
EAS1SL1365
CHASSIS
EAS1SL1366SELECTION OF THE SECONDARY REDUC-
TION RATIO (SPROCKET)
reduction ratio>
• It is generally said that the secondary gear ra-
tio should be reduced for a longer straight por-
tion of a speed course and should be
increased for a course with many corners. Ac
-
tually, however, as the speed depends on the
ground condition of the day of the race, be
sure to run through the circuit to set the ma
-
chine suitable for the entire course.
• In actuality, it is very difficult to achieve set-
tings suitable for the entire course and some
settings may be sacrificed. Thus, the settings
should be matched to the portion of the
course that has the greatest effect on the race
result. In such a case, run through the entire
course while making notes of lap times to find
the best balance; then, determine the second
-
ary reduction ratio.
• If a course has a long straight portion where a
machine can run at maximum speed, the ma
-
chine is generally set such that it can develop
its maximum revolutions toward the end of the
straight line, with care taken to avoid the en
-
gine over-revving.
TIP
Riding technique varies from rider to rider and
the performance of a machine also vary from
machine to machine. Therefore, do not imitate
other rider's settings from the beginning but
choose your own setting according to the level
of your riding technique.
EAS1SL1367
DRIVE AND REAR WHEEL SPROCKETS
SETTING PARTS
EAS1SL1368
Secondary reduction ratio = Number of
rear wheel sprocket teeth/Number of
drive sprocket teeth
Secondary reduction ra-
tio
3.769 (49/13)
Part nameTypePart number
Drive sprocket “1”
(STD)13T9383E-13233
Rear wheel
sprocket “2”
48T5GS-25448-50
(STD)49T17D-25449-50
50T5TJ-25450-80
52T5TJ-25452-80