2008 YAMAHA YZ450F Owners Manual

Page 57 of 188

YAMAHA YZ450F 2008  Owners Manual 3-11
ENGINE
BLE". The field where these two 
coordinates intersect shows the 
new pad number to use.
Use the new pad number only as a 
guide when verifying the valve clear-
ance adjustment.
f. Install

Page 58 of 188

YAMAHA YZ450F 2008  Owners Manual 3-12
ENGINE
INTAKE
EXHAUST

Page 59 of 188

YAMAHA YZ450F 2008  Owners Manual 3-13
CHASSIS
CHASSIS
BLEEDING THE HYDRAULIC 
BRAKE SYSTEM
Bleed the brake system if:
•The system has been disassem-
bled.
• A brake hose has been loosened 
or removed.
• The brake fluid is very

Page 60 of 188

YAMAHA YZ450F 2008  Owners Manual 3-14
CHASSIS
CHECKING AND REPLACING THE 
FRONT BRAKE PADS
1. Inspect:
• Brake pad thickness "a"
Out of specification
→Replace as 
a set.
2. Replace:
• Brake pad
Brake pad replacement steps:
a. R

Page 61 of 188

YAMAHA YZ450F 2008  Owners Manual 3-15
CHASSIS
b. Loosen the pad pin "3".
c. Remove the rear wheel "4" and 
brake caliper "5".
Refer to "FRONT WHEEL AND 
REAR WHEEL" section in the 
CHAPTER 5.
d. Remove the pad pin "6" and brake 
pads

Page 62 of 188

YAMAHA YZ450F 2008  Owners Manual 3-16
CHASSIS
CHECKING THE DRIVE CHAIN
1. Measure:
• Drive chain length (15 links) "a"
Out of specification
→Replace.
• While measuring the drive chain 
length, push down on the drive 
chain to i

Page 63 of 188

YAMAHA YZ450F 2008  Owners Manual 3-17
CHASSIS
CHECKING THE FRONT FORK
1. Inspect:
• Front fork smooth action
Operate the front brake and 
stroke the front fork.
Unsmooth action/oil leakage
→
Repair or replace.
CLEANING THE FRONT

Page 64 of 188

YAMAHA YZ450F 2008  Owners Manual 3-18
CHASSIS
ADJUSTING THE REAR SHOCK 
ABSORBER SPRING PRELOAD
1. Elevate the rear wheel by placing 
the suitable stand under the en-
gine.
2. Remove:
• Rear frame
3. Loosen:
• Locknut "1"
4. Adju