ABS YAMAHA YZ450F 2009 Owners Manual

CONTENTS
CHAPTER 1
GENERAL
INFORMATION
DESCRIPTION ................. 1-1
MACHINE
IDENTIFICATION ............. 1-2
INCLUDED PARTS .......... 1-2
IMPORTANT
INFORMATION................. 1-2
CHECKING OF
CONNECTION .................. 1-3
SPECIAL TOOLS ............. 1-4
CONTROL FUNCTIONS .. 1-8
STARTING AND
BREAK-IN ........................ 1-8
TORQUE-CHECK
POINTS........................... 1-11
CLEANING AND
STORAGE ...................... 1-12
CHAPTER 2
SPECIFICATIONS
GENERAL
SPECIFICATIONS ............ 2-1
MAINTENANCE
SPECIFICATIONS ............ 2-3
TIGHTENING
TORQUES ...................... 2-10
LUBRICATION
DIAGRAMS .................... 2-16
CABLE ROUTING
DIAGRAM ....................... 2-18
CHAPTER 3
REGULAR
INSPECTION AND
ADJUSTMENTS
MAINTENANCE
INTERVALS ...................... 3-1
PRE-OPERATION
INSPECTION AND
MAINTENANCE................ 3-5
ENGINE ............................ 3-6
CHASSIS ........................ 3-14
ELECTRICAL ................. 3-24
CHAPTER 4
ENGINE
SEAT, FUEL TANK AND
SIDE COVERS.................. 4-1
EXHAUST PIPE AND
SILENCER ........................ 4-3
RADIATOR ....................... 4-5
CARBURETOR................. 4-7
CAMSHAFTS.................. 4-14
CYLINDER HEAD........... 4-19
VALVES AND
VALVE SPRINGS ........... 4-22
CYLINDER AND
PISTON ........................... 4-26
CLUTCH ......................... 4-29
OIL FILTER ELEMENT
AND WATER PUMP ....... 4-33
BALANCER .................... 4-37
OIL PUMP ....................... 4-39
KICK SHAFT AND
SHIFT SHAFT ................. 4-42
CDI MAGNETO............... 4-47
ENGINE REMOVAL ....... 4-49
CRANKCASE AND
CRANKSHAFT ............... 4-53
TRANSMISSION,
SHIFT CAM AND
SHIFT FORK................... 4-59
CHAPTER 5
CHASSIS
FRONT WHEEL AND
REAR WHEEL ..................5-1
FRONT BRAKE AND
REAR BRAKE ..................5-6
FRONT FORK ................. 5-16
HANDLEBAR..................5-24
STEERING ......................5-28
SWINGARM ....................5-31
REAR SHOCK
ABSORBER ....................5-36
CHAPTER 6
ELECTRICAL
ELECTRICAL
COMPONENTS AND
WIRING DIAGRAM ...........6-2
IGNITION SYSTEM...........6-3
THROTTLE POSITION
SENSOR SYSTEM ...........6-6
CHAPTER 7
TUNING
ENGINE.............................7-1
CHASSIS ..........................7-6

1-11
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Concerning the tightening torque, refer to "TIGHTENING TORQUES" section in the CHAPTER 2.
Frame construction Frame to rear frame
Combined seat and fuel tank Fuel tank to frame
Exhaust system Silencer to rear frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear For link type Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Installation of rear shock absorber Rear shock absorber to frame
Installation of swingarm Tightening of pivot shaft
Wheel Installation of wheel Front Tightening of wheel axle
Tightening of axle holder
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Brake Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Fuel system Fuel tank to fuel cock
Lubrication system Tightening of oil hose clamp

2-2
GENERAL SPECIFICATIONS
Fuel:
Type Premium unleaded gasoline only with a research octane
number of 95 or higher.
Tank capacity 7.0 L (1.54 Imp gal, 1.85 US gal)
Carburetor:
Type FCR-MX39
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7–0.8 mm (0.028–0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 61/23 (2.652)
Secondary reduction system Chain drive
Secondary reduction ratio 49/13 (3.769)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio:
1st 27/14 (1.929)
2nd 23/15 (1.533)
3rd 23/18 (1.278)
4th 24/22 (1.091)
5th 20/21 (0.952)
Chassis: USA, CDN, AUS, NZ, ZA EUROPE
Frame type Semi double cradle←
Caster angle 26.9° 26.8°
Trail 115.7 mm (4.56 in) 114.2 mm (4.50 in)
Tire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 120/80-19 63M (For USA, CDN, ZA, AUS, NZ)
110/90-19 62M (For EUROPE)
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2, 15 psi)
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper

2-8
MAINTENANCE SPECIFICATIONS
CHASSISLubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm (0.007
in)
Bypass valve setting pressure 40–80 kPa (0.4–0.8 kg/cm
2, 5.69–11.38
psi)----
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height 240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.56 L (0.49 Imp qt, 0.59 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN EUROPE, AUS, NZ, ZA
Front fork travel 300 mm (11.8 in)←----
Fork spring free length 454 mm (17.9 in)←449 mm (17.7
in)
Spring rate, STD K = 4.6 N/mm (0.469 kg/
mm, 26.3 lb/in)←----
Optional spring Yes←----
Oil capacity 541 cm
3 (19.0 lmp oz,
18.3 US oz)531 cm3 (18.7 lmp oz,
18.0 US oz)----
Oil grade Suspension oil "S1"←----
Inner tube outer diameter 48 mm (1.89 in)←----
Front fork top end 5 mm (0.20 in)←----
Rear suspension: USA, CDN EUROPE, AUS, NZ, ZA
Shock absorber travel 131.5 mm (5.18 in)←----
Spring free length Approx.275 mm (10.83
in)←----
Fitting length*
I.D. mark (Pink/1) 266 mm (10.47 in) 263 mm (10.35 in) ----
I.D. mark (Pink/2) 272 mm (10.71 in) 269 mm (10.59 in) ----
I.D. mark (Pink/3) 263.5 mm (10.37 in) 260.5 mm (10.26 in) ----

2-13
TIGHTENING TORQUES
Brake lever mounting nut M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
△Cable guide (front brake hose) and under bracket M6 × 1.0 1 4 0.4 2.9
△Front brake hose union bolt (brake master cylinder) M10 × 1.25 1 30 3.0 22
△Front brake hose union bolt (brake caliper) M10 × 1.25 1 30 3.0 22
△Front brake caliper and front fork M8 × 1.25 2 28 2.8 20
△Brake caliper (front and rear) and pad pin plug M10 × 1.0 2 3 0.3 2.2
△Brake caliper (front and rear) and pad pin M10 × 1.0 2 18 1.8 13
△Brake caliper (front and rear) and bleed screw M8 × 1.25 2 6 0.6 4.3
△Front wheel axle and axle nut M16 × 1.5 1 105 10.5 75
△Front wheel axle holder M8 × 1.25 4 21 2.1 15
△Front brake disc and wheel hub M6 × 1.0 6 12 1.2 8.7
△Rear brake disc and wheel hub M6 × 1.0 6 14 1.4 10
△Footrest bracket and frame M10 × 1.25 4 55 5.5 40
△Brake pedal mounting M8 × 1.25 1 26 2.6 19
△Rear brake master cylinder and frame M6 × 1.0 2 10 1.0 7.2
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△Rear brake hose union bolt (brake caliper) M10 × 1.25 1 30 3.0 22
△Rear brake hose union bolt (brake master cylinder) M10 × 1.25 1 30 3.0 22
△Rear wheel axle and axle nut M22 × 1.5 1 135 13.5 98
△Driven sprocket and wheel hub M8 × 1.25 6 42 4.2 30
△Nipple (spoke) — 72 3 0.3 2.2
△Disc cover and rear brake caliper M6 × 1.0 2 10 1.0 7.2
△Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 19 1.9 13
Engine mounting:
△Upper engine bracket and frame M10 × 1.25 4 55 5.5 40
△Lower engine bracket and frame M8 × 1.25 4 34 3.4 24
△Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
△Engine and engine bracket (upper) M10 × 1.25 1 55 5.5 40
△Engine and frame (lower) M10 × 1.25 1 53 5.3 38
△Engine guard M6 × 1.0 1 10 1.0 7.2
Lower engine guard M6 × 1.0 3 10 1.0 7.2
CDI unit bracket M6 × 1.0 2 7 0.7 5.1
Cable guide and CDI unit bracket M5 × 0.8 2 4 0.4 2.9
Cable guide and frame M5 × 0.8 1 5 0.5 3.6
△Pivot shaft and nut M16 × 1.5 1 85 8.5 61
△Relay arm and swingarm M14 × 1.5 1 70 7.0 50
△Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
△Connecting rod and frame M14 × 1.5 1 80 8.0 58
△Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
△Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
△Rear frame and frame (upper) M8 × 1.25 1 38 3.8 27
△Rear frame and frame (lower) M8 × 1.25 2 32 3.2 23Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-19
CABLE ROUTING DIAGRAM
E. Pass the clutch cable in front of
the radiator mounting boss.
F. Install the connector cover so
that it does not come in between
the radiator hose 1 and radiator.
G. Pass the fuel hose on the out-
side of throttle position sensor
lead.
H. Pass the carburetor breather
hoses and overflow hose so that
all there hoses do not contact
the rear shock absorber.

2-23
CABLE ROUTING DIAGRAM
1. Brake master cylinder
2. Brake hose holder
3. Brake hose
A. Install the brake hose so that its
pipe portion directs as shown
and lightly touches the projec-
tion on the brake caliper.
B. Pass the brake hose into the
brake hose holders.C. If the brake hose contacts the
spring (rear shock absorber),
correct its twist.
D. Install the brake hose so that its
pipe portion directs as shown
and lightly touches the projec-
tion on the brake master cylin-
der.

3-3
MAINTENANCE INTERVALS
FUEL TANK, COCK
Clean and inspect●●
BRAKES
Adjust lever position and pedal
height●●
Lubricate pivot point●●
Check brake disc surface●●
Check fluid level and leakage●●
Retighten brake disc bolts, cali-
per bolts, master cylinder bolts
and union bolts●●
Replace pads●
Replace brake fluid●Every one year
FRONT FORKS
Inspect and adjust●●
Replace oil●●Suspension oil "S1"
Replace oil seal●
FRONT FORK OIL SEAL AND
DUST SEAL
Clean and lube●●Lithium base grease
PROTECTOR GUIDE
Replace●
REAR SHOCK ABSORBER
Inspect and adjust●●
Lube●(After
rain
ride)●Molybdenum disulfide grease
Replace spring seat●Every one year
Retighten●●
DRIVE CHAIN GUIDE AND
ROLLERS
Inspect●●
SWINGARM
Inspect, lube and retighten●●Molybdenum disulfide grease
RELAY ARM, CONNECTING
ROD
Inspect, lube and retighten●●Molybdenum disulfide grease
STEERING HEAD
Inspect free play and retighten●●
Clean and lube●Lithium base grease
Replace bearing● ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks

3-5
PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap. Check the cool-
ing system for leakage.P.3-6 – 7
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage.P.1-8
Engine oilCheck that the oil level is correct. Check the crankcase and oil line
for leakage.P.3-9 – 10
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-7
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-7 – 8
Brakes Check the play of front brake and effect of front and rear brake. P.3-14 – 16
Drive chainCheck drive chain slack and alignment. Check that the drive chain
is lubricated properly.P.3-17 – 18
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-20 – 21
SteeringCheck that the handlebar can be turned smoothly and have no ex-
cessive play.P.3-21 – 22
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage.
P.3-18 – 20
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.—
Exhaust pipe Check that the exhaust pipe is tightly mounted and has no cracks. P.4-3 – 4
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-17
Lubrication Check for smooth operation. Lubricate if necessary. P.3-23
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-11
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-3
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs be-
fore racing? Are inspection and maintenance completely done?P.7-1 – 10

3-19
CHASSIS
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
CHECKING THE REAR SHOCK
ABSORBER
1. Inspect:
• Swingarm smooth action
Abnormal noise/unsmooth action
→Grease the pivoting points or
repair the pivoting points.
Damage/oil leakage→Replace.
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. Measure:
• Spring fitting length• The I.D. mark "a" is marked at the
end of the spring.
• Spring specification varies accord-
ing to the difference in the produc-
tion lot.
4. Adjust:
• Spring preload
Adjustment steps:
a. Loosen the locknut "1".
b. Loosen the adjuster "2" until there
is some clearance between the
spring and adjuster.
c. Measure the spring free length
"a".
d. Turn the adjuster "2".
ŒBe sure to remove all dirt and mud
from around the locknut and adjust-
er before adjustment.
• The length of the spring (installed)
changes 1.5 mm (0.06 in) per turn
of the adjuster.
Never attempt to turn the adjuster
beyond the maximum or minimum
setting.
e. Tighten the locknut.
5. Install:
• Rear frame (upper)
• Rear frame (lower)
ADJUSTING THE REAR SHOCK
ABSORBER REBOUND DAMPING
FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1". Standard position:
12 clicks out
* 10 clicks out
* Except for USA and CDN
Standard fitting length:
I.D. MARK/
Q'TYLength
Pink/1
Pink/2
Pink/3266 mm
(10.47 in)
*263 mm
(10.35 in)
272 mm
(10.71 in)
*269 mm
(10.59 in)
263.5 mm
(10.37 in)
*260.5 mm
(10.26 in)
* Except for USA and CDN
Stiffer →Increase the spring pre-
load. (Turn the adjuster "2" in.)
Softer→Decrease the spring pre-
load. (Turn the adjuster "2"
out.)
Extent of adjustment:
Maximum Minimum
Position in
which the
spring is turned
in 13 mm (0.51
in) from its free
length.Position in
which the
spring is turned
in 1.5 mm (0.06
in) from its free
length.
Locknut:
30 Nm (3.0 m•kg, 22
ft•lb)
Rear frame (upper):
38 Nm (3.8 m•kg, 27
ft•lb)
Rear frame (lower):
32 Nm (3.2 m•kg, 23
ft•lb)
Stiffer "a" →Increase the re-
bound damping force. (Turn
the adjuster "1" in.)
Softer "b" →Decrease the re-
bound damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)