2011 YAMAHA YZ450F lock

2-21
CABLE ROUTING DIAGRAM
1. Clutch cable
2. Throttle cable (return)
3. Throttle cable (pull)
4. Cable holder
5. Clamp
6. Rectifier/regulator
7. Ignition coil
8. Ignition coil coupler
9. AC magneto coupler
10. Radiator hose 2
11. Ground lead terminal
12. Plug cap
13. Ignition coil bracket
14. Clamp (lock)
15. Clamp (clip)
16. AC magneto lead
17. ECU bracketA. Pass the clutch cable, throttle
cables, and engine stop switch
lead through the cable holder.
Pass the clutch cable through
the lower guide only.
B. Route the engine stop switch
lead to the inside of the clip.
C. Fasten the rectifier/regulator
lead and engine stop switch lead
(wire harness end).
D. Insert the projection on the en-
gine stop switch coupler into the
hole in the bracket.
E. Insert the projection on the recti-
fier/regulator coupler into the
hole in the bracket.
F. Position the ignition coil bracket
to the outside of the ignition coil,
and insert the bolts from the igni-
tion coil side.
G. Fasten the AC magneto lead to
the ignition coil bracket with a
plastic locking tie, making sure
to position the tie above the low-
er mounting portion of the brack-
et. Face the buckle of the plastic
locking tie forward, and then cut
off the excess end of the tie.
H. Route the ignition coil lead be-
tween the condenser and the ig-
nition coil.
I. Fit the clip portion of the clamp
into the ignition coil bracket and
fasten the clutch cable with the
locking portion of the clamp.
J. Route the clutch cable to the
outside of the AC magneto lead.
K. Route the throttle cables under
radiator hose 2, making sure not
to twist the cables.
L. Route the AC magneto lead to
the inside of the throttle cables
and clutch cable.
M. Install the ground lead terminal
between the ECU bracket and
the cable holder, making sure to
position the terminal between
the stoppers.
N. Push in the spark plug cap com-
pletely, making sure that there is
no gap between the cylinder
head cover and the cap.
O. Apply sealant to the slit and in-
ner surface of the grommet, and
then install the grommet at the
position shown.

2-23
CABLE ROUTING DIAGRAM
1. Tension pipe
2. Coolant temperature sensor
coupler
3. Front engine bracket
4. Fuel pump coupler
5. Fuel pump
6. Intake air temperature sensor
coupler
7. Radiator hose 2
8. Radiator breather hose
9. Radiator hose 1
10. Radiator hose 4
11. Radiator pipe 2
12. Radiator hose 3
13. Cylinder head breather hose
14. Frame
15. ECU (electronic control unit)
16. ECU bracket
17. Main harness
18. AC magneto lead
19. Throttle position sensor lead
20. Condenser lead
21. Coolant temperature sensor
lead
22. Ignition coil lead
23. CondenserA. Fasten the wire harness at the
positioning tape to the ECU
bracket with a plastic locking tie.
Face the buckle of the plastic
locking tie downward, and then
cut off the excess end of the tie.
B. Install the cover onto the wire
harness coupler.
C. Route the condenser lead, throt-
tle position sensor lead, coolant
temperature sensor lead, igni-
tion coil lead, and AC magneto
lead under radiator hose 2.
D. Connect the vacuum hose to the
atmospheric pressure sensor,
and then fasten the hose with
the clamp. Make sure to face the
moving part of the sensor rear-
ward.
E. After connecting the condenser
coupler, install the coupler cover
onto the coupler.
F. After connecting the throttle po-
sition sensor coupler, install the
coupler cover onto the coupler.
G. Fasten the AC magneto lead,
condenser lead, throttle position
sensor lead, coolant tempera-
ture sensor lead, and ignition
coil lead to the frame with the
plastic band, making sure to po-
sition the band between the igni-
tion coil bracket and the tension
pipe. Face the buckle of the
plastic band to the right with the
end pointing rearward.
H. Point the end of the vacuum
hose rearward.
I. Fit the bracket into the hole in
the rubber portion of the con-
denser.
J. Fasten the radiator breather
hose to the frame with the plas-
tic band, making sure to position
the band above the front engine
bracket. Face the buckle of the
plastic band outward with the
end pointing rearward.
K. After connecting the coolant
temperature sensor coupler, in-
stall the coupler cover onto the
coupler.L. Route the radiator breather hose
between the down tubes.
M. Fasten the fuel hose and fuel
pump lead with the plastic band,
making sure to position the band
between the bend in the fuel
hose protector and the end of
the protector. Point the end of
the plastic band upward.
N. Insert the projection on the joint
coupler into the hole in the
bracket, and then install the cou-
pler cover onto the coupler.
O. Route the atmospheric pressure
sensor lead, intake air pressure
sensor lead, intake air tempera-
ture sensor lead, fuel injector
lead, and fuel pump lead above
radiator hose 2. Position the
joint coupler above radiator
hose 2.
P. Route the radiator breather hose
to the inside of radiator hose 1
and the front engine bracket.
Q. Hose installation position
(1.3–3.3 mm, 0.05–0.13 in)
R. Clip installation position (0–2.0
mm, 0–0.08 in)
S. Install the washer so that it con-
tacts the bolt head.
T. Install the collar so that the
flange on the collar contacts the
ECU bracket.

3-6
ENGINE
ENGINE
CHECKING THE COOLANT LEVEL
Do not remove the radiator cap
"1", drain bolt and hoses when the
engine and radiator are hot. Scald-
ing hot fluid and steam may be
blown out under pressure, which
could cause serious injury. When
the engine has cooled, place a
thick towel over the radiator cap,
slowly rotate the cap counter-
clockwise to the detent. This pro-
cedure allows any residual
pressure to escape. When the
hissing sound has stopped, press
down on the cap while turning
counterclockwise and remove it.
Hard water or salt water is harmful
to the engine parts. You may use
distilled water, if you can't get soft
water.
1. Place the machine on a level
place, and hold it in an upright po-
sition.
2. Remove:
• Radiator cap
3. Check:
• Coolant level "a"
Coolant level low→Add coolant.
1. RadiatorCHANGING THE COOLANT
Do not remove the radiator cap
when the engine is hot.
Take care so that coolant does not
splash on painted surfaces. If it
splashes, wash it away with water.
1. Place a container under the en-
gine.
2. Remove:
• Coolant drain bolt "1"
3. Remove:
• Radiator cap
Drain the coolant completely.
4. Clean:
• Cooling system
Thoroughly flush the cooling sys-
tem with clean tap water.
5. Install:
• Copper washer
• Coolant drain bolt
6. Fill:
• Radiator
•Engine
To specified level.
• Do not mix more than one type of
ethylene glycol antifreeze con-
taining corrosion inhibitors for
aluminum engine.
• Do not use water containing im-
purities or oil.
Handling notes of coolant:
The coolant is harmful so it should be
handled with special care.
• When coolant splashes to your
eye.
Thoroughly wash your eye with
water and see your doctor.
• When coolant splashes to your
clothes.
Quickly wash it away with water
and then with soap.
• When coolant is swallowed.
Quickly make him vomit and take
him to a doctor.
7. Install:
• Radiator cap
Start the engine and warm it up
for a several minutes.
8. Check:
• Coolant level
Coolant level low→Add coolant.
CHECKING THE RADIATOR CAP
1. Inspect:
• Seal (radiator cap) "1"
• Valve and valve seat "2"
Crack/damage→Replace.
Exist fur deposits "3" →Clean or
replace.
Coolant drain bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Recommended coolant:
High quality ethylene
glycol anti-freeze con-
taining anti-corrosion
for aluminum engine
Coolant "1" and water
(soft water) "2" mixing ra-
tio:
50%/50%
Coolant capacity:
1.13 L (0.99 Imp qt, 1.19
US qt)

3-7
ENGINE
CHECKING THE RADIATOR CAP
OPENING PRESSURE
1. Attach:
• Radiator cap tester "1" and adapt-
er "2"
Apply water on the radiator cap seal.
3. Radiator cap
2. Apply the specified pressure.
3. Inspect:
• Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds →
Replace.
CHECKING THE COOLING
SYSTEM
1. Inspect:
• Coolant level
2. Attach:
• Radiator cap tester "1" and adapt-
er "2"3. Apply the specified pressure.
• Do not apply pressure more than
specified pressure.
• Radiator should be filled fully.
4. Inspect:
•Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds →
Repair.
• Radiator
• Radiator hose joint
Coolant leakage → Repair or re-
place.
• Radiator hose
Swelling → Replace.
ADJUSTING THE CLUTCH LEVER
POSITION
1. Adjust:
• Clutch lever position
Clutch lever position adjustment
steps:
a. Loosen the locknuts "1".
b. Turn the adjusting bolt "2" until the
clutch lever position "a" is in the
desiered position .
c. Tighten the locknuts.
2. Adjust:
• Clutch cable free play
Refer to "ADJUSTING THE
CLUTCH CABLE FREE PLAY".ADJUSTING THE CLUTCH CABLE
FREE PLAY
1. Check:
• Clutch lever free play "a"
Out of specification→Adjust.
2. Adjust:
• Clutch lever free play
Clutch lever free play adjustment
steps:
a. Loosen the locknuts "1".
b. Turn the adjuster "2" until free
play "a" is within the specified lim-
its.
c. Tighten the locknuts.
• Before adjustment, expose the ad-
juster by moving the boot "3" and
cap "4" away.
• Make minute adjustment on the le-
ver side using the adjuster "5".
• After adjustment, check proper op-
eration of clutch lever.
3. Install:
•Cap "1"
• Boot "2" Radiator cap tester:
YU-24460-01/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Radiator cap opening
pressure:
108–137 kPa (1.08–1.37
kg/cm
2, 15.4–19.5 psi)
Radiator cap tester:
YU-24460-01/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Standard pressure:
196 kPa (1.96 kg/cm2,
27.9 psi)
Locknut:
5 Nm (0.5 m•kg, 3.6
ft•lb)
Clutch lever free play "a"
:
7–12 mm (0.28–0.47 in)
Locknut:
4 Nm (0.4 m•kg, 2.9
ft•lb)

3-8
ENGINE
ADJUSTING THE THROTTLE
CABLE FREE PLAY
1. Check:• Throttle grip free play "a"
Out of specification →Adjust.
2. Adjust: • Throttle grip free play
Throttle grip free play adjustment
steps:
a. Slide the adjuster cover.
b. Loosen the locknut "1".
c. Turn the adjuster "2" until the specified free play is obtained.
d. Tighten the locknut.
Before adjusting the throttle cable
free play, the engine idle speed
should be adjusted.
After adjusting th e throttle cable
free play, start the engine and turn
the handlebar to right and left and
make sure that the engine idling
does not run faster.
LUBRICATING THE THROTTLE
1. Remove: • Cover (throttle cable cap) "1"
• Cover (grip cap) "2"
• Throttle grip cap "3" 2. Apply:
• Lithium soap base greaseOn the throttle cable end "a".
3. Install: • Throttle grip cap
• Screw (throttle grip cap)
• Cover (grip cap)
• Cover (throttle cable cap)
CHECKING THE THROTTLE
VALVE PULLY COVER DRAIN
HOSE
Drain the water that stays in the throt-
tle valve pulley cove r after a machine
wash or a rainy weather ride.
1. Drain the water by picking up the flat portion of the lower end "a" of
the drain hose.
CLEANING THE AIR FILTER
ELEMENT
1. Remove: •Seat
2. Remove the fuel tank bolt (front) "1" and lift the fuel tank.
Hold the fuel tank in position by the
use of the fuel tank holding cable "2".
3. Remove:• Mounting bolt for air filter case
cover 4. Loosen and release the binder "1"
and lift the air filter case lid.
Hold the air filter case lid by the use of
the binder.
5. Remove:• Air filter guide
• Air filter element "1"
Do not remove the thin sheet (air
filter element 2) "2" under the air
filter element unless it is dirty. It is
there to prevent foreign matter
from dropping in to the throttle
body. If the thin sheet must be re-
moved for cleaning, lift it carefully
to avoid loosening the dirt, and
then temporarily block the throttle
body opening with a clean, lint-free
cloth.
6. Clean: • Air filter element
Clean them with solvent.
After cleaning, remo ve the remaining
solvent by squeezing the element.
• Do not twist the element when squeezing the element.
• Leaving too much of solvent in
the element may result in poor
starting.
7. Inspect:• Air filter elementDamage → Replace.
Throttle grip free play
"a":
3–5 mm (0.12–0.20 in)
Screw (throttle grip cap): 4 Nm (0.4 m•kg, 2.9
ft•lb)

3-10
ENGINE
CHANGING THE ENGINE OIL
1. Start the engine and let it warm up for several minutes.
2. Stop the engine and place an oil pan under the drain bolt.
3. Remove: • Oil filler cap "1"
• Drain bolt (with gasket) "2"
• Drain bolt (with gasket) "3"Drain the engine oil.
4. If the oil filter is to be replaced dur- ing this oil change, remove the fol-
lowing parts and reinstall them.
Replacement steps:
a. Remove the oil filter element cov-er "1" and oil filter element "2".
b. Check the O-rings "3", if cracked or damaged, replace them with a
new one.
c. Install the oil filter element and oil filter element cover.
5. Install:• Gaskets
• Oil drain bolt (oil pan)
• Oil drain bolt (oil tank)
6. Fill: • Engine oil
7. Install: • Oil filler cap
8. Inspect:
• Engine (for oil leaks)
• Oil level CHECKING THE OIL PRESSURE
1. Check:
• Oil pressure
Checking steps:
a. Slightly loosen the oil pressure check bolt "1".
b. Start the engine and keep it idling until oil starts to seep from the oil
pressure check bolt. If no oil
comes out after one minute, turn
the engine off so it will not seize.
c. Check oil passages and oil pump
for damage or leakage.
d. Start the engine after solving the problem(s) and recheck the oil
pressure.
e. Tighten the oil pressure check bolt.
ADJUSTING THE ENGINE IDLING
SPEED
• Because the air pressure is lower at
high altitudes, the air-fuel mixture
will become richer. If the engine
idling speed is low, turn the starter
(choke) knob/idling screw a few
clicks counterclockwise to increase
the idling speed.
• Before adjusting the engine idling speed, make sure that the com-
pression pressure is within specifi-
cation and that the air filter element
is not clogged.
• Adjust the engine idling speed with
the starter (choke) knob/idling
screw pushed in completely.
1. Start the engine and warm it up until the engine oil has reached
the specified temperature.
2. Use a temperature probe tester "1" and contact it to the drain bolt
thread.
Recommended brand:
YAMALUBE
Recommended engine
oil type
SAE10W-30, SAE 10W-
40, SAE10W-50, SAE
15W-40, SAE 20W-40 or
SAE 20W-50
Recommended engine
oil grade
API service SG type or
higher, JASO standard
MA
Oil filter element cover:10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil drain bolt (oil pan): 20 Nm (2.0 m•kg, 14
ft•lb)
Oil drain bolt (oil tank): 20 Nm (2.0 m•kg, 14
ft•lb)
Oil quantity: Periodic oil change:0.95 L (0.84 Imp qt,
1.00 US qt)
With oil filter replace-
ment: 1.0 L (0.88 Imp qt, 1.06
US qt)
Total amount: 1.2 L (1.06 Imp qt, 1.27
US qt)
Oil pressure check bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil temperature: 55.0–65.0 °C
(131–149°F)

3-11
ENGINE
3. Adjust:• Engine idling speed
Adjustment steps:
a. Turn the starter knob/idle screw "1" until the specified engine idling
speed is obtained.
Using the digital tachometer, mea-
sure the engine speed with the detec-
tor "c" pinched in the high tension
cord "2" of the ignition coil.
ADJUSTING THE VALVE
CLEARANCE
• This section is intended for those who have basic knowledge and skill
concerning the servicing of Yama-
ha motorcycles (e.g., Yamaha deal-
ers, service engineers, etc.) Those
who have little knowledge and skill
concerning servicing are requested
not to undertake in spection, adjust-
ment, disassembly, or reassembly
only by reference to this manual. It
may lead to servicing trouble and
mechanical damage.
• The valve clearance should be ad- justed when the engine is cool to
the touch.
1. Remove:•Seat
Refer to "SEAT AND SIDE COV-
ERS" section in the CHAPTER 4.
•Fuel tank
Refer to "FUEL TANK" section in
the CHAPTER 6.
2. Remove:
• Spark plug
• Cylinder head coverRefer to "CAMSHAFTS" section
in the CHAPTER 4.
3. Remove: • Timing mark accessing screw "1"
• Crankshaft end accessing screw "2"
• O-ring
4. Check: • Valve clearanceOut of specification →Adjust.
Checking steps:
a. Turn the crankshaft counterclock-
wise with a wrench.
b. Align the alignment mark "a" on the rotor with the alignment mark
"b" on the crankcase cover.
Make sure that the alignment mark
"c" on the exhaust camshaft sprocket
and the alignment mark "d" on the in-
take camshaft sprocket are aligned
with the edge of the cylinder head.
c. Measure the valve clearance "e" using a feeler gauge "1".
Record the measured reading if the
clearance is incorrect.
Digital tachometer:
YU-39951-B/90890-
06760
To increase the engine idling speed →Turn the starter
(choke) knob/idling screw
counterclockwise "a".
To decrease the engine idling
speed →Turn the starter
(choke) knob/idling screw
clockwise "b".
Engine idling speed:1,900–2,100 r/min
Valve clearance (cold):Intake valve:0.10–0.15 mm
(0.0039–0.0059 in)
Exhaust valve: 0.20–0.25 mm
(0.0079–0.0098 in)

3-14
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 low.
• The brake operation is faulty.
A dangerous loss of braking per-
formance may occur if the brake
system is not properly bled.
1. Remove:
• Brake master cylinder cap
• Diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
2. Bleed:
• Brake fluid
Air bleeding steps:
a. Add proper brake fluid to the res-
ervoir.
b. Install the diaphragm. Be careful
not to spill any fluid or allow the
reservoir to overflow.
c. Connect the clear plastic tube "2"
tightly to the caliper bleed screw
"1".
A. Front
B. Rear
d. Place the other end of the tube
into a container.
e. Slowly apply the brake lever or
pedal several times.
f. Pull the lever in or push down on
the pedal. Hold the lever or pedal
in position.
g. Loosen the bleed screw and allow
the lever or pedal to travel to-
wards its limit.h. Tighten the bleed screw when the
lever or pedal limit has been
reached; then release the lever or
pedal.
i. Repeat steps (e) to (h) until of the
air bubbles have been removed
from the system.
If bleeding is difficult, it may be nec-
essary to let the brake fluid system
stabilize for a few hours. Repeat the
bleeding procedure when the tiny
bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on
the reservoir.
Check the operation of the brake
after bleeding the brake system.
3. Install:
• Protector (rear brake)
• Reservoir float (front brake)
• Diaphragm
• Brake master cylinder cap
ADJUSTING THE FRONT BRAKE
1. Check:
• Brake lever position "a"
2. Remove:
• Brake lever cover
3. Adjust:
• Brake lever position
Brake lever position adjustment
steps:
a. Loosen the locknut "1".b. Turn the adjusting bolt "2" until the
lever position "a" is within speci-
fied position.
c. Tighten the locknut.
Be sure to tighten the locknut, as it
will cause poor brake perfor-
mance.
4. Install:
• Brake lever cover
ADJUSTING THE REAR BRAKE
1. Check:
• Brake pedal height "a"
Out of specification→Adjust.
2. Adjust:
• Brake pedal height
Pedal height adjustment steps:
a. Loosen the locknut "1".
b. Turn the adjusting nut "2" until the
pedal height "a" is within specified
height.
• Adjust the pedal height between
the maximum "A" and the mini-
mum "B" as shown. (In this ad-
justment, the bolt "3" end "b"
should protrude out of the
threaded portion "4" but not be
less than 2 mm (0.08 in) "c" away
from the brake pedal "5").
• After the pedal height adjust-
ment, make sure that the rear
brake does not drag.
Bleed screw:
6 Nm (0.6 m•kg, 4.3
ft•lb)
Brake lever position "a":
Standard posi-
tionExtent of ad-
justment
95 mm (3.74 in)86–105 mm
(3.39–4.13 in)
Locknut:
5 Nm (0.5 m •kg, 3.6
ft•lb)
Brake pedal height "a":
Zero mm (Zero in)