2016 YAMAHA YZ450F stop start

1
GENERAL INFORMATION
LOCATION OF IMPORTANT LABELS............................................................ 1-1
DESCRIPTION.................................................................................................. 1-4
IDENTIFICATION............................................................................................. 1-5
VEHICLE IDENTIFICATION NUMBER ...................................................... 1-5
ENGINE SERIAL NUMBER ....................................................................... 1-5
INCLUDED PARTS.......................................................................................... 1-6
SIDESTAND ............................................................................................... 1-6
SPARK PLUG WRENCH ........................................................................... 1-6
NIPPLE WRENCH...................................................................................... 1-6
HANDLEBAR PROTECTOR ...................................................................... 1-6
FUEL HOSE JOINT COVER ...................................................................... 1-6
COUPLER FOR CONNECTING OPTIONAL PART................................... 1-6
IMPORTANT INFORMATION.......................................................................... 1-8
PREPARATION FOR REMOVAL AND DISASSEMBLY............................ 1-8
REPLACEMENT PARTS............................................................................ 1-8
GASKETS, OIL SEALS AND O-RINGS ..................................................... 1-9
LOCK WASHERS/PLATES AND COTTER PINS ...................................... 1-9
BEARINGS AND OIL SEALS ..................................................................... 1-9
CIRCLIPS ................................................................................................... 1-9
BASIC SERVICE INFORMATION.................................................................. 1-10
ELECTRICAL SYSTEM............................................................................ 1-10
SPECIAL TOOLS........................................................................................... 1-13
CONTROL FUNCTIONS................................................................................ 1-18
ENGINE STOP SWITCH .......................................................................... 1-18
LAUNCH CONTROL SWITCH ................................................................. 1-18
CLUTCH LEVER...................................................................................... 1-18
SHIFT PEDAL .......................................................................................... 1-18
KICKSTARTER LEVER............................................................................ 1-19
THROTTLE GRIP ..................................................................................... 1-19
FRONT BRAKE LEVER ........................................................................... 1-19
REAR BRAKE PEDAL.............................................................................. 1-19
STARTER KNOB/IDLE SCREW .............................................................. 1-19
FUEL TANK CAP ..................................................................................... 1-20

DESCRIPTION
1-4
EASB111009
DESCRIPTION
TIP
Designs and specifications of the vehicle are subject to change without notice. Therefore, please
note that the descriptions in this manual may be different from those for the vehicle you have pur-
chased.1. Clutch lever 10. Radiator
2. Front brake lever 11. Coolant drain bolt
3. Throttle grip 12. Rear brake pedal
4. Radiator cap 13. Air filter
5. Fuel tank cap 14. Drive chain
6. Launch control switch 15. Shift pedal
7. Engine stop switch 16. Oil level check window
8. Fuel tank 17. Starter knob/idle screw
9. Kickstarter lever 18. Front fork
2 1
7
6
89 1054 3
12 11 18 17 16 15 1413

CONTROL FUNCTIONS
1-18
EASB111029
CONTROL FUNCTIONS
EASB111030ENGINE STOP SWITCH
The engine stop switch “1” is located on the left
handlebar. Continue pushing the engine stop
switch till the engine comes to a stop.
EASB111031LAUNCH CONTROL SWITCH
The launch control switch “1” is located on top
of the left handlebar.
When the launch control switch is pressed, the
ignition timing is delayed to reduce slipping at
the rear wheel which occurs when the vehicle
accelerates from a stationary position.
This can be used to starting off in a stable man-
ner on a slippery road surface.
However, the effect may not be adequate de-
pending on the rider’s operations and road sur-
face conditions.
How to operate
1. Put the gear into the neutral position.
2. Start the engine.
3. Push the launch control switch for more than
one second to turn on the launch control
switch.
TIP
When the launch control switch is turned on, in-
dicator “2” will flash.
4. Put the gear into the 1st or 2nd gear for start-
ing off.
5. After starting off, the launch control switch
will turn off automatically when the gear is
shifted into the 3rd gear.
The launch control switch will also turn off when
the engine is stopped or the gear is shifted into
the 3rd gear or higher.
TIP
When the launch control switch is turned off, in-
dicator will stop flashing.
EASB111032CLUTCH LEVER
The clutch lever “1” is located on the left han-
dlebar. The clutch lever disengages or engag-
es the clutch.
Pull the clutch lever toward the handlebar to
disengage the clutch, and release the lever to
engage the clutch.
EASB111033SHIFT PEDAL
The shift pedal “1” has adopted a method of 1
down & 4 ups (press-down & kick-ups).
Press it down for N (neutral) to 1st, and kick it
up for 2nd to 5th.
12

STARTING AND BREAK-IN
1-21
EASB111040
STARTING AND BREAK-IN
EASB111041FUEL
Always use the recommended fuel as stated
below. Also, be sure to use new gasoline the
day of a race.
ECA
NOTICE
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
TIP
Your Yamaha engine has been designed to use
premium unleaded gasoline with a pump oc-
tane number [(R+M)/2] of 91 or higher, or a re-
search octane number of 95 or higher. If
knocking (or pinging) occurs, use a gasoline of
a different brand.
EWA
WARNING
• For refueling, be sure to stop the engine
and use enough care not to spill any fuel.
Also be sure to avoid refueling close to a
fire.
• Refuel after the engine, exhaust pipe, etc.
have cooled off.
Gasohol (For USA and Canada)
There are two types of gasohol: gasohol con-
taining ethanol and that containing methanol.
Gasohol containing ethanol can be used if the
ethanol content does not exceed 10%. Gasohol
containing methanol is not recommended by
Yamaha because it can cause damage to the
fuel system or vehicle performance problems.
EASB111042STARTING A COLD ENGINE
1. Press the shift pedal to neutral.
2. Pull the starter knob/idle screw “1” to its full
length.
TIP
When the ambient temperature is 15°C (59°F)
or below, use the starter knob/idle screw.
3. Push down the kickstarter lever lightly until
resistance is felt.
4. Fully close the throttle, and push down the
kickstarter lever in a stroke.
5. Immediately release the kickstarter lever.
EWA
WARNING
Do not open the throttle at the moment
when you kick the kickstarter lever, be-
cause this may kick back
TIP
If it fails to start, fully open the throttle grip and
give 10 to 20 slow kicks to clear the engine of
the rich air-fuel mixture retained in it.
6. When the engine starts running, warm this
up one or two minutes at a steady speed (of
3000 to 5000 r/min), and then return the
starter knob/idle screw to its original posi-
tion.
EWA
WARNING
Since exhaust gas contains harmful ingre-
dients, do not start or warm it up at an ill-
ventilated place or a closed narrow place. Recommended fuel
Premium unleaded gasoline
only
Fuel tank capacity
7.5 L (1.98 US gal, 1.65 Imp.gal)
1

STARTING AND BREAK-IN
1-22
7. To stop the engine, push the engine stop
switch “1”.
TIP
Continue pushing the engine stop switch till the
engine comes to a full stop.
EASB111043STARTING A WARM ENGINE
When the engine is warm, give a kick with the
throttle closed without using the starter knob/
idle screw.
TIP
If it fails to start, fully open the throttle grip and
give 10 to 20 slow kicks to clear the engine of
the rich air-fuel mixture retained in it.
EASB111044BREAK-IN PROCEDURES
A break-in is important so that rotating portion,
sliding surfaces, and mounted areas may fit
one another, and that the rider may become ac-
customed to the machine.
ECA
NOTICE
Before running, do maintenance on the air
filter element.
Refer to “CLEANING THE AIR FILTER ELE-
MENT” on page 3-12.
1. After warming up the engine, drive it for
about 20 minutes at a throttle opening of 1/2
or less.
2. Make a pit stop, and check mounted areas
for looseness, oil leaks, or other problems.
3. Then, drive it for about 40 minutes at a throt-
tle opening of 3/4 or less.
4. Make a pit stop again, and thoroughly check
mounted areas for looseness, oil leaks, or
other problems. Thorough checks and ad-
justments are required in particular for
stretch of cables, free play of the brake,
stretch of the drive chain, looseness of the
spoke, and so on.
ECA
NOTICE
After a break-in or after each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-24.)
Also when the following parts are replaced,
a break-in is required.
• Cylinder and Crankshaft: A break-in is re-
quired for about an hour.
• Piston, Piston ring, Valve, Camshaft, and
Gear: A break-in is required for about 30
minutes at a throttle opening of 1/2 or less.
Observe the condition of the engine careful-
ly during a break-in.
For checkpoints for a break-in, see “MAIN-
TENANCE AFTER BREAK-IN”. If any prob-
lem is found, immediately stop the engine
and make a checkup.

CLEANING AND STORAGE
1-26
EASB111048
CLEANING AND STORAGE
EASB111049CLEANING
Frequent cleaning of your vehicle will enhance
its appearance, maintain performance, and ex-
tend the life of parts.
1. Before cleaning, block the silencer outlet to
prevent water from entering. A plastic bag
secured with a rubber band may be used for
this purpose.
2. If the engine is contaminated with oil, apply
some degreaser to it with a brush. Do not
apply degreaser to the drive chain, the
sprockets, or the wheel axles.
3. Hose off dirt. Use only enough water pres-
sure to do the job.
ECA
NOTICE
Do not use high-pressure washers or steam
cleaners. Otherwise, these may cause a fail-
ure because of the entry of water.
4. After hosing off the dirt, wash all surfaces
with a mild detergent and warm water. Use
a toothbrush to clean hard-to-reach places.
5. Rinse the detergent with clean water, and
dry the surfaces with a soft towel or a cloth.
6. Immediately after cleaning, remove any wa-
ter from the drive chain with a paper towel,
and lubricate it to prevent rust.
7. Clean the seat with a vinyl upholstery clean-
er to keep the cover pliable and glossy.
8. Automotive wax may be applied to all paint-
ed or chromed surfaces. Avoid using such
wax as contains abrasives, because it may
scratch surfaces.
9. After completing the above, start the engine
and allow it to warm up for several minutes.
EASB111050STORAGE
If your vehicle is to be stored for 60 days or
more, some preventive measures must be tak-
en to avoid deterioration. After cleaning the ve-
hicle thoroughly, prepare it for storage as
follows:
1. Fill the fuel tank with gasoline.
2. Remove the spark plug, pour a spoonful of
engine oil (SAE 10W-40) into the spark plug
hole, and reinstall the plug. With the engine
stop switch pushed in, by pushing down the
kickstarter lever, crank the engine to coat
the cylinder walls with oil.3. Remove the drive chain, clean it thoroughly
with solvent, and lubricate it Reinstall the
drive chain or store it in a plastic bag tied to
the frame.
4. Lubricate all cables.
5. Lift up the frame of the vehicle to keep the
wheels off the ground.
6. Tie a plastic bag over the muffler outlet to
prevent moisture from entering.
7. If the vehicle is to be stored in a place that is
humid or exposed to the sea breeze, apply a
light coat of oil to metal surfaces. Do not ap-
ply oil to the seat or rubber parts.
TIP
Make any necessary repairs before the vehicle
is stored.

CABLE ROUTING DIAGRAM
2-32
1. Clutch cable
2. Throttle cable (return)
3. Throttle cable (pull)
4. Launch control switch lead
5. Engine stop switch lead
6. Cable holder
7. Coupler for connecting optional part
8. Engine stop switch coupler
9. Launch control switch coupler
10. Rectifier/regulator coupler
11. AC magneto lead
12. Starter knob/idle screw
13. Neutral switch lead
14. Crankcase cover
15. Front engine bracket
16. Radiator hose
17. Neutral switch coupler
18. AC magneto coupler
19. Tension arm
20. Rectifier/regulator lead
21. Main harness
22. Tank rail
23. Radiator
24. Cylinder head breather hose
25. Radiator breather hose
26. Down tube
27. Crankcase
A. Pass the engine stop switch lead and the launch
control switch lead between the frame and the ca-
ble holder. Route the launch control switch lead
above the engine stop switch lead.
B. Insert the coupler for connecting optional part into
the connector, and fix it to the bracket.
C. Insert and fix the engine stop switch coupler to
the bracket.
D. Make sure that the launch control switch lead
does not contact the radiator.
E. Insert and fix the launch control switch coupler to
the bracket.
F. Insert and fix the rectifier/regulator coupler to the
bracket.
G. Pass the AC magneto lead to the front of the ve-
hicle beyond the starter knob/idle screw and to
the rear of the vehicle beyond the radiator. No
pinch is allowed between the radiator and the
tension arm.
H. 70 mm (2.76 in)
I. Bring the neutral switch lead into line with the
crankcase cover with no sag allowed.
J. Bring the AC magneto lead into line with the
clutch cable with no sag allowed.
K. Pass the neutral switch lead to the inside of the
front engine bracket (the side of the vehicle).
L. Clamp the clutch cable and the AC magneto lead
by the plastic locking tie. Regardless of the orien-
tation of the lock on the plastic locking tie, cut the
end.
M. Pass the clutch cable with no downward sag al-
lowed.
N. Bring the grommet of the clutch cable into contact
with the radiator hose, and pass it to the outside
of the neutral switch lead and the AC magneto
lead (the outside of the vehicle).
O. 40 mm (1.57 in)
P. Clamp the clutch cable, the AC magneto lead,
and the neutral switch lead by the plastic locking
tie. Make sure that they are clamped at the posi-
tioning tape in the clutch cable. Make the lock on
the plastic locking tie face the front of the vehicle,
and cut the end.Q. After connecting the neutral switch coupler, at-
tach the coupler cover.
R. After connecting the AC magneto coupler, attach
the coupler cover.
S. Pass the rectifier/regulator lead to the inside of
the tension arm (the side of the vehicle).
T. Pass the main harness to the front of the radiator
hose (the front of the vehicle), and to the inside of
the throttle cable (the side of the vehicle).
U. Pass the engine stop switch lead and launch con-
trol switch lead between the coupler for connect-
ing optional part and the tank rail.
V. Pass the radiator breather hose between the
down tubes.
W. Clamp the radiator breather hose, above the en-
gine bracket (front). Clamp the lock on the plastic
tie with it located outside the vehicle, and face the
end toward the front of the vehicle.
X. Clamp the clutch cable at the front of the lead (the
front of the vehicle).
Y. Make the lock on the plastic locking tie face the
front of the vehicle, and insert the projection into
the hole in the frame. Cut the end of the plastic
locking tie.

ENGINE
3-8
EASB111068
ENGINE
EASB111069CHECKING THE COOLANT LEVELEWA1DX1003
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Stand the vehicle upright on a level surface.
2. Remove:
• Radiator cap “1”
3. Check:
• Coolant level
Maximum level “a” or below  Add coolant
up to the maximum level.
ECA1DX1004
NOTICE
• Adding water instead of coolant lowers the
antifreeze content. If, therefore, water is
used instead of coolant, check, and if nec-
essary, adjust the antifreeze concentra-
tion.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
4. Start the engine, warm this up for several
minutes, and then stop it.
5. Check:
• Coolant level
TIP
Before checking the coolant level, wait a few
minutes until the coolant has settled.
EASB111070CHECKING THE COOLING SYSTEM
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
2. Check:
• Radiator
• Radiator hoses
Crack/damage  Replace.
Refer to “RADIATOR” on page 6-1.
3. Install:
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EASB111071CHANGING THE COOLANTEWA1DX1004
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Place a container under the engine.
2. Remove:
• Coolant drain bolt “1”
3. Remove:
• Radiator cap
Slowly loosen the radiator cap to drain cool-
ant.
TIP
When the radiator cap is loosened, coolant will
gush out transversely; therefore, bring the con-
tainer near to the outlet.
4. Thoroughly flush the cooling system with
clean tap water.
1. Radiator
1