2011 YAMAHA YZ450F warning

FOREWORD
INTRODUCTION
Congratulations on your purchase of
a Yamaha YZ series. This model is
the culmination of Yamaha's vast ex-
perience in the production of paceset-
ting racing machines. It represents
the highest grade of craftsmanship
and reliability that have made Yama-
ha a leader.
This manual explains operation, in-
spection, basic maintenance and tun-
ing of your machine. If you have any
questions about this manual or your
machine, please contact your Yama-
ha dealer.
Yamaha continually seeks advance-
ments in product design and quality.
Therefore, while this manual contains
the most current product information
available at the time of printing, there
may be minor discrepancies between
your machine and this manual. If you
have any questions concerning this
manual, please consult your Yamaha
dealer.
PLEASE READ THIS MANUAL
CAREFULLY AND COMPLETELY
BEFORE OPERATING THIS MA-
CHINE. DO NOT ATTEMPT TO OP-
ERATE THIS MACHINE UNTIL YOU
HAVE ATTAINED A SATISFACTO-
RY KNOWLEDGE OF ITS CON-
TROLS AND OPERATING
FEATURES AND UNTIL YOU HAVE
BEEN TRAINED IN SAFE AND
PROPER RIDING TECHNIQUES.
REGULAR INSPECTIONS AND
CAREFUL MAINTENANCE,
ALONG WITH GOOD RIDING
SKILLS, WILL ENSURE THAT YOU
SAFETY ENJOY THE CAPABILI-
TIES AND THE RELIABILITY OF
THIS MACHINE.
IMPORTANT MANUAL
INFORMATION
Particularly important information is
distinguished in this manual by the
following notations.
This is the safety alert symbol. It is
used to alert you to potential per-
sonal injury hazards. Obey all safe-
ty messages that follow this
symbol to avoid possible injury or
death.
A WARNING indicates a hazardous
situation which, if not avoided,
could result in death or serious in-
jury.
A NOTICE indicates special pre-
cautions that must be taken to
avoid damage to the vehicle or oth-
er property.
A TIP provides key information to
make procedures easier or clearer.
SAFETY INFORMATION
THIS MACHINE IS DESIGNED
STRICTLY FOR COMPETITION
USE, ONLY ON A CLOSED
COURSE. It is illegal for this machine
to be operated on any public street,
road, or highway. Off-road use on
public lands may also be illegal.
Please check local regulations before
riding.
• THIS MACHINE IS TO BE OPER-
ATED BY AN EXPERIENCED RID-
ER ONLY.
Do not attempt to operate this ma-
chine at maximum power until you
are totally familiar with its character-
istics.
• THIS MACHINE IS DESIGNED TO
BE RIDDEN BY THE OPERATOR
ONLY.
Do not carry passengers on this
machine.
• ALWAYS WEAR PROTECTIVE
APPAREL.
When operating this machine, al-
ways wear an approved helmet with
goggles or a face shield. Also wear
heavy boots, gloves, and protective
clothing. Always wear proper fitting
clothing that will not be caught in
any of the moving parts or controls
of the machine.• ALWAYS MAINTAIN YOUR MA-
CHINE IN PROPER WORKING
ORDER.
For safety and reliability, the ma-
chine must be properly maintained.
Always perform the pre-operation
checks indicated in this manual.
Correcting a mechanical problem
before you ride may prevent an ac-
cident.
• GASOLINE IS HIGHLY FLAMMA-
BLE.
Always turn off the engine while re-
fueling. Take care to not spill any
gasoline on the engine or exhaust
system. Never refuel in the vicinity
of an open flame, or while smoking.
• GASOLINE CAN CAUSE INJURY.
If you should swallow some gaso-
line, inhale excess gasoline vapors,
or allow any gasoline to get into
your eyes, contact a doctor immedi-
ately. If any gasoline spills onto
your skin or clothing, immediately
wash skin areas with soap and wa-
ter, and change your clothes.
• ONLY OPERATE THE MACHINE
IN AN AREA WITH ADEQUATE
VENTILATION.
Never start the engine or let it run
for any length of time in an enclosed
area. Exhaust fumes are poison-
ous. These fumes contain carbon
monoxide, which by itself is odor-
less and colorless. Carbon monox-
ide is a dangerous gas which can
cause unconsciousness or can be
lethal.
• PARK THE MACHINE CAREFUL-
LY; TURN OFF THE ENGINE.
Always turn off the engine if you are
going to leave the machine. Do not
park the machine on a slope or soft
ground as it may fall over.
• THE ENGINE, EXHAUST PIPE,
MUFFLER, AND OIL TANK WILL
BE VERY HOT AFTER THE EN-
GINE HAS BEEN RUN.
Be careful not to touch them or to
allow any clothing item to contact
them during inspection or repair.
• PROPERLY SECURE THE MA-
CHINE BEFORE TRANSPORTING
IT.
For safety, drain the gasoline from
the fuel tank before transporting the
vehicle.

3-21
CHASSIS
CHECKING THE TIRE PRESSURE
1. Measure:
• Tire pressure
Out of specification→Adjust.
• Check the tire while it is cold.
• Loose bead stoppers allow the tire
to slip off its position on the rim
when the tire pressure is low.
• A tilted tire valve stem indicates that
the tire slips off its position on the
rim.
• If the tire valve stem is found tilted,
the tire is considered to be slipping
off its position. Correct the tire posi-
tion.
CHECKING AND TIGHTENING THE
SPOKES
The following procedure applies to all
of the spokes.
1. Check:
• Spokes
Bend/damage→Replace.
Loose spoke→Retighten.
Tap the spokes with a screw-
driver.
A tight spoke will emit a clear, ringing
tone; a loose spoke will sound flat.
2. Tighten:
• Spokes
(with a spoke nipple wrench "1")
Be sure to retighten these spokes be-
fore and after break-in.
CHECKING THE WHEELS
1. Inspect:
• Wheel runout
Elevate the wheel and turn it.
Abnormal runout→ Replace.
2. Inspect:
• Bearing free play
Exist play→Replace.
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Place a stand under the engine to
raise the front wheel off the
ground. WARNING! Securely
support the vehicle so that
there is no danger of it falling
over.
2. Check:
• Steering stem
Grasp the bottom of the forks and
gently rock the fork assembly
back and forth.
Free play→Adjust steering head.3. Check:
• Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action→Adjust steer-
ing ring nut.
4. Adjust:
• Steering ring nut
Steering ring nut adjustment
steps:
a. Remove the number plate.
b. Remove the handlebar and upper
bracket.
c. Loosen the steering ring nut "1"
using the steering nut wrench "2".
d. Tighten the steering ring nut "3"
using steering nut wrench "4".
• Apply the lithium soap base grease
on the thread of the steering stem.
• Set the torque wrench to the steer-
ing nut wrench so that they form a
right angle.
Standard tire pressure:
100 kPa (1.0 kgf/cm2,
15 psi)
Spoke nipple wrench:
YM-01521/90980-01521
Spokes:
3 Nm (0.3 m•kg, 2.2
ft•lb)
Steering nut wrench:
YU-33975/90890-01403
Steering nut wrench:
YU-33975/90890-01403
Steering ring nut (initial
tightening):
38 Nm (3.8 m•kg, 27
ft•lb)

7-9
FUEL INJECTION SYSTEM
FUEL INJECTION SYSTEM
TROUBLESHOOTING METHOD
Engine starting problems, engine
idling speed problems, and medium
and high-speed performance prob-
lems
1. CHECK:
• Refer to "TROUBLESHOOTING"
section in the chapter 3.
2. Connect the FI diagnostic tool.
(Refer to "CONNECTING THE FI
DIAGNOSTIC TOOL".)
3. Check the fault code number.
(Refer to "TROUBLESHOOTING
DETAILS".)
• Check the fault code number that is
displayed on the LCD of the FI diag-
nostic tool.
• Identify the system with the mal-
function.(Refer to "TROUBLE-
SHOOTING DETAILS".)
4. Checking and repair the probable
case of malfunction.
• Fault code No. YES.
Check and repair.
Refer to "TROUBLESHOOTING
DETAILS".
Refer to "SENSOR OPERATION
TABLE".
• Fault code No. NO.
Check each sensor and actuator
in the diagnostic mode.
Refer to "SETTING THE DIAG-
NOSTIC MODE".
Refer to "SENSOR OPERATION
TABLE".
If the sensors or actuators are
damaged, check and, if neces-
sary, repair or replace all faulty
parts.
If the sensors or actuators are not
damaged, check and, if neces-
sary, repair or replace the engine
inner parts.5. Perform ECU reinstatement ac-
tion.
Refer to "Reinstatement method"
of table in "TROUBLESHOOTING
DETAILS".
6. Set the switch on the FI diagnostic
tool sub-wire harness from "OFF"
to "ON", and then check whether
a fault code number is displayed
again.
If other fault code displayed, repeat
steps (2) to (5) until all fault code
number is not displayed.
7. Set the switch on the FI diagnostic
tool sub-wire harness to "OFF",
and then disconnect the FI diag-
nostic tool, FI diagnostic tool sub-
wire harness, and battery. Place
the accessory coupler in its origi-
nal position.
The malfunction history is stored
even if the switch on the FI diagnostic
tool sub-wire harness is set to "OFF".
Erase the malfunction history in the
diagnostic mode. (Refer to "DIAG-
NOSTIC CODE TABLE (Diagnostic
code No. D62)".)
CONNECTING THE FI
DIAGNOSTIC TOOL
1. Connect the following items to the
accessory coupler as shown.
• FI diagnostic tool "1"
• FI diagnostic tool sub-wire har-
ness "2"
• Battery "3"
• Because this vehicle is not
equipped with a battery, a 12 V
battery is required to use the FI di-
agnostic tool.
• Make sure that the switch on the
FI diagnostic tool sub-wire har-
ness is set to "OFF".
• The "POWER" LED (green)
comes on.
CHECKING THE FAULT CODES
1. Set the switch on the FI diagnostic
tool subwire harness to "ON".
When the switch on the FI diagnostic
tool sub-wire harness is set to "ON",
make sure that "Waiting for connec-
tion" is displayed on the LCD of the FI
diagnostic tool.
2. Check:
• Fault code number
• If a malfunction is detected in the
system, the fault code appears on
the LCD of the FI diagnostic tool
and the "WARNING" LED (orange)
comes on.
• To start the engine, set the switch
on the FI diagnostic tool sub-wire
harness to "OFF".
• When the engine is running, fault
code numbers will not be displayed
on the LCD of the FI diagnostic tool
even if a malfunction is detected in
the system. The "WARNING" LED
(orange) comes on.
3. Set the switch on the FI diagnostic
tool subwire harness to "OFF". FI diagnostic tool
YU-03182/90890-03182
FI diagnostic tool sub-
wire harness
YU-03212/90890-03212
2100 60
60

7-11
FUEL INJECTION SYSTEM
SENSOR OPERATION TABLE
Diagnos-
tic code
No.ItemActuation or
displayChecking methodActuation or LCD standard display
values
D01 Throttle angle DisplayDisplays the throttle angle. 0–125°
Check with throttle fully closed. When throttle is fully closed:15–19°
Check with throttle fully open. When throttle is fully
opened:95–101 °
D02 Atmosphere DisplayDisplays the atmospheric pres-
sure.
• Measure the atmospheric pres-
sure.0–126 kPa
Displays the atmospheric pressure
according to the elevation and
weather.
Example
0 m above sea level: Approx: 101
kPa
3000 m above sea level:Approx: 70
kPa
D03 Intake air pressure DisplayDisplays the intake air pressure.
• Check the intake manifold pres-
sure.
• Check that the intake air pres-
sure changes while the engine is
being cranked.0–126 kPa
While the engine is stopped: Dis-
plays the atmospheric pressure ac-
cording to the elevation and
weather.
Example
0 m above sea level: Approx: 101
kPa
3000 m above sea level:Approx: 70
kPa
While the engine is being cranked:
Displays the intake air pressure.
D05 Intake air temperature DisplayDisplays the intake air tempera-
ture.
• Check the temperature in the in-
take manifold.-20–100°C
Cold engine: Displayed tempera-
ture is close to the ambient temper-
ature.
Warm engine: Displayed tempera-
ture is approximately 20 °C higher
than the ambient temperature.
D06 Coolant temperature DisplayDisplays the coolant temperature.
• Check the coolant temperature.-20–150°C
Cold engine: Displayed tempera-
ture is close to the ambient temper-
ature.
Warm engine: Displayed tempera-
ture is the current coolant tempera-
ture.
D08 Lean angle sensor DisplayDisplays the lean angle sensor
output voltage.
Remove the ECU and incline it 45°
or more.0–5.0 V
1.0 V: Upright
4.0 V: Overturned
D30 Ignition coil ActuationCheck that power is supplied to
the ignition coil.
• Check that a spark is generated.
• Illuminates the engine trouble
warning light.Actuates the ignition coil for five
times every second.
The "WARNING" LED on the FI di-
agnostic tool comes on each time
the fuel injector is actuated.

7-12
FUEL INJECTION SYSTEM
D36 Injectors ActuationCheck that power is supplied to
the fuel injector.
• Check the fuel injector operation
by listening for the operating
sound or by confirming the oper-
ation visually.Actuates the injector for five times
every second.
The "WARNING" LED on the FI di-
agnostic tool comes on each time
the fuel injector is actuated.
D60EEPROM fault code
display.DisplayDisplays the abnormal portion of
the data in the EEPROM that has
been detected as a fault code No.
44.
If code numbers more than one
are detected, the display alter-
nates every two seconds to show
all the detected code numbers.
When all code numbers are
shown, the display repeats the
same process.00: No fault
01: CO adjustment valve
07: Power Tuner adjustment val-
ues 0–8 for fuel injection amount or
ignition timing
D61Malfunction history
code display.DisplayDisplays the fault code numbers
that are stored in the malfunction
history.
If code numbers more than one
are detected, the display alter-
nates every two seconds to show
all the detected code numbers.
When all code numbers are
shown, the display repeats the
same process.00: No history
12–50: History exists
• Refer to the fault code number.
D62Malfunction history
code erasureActuation
and displayDisplays the total number of mal-
functions, including the current
malfunction, that have occurred
since the history was last erased.
In addition, deletes the fault code
numbers from the history if the cor-
responding items are currently op-
erating normally.00: No history
1–15: History exists
When this diagnostic code number
is selected, fault code numbers for
previously detected malfunctions
are deleted from the history if the
corresponding items are currently
operating normally.
D64 Setting history display DisplayDisplays whether or not history ex-
ists for settings that were made us-
ing the Power Tuner.00: There is no setting history.
01: There is setting history.
02: Whether or not setting history
data exists cannot be determined
(damage to history data).
D65 Setting map erasure DisplayErases the settings that were
made using the Power Tuner.00: There are no settings that were
made using the Power Tuner.
01: There are settings that were
made using the Power Tuner.
D70Program version
numberDisplayCheck the version number of the
program.0–254 Diagnos-
tic code
No.ItemActuation or
displayChecking methodActuation or LCD standard display
values

7-26
FUEL INJECTION SYSTEM
Fault code No. 33
Symptom Ignition system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D30
FI diagnostic tool display Actuates the ignition coil for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the ignition coil is ac-
tuated.
Checking methodCheck the spark five times.
• Connect an ignition checker.
Item Item/components and probable cause Check or maintenance job Checking method
1 Check the connection and locking condition of
the ignition coil coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection→ Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 2.
2 Check the connection and locking condition of
the wire harness ECU coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection → Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 3.
3 Continuity of harness Open or short circuit → Replace.
Between Ignition coil coupler and
ECU coupler.
(Orange–Orange)Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 4.

7-27
FUEL INJECTION SYSTEM
4 Installed condition of ignition coil Check that the sensor is installed
securely and that there are no
pinched leads.Check that the ECU
is installed securely and that there
are no pinched leads.
Incorrect installation → Reinstall
or repair.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 5.
5 Defective ignition coil. (test the primary coils for
continuity)Defective → Replace.
Refer to "CHECKING THE IGNI-
TION COIL".Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 6.
6 Malfunction in ECU. Execute the diagnostic mode (di-
agnostic code No. D30).
No spark → Replace the ECU. Fault code No. 33
Symptom Ignition system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D30
FI diagnostic tool display Actuates the ignition coil for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the ignition coil is ac-
tuated.
Checking methodCheck the spark five times.
• Connect an ignition checker.
Item Item/components and probable cause Check or maintenance job Checking method

7-28
FUEL INJECTION SYSTEM
Fault code No. 39
Symptom Injection system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D36
FI diagnostic tool display Actuates the injector for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the fuel injector is ac-
tuated.
Checking method Check the operating sound of the injector five times.
Item Item/components and probable cause Check or maintenance job Checking method
1 Check the connection and locking condition of
the fuel injector coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection → Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item
2.
2 Faulty injector Defective → Replace.
Refer to "CHECKING THE FUEL
INJECTORS"Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item
3.
3 Check the connection and locking condition of
the wire harness ECU coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection → Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item
4.