2021 YAMAHA YFZ450R key

EBU17331
IMPORTANT MANUAL INFORMATION
EBU17344FAILURE TO FOLLOW THE WARNINGS CONTAINED IN THIS MANUAL CAN RESULT IN SERIOUS IN-
JURY OR DEATH.
Particularly important information is distinguished in this manual by the following notations:TIPProduct and specifications are subject to change without notice.
 The ATV you have purchased may differ slightly from the figures shown in this manual.
This is the safety alert symbol. It is used to alert you to potential per-
sonal injury hazards. Obey all safety messages that follow this sym-
bol to avoid possible injury or death.
A WARNING indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
A NOTICE indicates special precautions that must be taken to avoid
damage to the vehicle or other property.
A TIP provides key information to make procedures easier or clearer.
WARNING
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EBU17739
INSTRUMENT AND CONTROL FUNCTIONS
EBU29913Main switch“” (on)
All electrical systems are supplied with power. The
engine can be started. The key cannot be re-
moved.
“ ” (off)
All electrical systems are off. The key can be re-
moved.
EBU29383Indicator light and warning lightsEBU17861Neutral indicator light “ ”
This indicator light comes on when the transmis-
sion is in the neutral position.
1. Main switch
OFF
ON
1
1. Fuel level warning light Ž
2. Engine trouble warning light Ž
3. Coolant temperature warning light Ž
4.
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EBU29924Coolant temperature warning light “ ”
This warning light comes on when the engine
overheats. When this occurs, stop the engine as
soon as it is safe to do so and allow it to cool for
10 minutes.
The electrical circuit of the warning light can be
checked by turning the key to “ ” (on). The
warning light should come on for a few seconds,
and then go off.
If the warning light does not come on initially when
the key is turned to “ ” (on), or if the warning
light remains on, have a Yamaha dealer check the
vehicle.TIPThe radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.
 If the engine overheats, see page 9-53 for fur-
ther instructions. NOTICEECB00011The engine may overheat if the ATV is over-
loaded. In this case, reduce the load to spec-
ification. 
Start the engine after making sure that the
warning light is out. Continuous use while
the warning light is on may cause damage to
the engine.
EBU29933Fuel level warning light “ ”
This warning light comes on when the fuel level
drops below approximately 3.4 L (0.90 US gal,
0.75 Imp.gal). When this occurs, refuel as soon as
possible.
The electrical circuit of the warning light can be
checked by setting the engine stop switch to “ ”
and turning the key to “ ” (on). The warning light
should come on for a few seconds, and then go
off.
If the warning light does not come on initially when
the key is turned to “ ” (on), or if the warning
light remains on, have a Yamaha dealer check the
electrical circuit.EBU29944Engine trouble warning light “ ”
This warning light comes on or flashes when an
electrical circuit monitoring the engine is not work-
ing correctly. When this occurs, have a Yamaha
dealer check the self-diagnostic system.
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The electrical circuit of the warning light can be
checked by turning the key to “ ” (on). The
warning light should come on for a few seconds,
and then go off.
If the warning light does not come on initially when
the key is turned to “ ” (on), or if the warning
light remains on, have a Yamaha dealer check the
electrical circuit.
EBU18068Handlebar switches
EBU18081Engine stop switch “ / ”
Set this switch to “ ” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this
switch to stop the engine in an emergency situa-
tion. The engine will not start or run when this
switch is set to “ ”.EBU18102Start switch “ ”
Push this switch to crank the engine with the start-
er. See the starting instructions on page 7-1 prior
to starting the engine.EBU18157Light switch “ / /OFF”
Set this switch to “ ” to turn on the low beams
and the taillight. Set the switch to “ ” to turn on
the high beams and the taillight. Set the switch to
“OFF” to turn off all the lights.NOTICEECB00046Do not use the headlights with the engine
turned off for an extended period of time. The
battery may discharge to the point that the
1. Light switch “ / /OFF”
2. Engine stop switch “ / ”
3. Start switch “ ”
1
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EBU19882
OPERATION
EBU19902Read the Owner’s Manual carefully before riding
the ATV. If there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWB00632Read the Owner’s Manual carefully to become
familiar with all controls in order to help pre-
vent any loss of control, which could cause an
accident or injury. EBU29954Starting the engineNOTICEECB00151See the “Engine break-in” section on page 7-4
prior to operating the engine for the first time. 1. Set the parking brake.
2. Turn the key to “ ” (on) and the engine stopswitch to “ ”.
The following warning lights should come on
for a few seconds, then go off. 
Coolant temperature warning light
 Fuel level warning light
 Engine trouble warning light
NOTICEECB00826To avoid possible damage, do not operate the
ATV if a warning light does not work as de-
scribed above. 3. Shift the transmission into neutral. The neutral
indicator light should come on, if it does not
come on, have a Yamaha dealer check the
electrical circuit.TIPThis model is equipped with an ignition circuit cut-
off system. The engine can be started under the
following conditions.
The transmission is in neutral.
 The clutch is disengaged with the transmission
in gear. However, it is recommended to shift
into neutral before starting the engine. 4. Completely close the throttle lever and start
the engine by pushing the start switch.
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EBU29963Replacing the fuseThe fuse holder is located under the seat. (See
page 5-10.)
If the fuse is blown, replace it as follows.1. Turn the key to “ ” (off) and turn off all elec- trical circuits.NOTICEECB00641To prevent accidental short-circuiting, turn off
the main switch when checking or replacing a
fuse.
2. Remove the blown fuse, and then install anew fuse of the specified amperage.
WARNING! Always use a fuse of the spec- ified rating, and never use a substitute ob-
ject in place of the proper fuse. An
improper fuse or a substitute object can
cause damage to the electrical system,
which could lead to a fire.
[EWB02173]
3. Turn the key to “ ” (on) and turn on the elec- trical circuits to check if the devices operate.
4. If the fuse immediately blows again, have a Yamaha dealer check the electrical system.EBU30873Replacing a headlight bulbIf a headlight bulb burns out, replace it with the
specified bulb as follows.1. Remove the headlight unit by removing the bolt and pulling the headlight unit outward as
shown.
1. Fuse
2. Spare fuse
1
2
Specified fuse:20.0 A
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