2019 YAMAHA YFZ450 coolant temperature

4-1
4
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 “ ”
2. Engine trouble warning light “ ”
3. Coolant temperature warning light “ ”
4. Neutral indicator light “N”
12 3 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 8-53 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.EBU29943Engine 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-diagnosis system.
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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 6-4
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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Shock absorber:Gas-hydraulic damper
Wheel travel: 250 mm (9.9 in)Rear suspension:Type:Swingarm (link suspension)
Spring: Coil spring
Shock absorber:
Gas-hydraulic damper
Wheel travel: 280 mm (11.0 in)Electrical system:System voltage:
12 V
Ignition system: TCI
Charging system: AC magnetoBattery:Model:YTZ7S
Voltage, capacity: 12 V, 6.0 AhLights:Headlight:T19L, 30.0 W/30.0 W
Brake/tail light: LED Neutral indicator light:
LED
Fuel level warning light: LED
Coolant temperature warning light:
LED
Engine trouble warning light: LED
Fuses:Main fuse:
20.0 AEBU30403Noise and vibration levels statement (for Eu-
rope)
The figures quoted are emission levels and are not
necessarily safe working levels. Whilst there is a
correlation between the emission and exposure
levels, this cannot be used reliably to determine
whether or not further precautions are required.
Factors that influence the actual level of exposure
of work-force include the characteristics of the
work room, the other sources of noise, etc. i.e. the
number of machines and other adjacent process-
es, and the length of time for which an operator is
exposed to the noise. Also the permissible expo-
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INDEX
AAccessories and loading ................................................ 6-5
Air filter element, cleaning ........................................... 8-21BBattery ......................................................................... 8-43
Brake and clutch levers, checking and lubricating ...... 8-39
Brake fluid, changing ................................................... 8-31
Brake fluid level, checking ........................................... 8-30
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ..................... 8-32
Brake light switches ..................................................... 8-34
Brake pads, checking the front and rear ..................... 8-29
Brake pedal .................................................................... 4-6
Brake pedal, checking and lubricating ........................ 8-40
Brake pedal height, checking ...................................... 8-32
Brakes .......................................................................... 8-28
Brakes, front and rear .................................................... 5-4
Brake/tail light .............................................................. 8-49CCables, checking and lubricating ................................ 8-38
Chassis fasteners .......................................................... 5-7
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-5
Clutch lever free play, adjusting .................................. 8-35
Coolant .................................................................5-4, 8-20
Coolant, changing ........................................................ 8-21
Coolant temperature warning light ................................ 4-2
Cowling and panels, removing and installing .............. 8-10
DDrive chain ..................................................................... 5-5
Drive chain, lubricating ................................................ 8-38
Drive chain slack .......................................................... 8-36EEngine break-in .............................................................. 6-4
Engine oil ....................................................................... 5-4
Engine oil and oil filter element .................................... 8-14
Engine, start ................................................................... 6-1
Engine stop switch ........................................................ 4-3
Engine trouble warning light .......................................... 4-2FFuel ......................................................................... 4-9, 5-4
Fuel level warning light .................................................. 4-2
Fuel tank cap ................................................................. 4-8
Fuse, replacing ............................................................ 8-46HHandlebar position, adjusting ...................................... 4-23
Handlebar switches ....................................................... 4-3
Headlight beam, adjusting ........................................... 8-49
Headlight bulb, replacing ............................................. 8-46IIdentification numbers ................................................. 11-1
Indicator light and warning lights ................................... 4-1
Instruments, lights and switches ................................... 5-7LLabel locations ............................................................... 1-1
Light switch ................................................................... 4-3
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