2018 YAMAHA YFZ450R Owners Manual

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5
EBU19203
PRE-OPERATION CHECKS
EBU19226Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWB00482Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected
by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer. Before using this vehicle, check the following points:
ITEMROUTINE PAGE
Fuel • Check fuel level in fuel tank,
and add recommended fuel if neces-
sary.
• Check fuel line for leakage. Correct if necessary. 4-8, 5-4
Engine oil • Check oil level in engine oil tank, and add recommended oil to
specified level if necessary.
• Check ATV for oil leakage. Correct if necessary. 5-4, 8-14
Coolant • Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.
• Check cooling system for leakage. Correct if necessary. 5-4, 8-20
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Front brake• Check operation. If soft or spongy, have Yamaha dealer bleed hy-
draulic system.
• Check brake pads for wear, and replace if necessary.
• Check brake fluid level in reservoir, and add specified brake fluid to specified level if necessary.
• Check hydraulic system for leakage. Correct if necessary. 5-4, 8-28, 8-29, 8-31
Rear brake • Check operation. If soft or spongy, have Yamaha dealer bleed hy-
draulic system.
• Check brake pads for wear, and replace if necessary.
• Check brake fluid level in reservoir, and add specified brake fluid to specified level if necessary.
• Check hydraulic system for leakage. Correct if necessary. 5-4, 8-28, 8-29, 8-32
Clutch • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 8-34
Throttle lever • Make sure that operation is smooth. Lubricate cable and lever
housing if necessary.
• Check lever free play, and adjust if necessary. 5-5, 8-27
Control cables • Make sure that operation is smooth. Lubricate if necessary. 8-38
Drive chain • Check chain slack, and adjust if necessary.
• Check chain condition. Lubricate if necessary. 5-5, 8-35, 8-37
Wheels and tires • Check wheel condition, and replace if damaged.
• Check tire condition and tread depth. Replace if necessary.
• Check air pressure. Correct if necessary. 5-5
Shift pedal • Make sure that operation is smooth.
• Correct if necessary.
8-39
Brake pedal • Make sure that operation is smooth. Lubricate pedal pivoting point
if necessary. 8-39
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Brake and clutch levers• Make sure that operation is smooth. Lubricate lever pivoting points
if necessary. 8-39
Chassis fasteners • Make sure that all nuts, bolts and screws are properly tightened. 5-7
Instruments, lights and
switches • Check operation, and correct if necessary. 5-7
ITEM ROUTINE PAGE
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EBU19542FuelMake sure that there is sufficient fuel in the tank.
(See page 4-8.)EBU19561Engine oilMake sure that the engine oil is at the specified
level. Add oil as necessary. (See page 8-14.)EBU19632CoolantMake sure that the coolant is at the specified level.
Add coolant as necessary. (See page 8-20.)TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture. EBU19713Front and rear brakesBrake lever and brake pedal
Check that there is no free play in the brake le-
ver. If there is free play, have a Yamaha dealer
check the brake system. 
Check for correct brake pedal height. (See page
8-32.) If the pedal height is incorrect, have a
Yamaha dealer adjust it.
 Check the operation of the lever and pedal.
They should move smoothly and there should
be a firm feeling when the brakes are applied. If
not, have a Yamaha dealer check the brake sys-
tem.
Brake fluid level
Check the brake fluid level. Add fluid if necessary.
(See page 8-29.)
Brake fluid leakage
Check to see if any brake fluid is leaking out of the
pipe joints or brake fluid reservoirs. Apply the
brakes firmly for one minute. If there is any leak-
age, have a Yamaha dealer check the brake sys-
tem. Specified brake fluid:
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Brake operation
Test the brakes at slow speed after starting out to
make sure they are working properly. If the brakes
do not provide proper braking performance,
check the brake pads for wear. (See page 8-28.)
EBU19762Throttle leverCheck the operation of the throttle lever. It must
open smoothly and spring back to the idle position
when released. Have a Yamaha dealer correct if
necessary.EBU19771Drive chainCheck the condition of the drive chain and check
the drive chain slack. Lubricate and adjust the
drive chain as necessary. (See page 8-35.)EBU19816TiresCheck tire pressure regularly to make sure it is at
the recommended specifications. Also check for
wear and damage. Tire pressure
Use a tire pressure gauge to check and adjust tire
air pressure when the tires are cold. The tire air
pressure must be equal on both sides.
WARNING! Operation of this vehicle with im- proper tire pressure may cause severe injury or
death from loss of control or rollover. Tire
pressure below the minimum specified could
also cause the tire to dislodge from the rim un-
der severe riding conditions.
[EWB02542]
Recommended tire pressure: Front35.0 kPa (0.350 kgf/cm², 5.0 psi)
Rear 35.0 kPa (0.350 kgf/cm², 5.0 psi)
Minimum tire pressure: Front32.0 kPa (0.320 kgf/cm², 4.6 psi)
Rear 32.0 kPa (0.320 kgf/cm², 4.6 psi)
Maximum tire seating pressure: Front250 kPa (2.5 kgf/cm², 36 psi)
Rear 250 kPa (2.5 kgf/cm², 36 psi)
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5Tire pressure gauge
A low-pressure tire gauge is included as standard
equipment with your vehicle. (See page 8-2.)
When using the tire pressure gauge, make two
measurements and use the second reading as grit
in the gauge or tire valve could have caused the
first reading to be incorrect.
Tire wear
If the tire is damaged or the tire tread depth de-
creases to 3 mm (0.12 in) or less, replace the tire.
Tire information
This ATV is equipped with tubeless tires and tire
air valves. After extensive tests, only the tires list-
ed below are approved for this model by Yamaha.
WARNING
EWB02552Use of improper tires on this ATV may cause
loss of control, increasing your risk of an acci-
dent.
1. Low-pressure tire gauge
1
1. Tire wear limit
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Aftermarket tires and rims
The tires and rims that came with your ATV were
designed to match the performance capabilities
and to provide the best combination of handling,
braking, and comfort. Other tires, rims, sizes, and
combinations may not be appropriate.
EBU19841Chassis fastenersMake sure that all nuts, bolts and screws are
properly tightened.
EBU19851Instruments, lights and switchesCheck that all instruments, lights and switches are
working properly. Correct if necessary.
Front:
Manufacturer/model:MAXXIS/MS21
Size: AT21 x 7R10
Ty p e : Tu b e l e s s
Rear: Manufacturer/model:MAXXIS/MS22
Size: AT20 x 10R9
Ty p e : Tu b e l e s s
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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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