2021 YAMAHA YFZ450R oil

EBU17421
TABLE OF CONTENTS
VEHICLE IDENTIFICATION ............................ 1-1Identification numbers ................................ 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS .............................. 2-1
SAFETY INFORMATION ................................ 3-1
DESCRIPTION................................................ 4-1 Left view ...................................................... 4-1
Right view.................................................... 4-1
Controls and instruments............................ 4-2
INSTRUMENT AND CONTROL
FUNCTIONS ................................................... 5-1 Main switch ................................................. 5-1
Indicator light and warning lights ................ 5-1
Handlebar switches .................................... 5-3
Throttle lever ............................................... 5-4
Speed limiter ............................................... 5-4
Clutch lever ................................................. 5-5
Brake lever .................................................. 5-5
Brake pedal ................................................. 5-6
Parking brake lever ..................................... 5-6 Shift pedal................................................... 5-7
Fuel tank cap .............................................. 5-8
Fuel ............................................................. 5-9
Seat .......................................................... 5-10
Front shock absorbers ............................ 5-11
Rear shock absorber ................................ 5-15
Handlebar position ................................... 5-23
PRE-OPERATION CHECKS .......................... 6-1 Fuel ............................................................. 6-4
Engine oil .................................................... 6-4
Coolant ....................................................... 6-4
Front and rear brakes ................................. 6-4
Throttle lever ............................................... 6-5
Drive chain .................................................. 6-5
Tires ............................................................ 6-5
Chassis fasteners ....................................... 6-7
Instruments, lights and switches ................ 6-7
OPERATION .................................................. 7-1 Starting the engine ..................................... 7-1
Shifting........................................................ 7-2
Engine break-in........................................... 7-4
Parking........................................................ 7-4UBKD60E0.book Page 1 Wednesday, November 18, 2020 8:39 AM

Parking on a slope ...................................... 7-5
Accessories and loading ............................. 7-5
RIDING YOUR ATV ........................................ 8-1 GETTING TO KNOW YOUR ATV ................ 8-2
RIDE WITH CARE AND GOOD JUDGMENT .............................................. 8-2
BE CAREFUL WHERE YOU RIDE ............... 8-8
TURNING YOUR ATV................................ 8-11
CLIMBING UPHILL ................................... 8-13
RIDING DOWNHILL .................................. 8-16
CROSSING A SLOPE................................ 8-17
CROSSING THROUGH SHALLOW WATER .................................................... 8-18
RIDING OVER ROUGH TERRAIN ............. 8-20
SLIDING AND SKIDDING.......................... 8-20
WHAT TO DO IF... ..................................... 8-21
PERIODIC MAINTENANCE AND
ADJUSTMENT................................................ 9-1 Owner’s Manual and tool kit ....................... 9-2
Periodic maintenance chart: Emission control system .......................................... 9-3
Periodic maintenance chart: General maintenance and lubrication..................... 9-5
Removing and installing the cowling and panels...................................................... 9-10 Checking the spark plug........................... 9-13
Engine oil and oil filter element................. 9-14
Why Yamalube ......................................... 9-20
Coolant ..................................................... 9-20
Cleaning the air filter element ................... 9-22
Cleaning the spark arrester ...................... 9-26
Adjusting the throttle lever free play ......... 9-28
Valve clearance......................................... 9-28
Brakes....................................................... 9-28
Checking the front and rear brake pads... 9-29
Checking the brake fluid level .................. 9-30
Changing the brake fluid .......................... 9-31
Checking the front brake lever free play... 9-32
Checking the brake pedal height.............. 9-32
Adjusting the parking brake free play ....... 9-33
Brake light switches ................................. 9-34
Adjusting the clutch lever free play .......... 9-35
Drive chain slack....................................... 9-36
Lubricating the drive chain ....................... 9-38
Checking and lubricating the cables ........ 9-38
Checking and lubricating the brake and
clutch levers ........................................... 9-39
Checking the shift pedal ........................... 9-40
Checking and lubricating the brake pedal ....................................................... 9-40
Checking the wheel hub bearings ............ 9-40
Lubricating the swingarm pivots .............. 9-41
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3-5
3
4. Once immediate safety hazards are con-
firmed not to exist, you may remove your hel-
met to more closely inspect your vehicle.
Check for external signs of wear, broken
parts, fluid leaks, cracks in the frame, sus-
pension damage, wheel damage, and so on.
Fuel, oil, and coolant usually give off a notice-
able odor.
5. If your vehicle will not restart or if it is unsafe to ride, then turn off all vehicle systems (en-
gine stop switch, main switch, and fuel cock),
and then signal or go for help.
Aftermarket Parts, Accessories, and Modifica-
tions
While you may find aftermarket products similar in
design and quality to genuine Yamaha accesso-
ries, recognize that some aftermarket accessories
or modifications are not suitable because of po-
tential safety hazards to you or others. Installing
aftermarket products or having other modifica-
tions performed to your vehicle that change any of
the vehicle’s design or operation characteristics
can put you and others at greater risk of serious
injury or death. You are responsible for injuries re-
lated to changes in the vehicle. Keep the following guidelines in mind, as well as those found in the
Loading section (page 7-6) when mounting acces-
sories.

Never install accessories that would impair the
performance of your ATV. Carefully inspect the
accessory before using it to make sure that it
does not in any way reduce ground clearance,
limit suspension travel, steering travel or control
operation.
 Accessories fitted to the ATV can create insta-
bility due to improper weight distribution.
 Bulky or large accessories may seriously affect
the stability of the ATV.
 Certain accessories can displace the operator
from his or her normal riding position. This im-
proper position limits the freedom of movement
of the operator and may limit control ability,
therefore, such accessories are not recom-
mended.
 Use caution when adding electrical accesso-
ries. If electrical accessories exceed the capac-
ity of the ATV’s electrical system, an electric
failure could result, which could cause a dan-
gerous loss of lights or engine power. Also, the
battery tends to discharge more quickly if elec-
trical accessories are added.
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4-1
4
EBU17681
DESCRIPTION
EBU17691Left view
EBU17701Right view
1. Front shock absorber
2. Engine oil tank filler cap
3. Rear brake fluid reservoir
4. Battery
5. Shift pedal
6. Coolant reservoir
563
1
4
2
1. Spark arrester
2. Fuse
3. Fuel tank cap
4. Oil filter element
5. Brake pedal
6. Rear brake light switch
7. Rear shock absorber
456
2
1
7
3
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5-11
5
To install the seat
Insert the projections on the front of the seat into
the seat holders, and then push down on the seat
at the rear to lock it in place. Make sure that the
seat is securely fitted.
EBU30055Front shock absorbers The shock absorber spring preload, rebound
damping force, and compression damping force
(fast and slow compression damping) can be ad-
justed.
WARNING
EWB02492
Suspension components become hot during
operation. Never touch the compression
damping force adjusting bolt and screw, the
rebound damping force adjusting screw or
the oil reservoir with your bare hand or skin
until suspension components have cooled.
 Always adjust the shock absorber assem-
blies on the left and right side to the same
setting. Uneven adjustment can cause poor
handling and loss of stability, which could
lead to an accident. Notes on adjusting the suspension
A special wrench can be obtained at a Yamaha
dealer to make the spring preload adjustment.
 When adjusting the damping force settings, turn
the adjuster in direction (a) until it stops, and
then count the turns or clicks in direction (b).
 Although a damping force adjuster may turn or
click beyond the stated minimum settings, such
adjustments are ineffective and may damage
the suspension.
1. Projection
2. Seat holder
1
2
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5-16
5
WARNING
EWB02681Suspension components become hot during
operation. Never touch the compression
damping force adjusting bolt and screw, the
rebound damping force adjusting screw or the
oil reservoir with your bare hand or skin until
the suspension components have cooled. Notes on adjusting the suspension
A special wrench can be obtained at a Yamaha
dealer to make the spring preload adjustment.
 When adjusting the damping force settings, turn
the adjuster in direction (a) until it stops, and
then count the turns or clicks in direction (b).
 Although a damping force adjuster may turn or
click beyond the stated minimum settings, such
adjustments are ineffective and may damage
the suspension.NOTICEECB00091Never turn an adjusting mechanism beyond
the minimum and maximum settings.
Spring preload
1. Elevate the vehicle and place a suitable stand under the frame.
2. Remove the cowling. (See page 9-10.)
3. Remove the clip from the hose holder, re- move the bolt, and then move the blow-by
gas chamber away from the vehicle.
4. Loosen the clamp screw at the air filter case side.1. Hose holder
2. Clip
3. Bolt
4. Blow-by gas chamber
2 3
4
1
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6-1
6
EBU19203
PRE-OPERATION CHECKS
EBU19227Inspect 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. 5-9, 6-4
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. 6-4, 9-14
Coolant • Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.
• Check cooling system for leakage. Correct if necessary. 6-4, 9-20
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6-4
6
EBU38000FuelMake sure there is sufficient gasoline in the tank
before starting off. Refuel if necessary. (See page
5-9.)EBU19561Engine oilMake sure that the engine oil is at the specified
level. Add oil as necessary. (See page 9-14.)EBU19632CoolantMake sure that the coolant is at the specified level.
Add coolant as necessary. (See page 9-20.)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
9-32.) 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 9-30.)
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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