2021 YAMAHA YFZ450R clutch

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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4-2
4
EBU17715Controls and instruments1. Clutch lever
2. Parking brake lever
3. Handlebar switches
4. Main switch
5. Front brake fluid reservoir
6. Throttle lever
7. Brake lever
2
1
3
6
5
4
7
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5-5
5
the adjusting screw in direction (b). Do not
turn the adjusting screw out more than 12
mm (0.47 in) or the throttle cable could be
damaged. Always make sure the throttle lever
free play is adjusted to 2.0–4.0 mm (0.08–
0.16 in). (See page 9-28.)
WARNING! Im-
proper adjustment of the speed limiter and
throttle could cause throttle cable damage
or improper throttle operation. You could
lose control, resulting in an accident.
[EWB00242]
3. Tighten the locknut.EBU18384Clutch lever
The clutch lever is located on the left side of the
handlebar. To disengage the clutch, pull the clutch
lever toward the handlebar grip. To engage the
clutch, release the lever. The lever should be
pulled rapidly and released slowly for smooth
clutch operation.
The clutch lever is equipped with a clutch switch,
which is part of the ignition circuit cut-off system.
(See page 7-1.)EBU18426Brake lever
1. Clutch lever
1. Brake lever
2. Locknut
3. Brake lever position adjusting bolt
4. Distance between brake lever and handlebar grip
1
4
23
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5-7
5
WARNING
EWB00221Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.
 Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose braking performance which could cause an
accident. You could also wear out the brakes
prematurely.
EBU18532Shift pedalThe shift pedal is located on the left side of the en-
gine and is used in combination with the clutch
when shifting. (See page 7-2.)
1. Parking brake lever (unlocked position)
1. Shift pedal
1
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6-2
6
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. 6-4, 9-29, 9-30, 9-32
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. 6-4, 9-29, 9-30, 9-32
Clutch • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 9-35
Throttle lever • Make sure that operation is smooth. Lubricate cable and lever
housing if necessary.
• Check lever free play, and adjust if necessary. 6-5, 9-28
Control cables • Make sure that operation is smooth. Lubricate if necessary. 9-38
Drive chain • Check chain slack, and adjust if necessary.
• Check chain condition. Lubricate if necessary. 6-5, 9-36, 9-38
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. 6-5
Shift pedal • Make sure that operation is smooth.
• Correct if necessary.
9-40
Brake pedal • Make sure that operation is smooth. Lubricate pedal pivoting point
if necessary. 9-40
ITEM ROUTINE PAGE
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6-3
6
Brake and clutch levers• Make sure that operation is smooth. Lubricate lever pivoting points
if necessary. 9-39
Chassis fasteners • Make sure that all nuts, bolts and screws are properly tightened. 6-7
Instruments, lights and
switches • Check operation, and correct if necessary.
6-7
ITEM
ROUTINE PAGEUBKD60E0.book Page 3 Wednesday, November 18, 2020 8:39 AM

7-1
7
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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