2021 YAMAHA YFZ450R tires

8-11
8Select a large, flat, unpaved area to become famil-
iar with your ATV. Make sure that this area is free
of obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain.
Set the parking brake and follow the instruction on
page 7-1 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. As you
get on the ATV, be sure not to accidentally move
the shift pedal. With the engine idling, pull the
clutch lever to disengage the clutch and shift into
1st gear, and then release the parking brake.
Open the throttle gradually, and at the same time,
release the clutch lever slowly. Once the ATV has
attained adequate speed, release the throttle lever
and at the same time, quickly pull in the clutch le-
ver and shift into 2nd gear. Open the throttle part
way and gradually release the clutch.
WARNING!
If the throttle is applied too abruptly or if the
throttle is not released during shifting, or if the
shift pedal is not released before applying the
throttle, the front wheels may lift off the
ground, resulting in a loss of directional con- trol.
[EWB02632]

NOTICE: Do not shift gears without
releasing the throttle. Damage to the engine or
drive train may occur.
[ECB01072]
Use this same procedure as you move into the
higher gears. Be sure to coordinate the use of the
throttle and shift pedal properly.
Avoid higher speeds until you are thoroughly fa-
miliar with the operation of your ATV.
When slowing down or stopping, release the
throttle and apply the brakes smoothly and evenly.
As you slow down, shift to a lower gear. Be sure
that the engine has sufficiently slowed before en-
gaging a lower gear. Improper use of the brakes or
shifting can cause the tires to lose traction, reduc-
ing control and increasing the possibility of an ac-
cident.
TURNING YOUR ATV
WARNING
EWB01772Always follow proper procedures for turning as
described in this Owner’s Manual. Practice
turning at low speeds before attempting to turn
at faster speeds. Do not turn at speeds too fast
for your skills or the conditions. ATV could go
out of control, causing a collision or overturn.
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8-18
8
As you travel across a slope, lean your body in the
uphill direction. It may be necessary to correct the
steering when riding on loose surfaces by pointing
the front wheels slightly uphill. When riding on
slopes, be sure not to make sharp turns either up
or down hill.
If your ATV does begin to tip over, gradually steer
in the downhill direction if there are no obstacles
in your path. As you regain proper balance, grad-
ually steer again in the direction you wish to travel.
CROSSING THROUGH SHALLOW WATER
WARNING
EWB01642Operating this vehicle through deep or fast-
flowing water can lead to loss of control or an
overturn. To reduce your risk of drowning or
other injuries, use care when crossing through
water. Never operate this ATV water deeper
than the depth specified in your Owner’s Man-
ual, as tires may float, increasing the risk of an
overturn. The ATV can be used to cross slow moving, shal-
low water of up to a maximum of 35 cm (14 in) in
depth. Before entering the water, choose your
path carefully. Enter where there is no sharp drop
off, and avoid rocks or other obstacles which may
be slippery or upset the ATV. Drive slowly and
carefully.
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9-6
9
5*Brake hoses • Check for cracks or other damage, and replace if
necessary. √√√√
• Replace. Every 4 years
6 *Brake fluid • Change. Every 2 years
7 *Parking brake • Check operation and adjust if necessary. √√√√√
8 *Wheels • Check runout and for damage, and replace if nec-
essary. √ √√√
9 *Tires • Check tread depth and for damage, and replace if
necessary.
• Check air pressure and balance, and correct if necessary. √ √√√
10 *Wheel hub bearings • Check for looseness or damage, and replace if
necessary. √ √√√
11 *Swingarm pivots • Check operation and for excessive play, and re-
place bearings if necessary.
• Lubricate with lithium-soap-based grease. √√√
12 *Upper and lower
arm pivots • Lubricate with lithium-soap-based grease.
√√√
13 Drive chain • Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if neces-
sary.
• Clean and lubricate. √√√√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km (mi) 320
(200) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320
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9-36
9
TIPIf the specified free play cannot be obtained as de-
scribed above or if the clutch does not operate
correctly, have a Yamaha dealer check the internal
clutch mechanism. EBU26867Drive chain slackThe drive chain slack should be checked before
each ride and adjusted if necessary.TIPWhen checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground. To check the drive chain slack1. Park the ATV on a level surface.
2. Move the ATV back and forth to locate the tightest portion of the drive chain, and then
measure the drive chain slack as shown. 3. If the drive chain slack is incorrect, adjust it as
follows.
To adjust the drive chain slack 1. Park the ATV on a level surface.
2. Loosen the rear wheel axle pinch bolts.
3. Insert a rod of a diameter of 8 mm (0.3 in) and a length of 10 cm (4 in) into one of the holes in
the drive chain tensioner as shown.
Drive chain slack: 25.0–35.0 mm (0.98–1.38 in)
1. Drive chain slack
1
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10-3
10
6. Put the frame on stands or blocks to raise all
wheels off the ground. (Alternatively, turn the
wheels each month to prevent the tires from
degrading in one spot.)
7. Cover the muffler outlet with a plastic bag to prevent moisture from entering it.
8. Remove the battery and fully charge it. (See page 9-43.)
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11-3
11
Drivetrain:Primary reduction ratio:2.652 (61/23)
Secondary reduction ratio:
2.714 (38/14)
Final drive: Chain
Clutch type: Wet, multiple-disc
Transmission type:
5-speed
Gear ratio: 1st:
2.500 (35/14)
2nd: 2.000 (30/15)
3rd: 1.632 (31/19)
4th:
1.333 (28/21)
5th: 1.095 (23/21)Front tire:Size:
AT21 x 7R10
Manufacturer/model: MAXXIS/MS21Rear tire:Size:
AT20 x 10R9
Manufacturer/model: MAXXIS/MS22
Tire air pressure (measured on cold tires):Vehicle load:0.0–100.0 kg (0–220 lb)
Recommended:
Front: 35.0 kPa (0.350 kgf/cm², 5.0 psi)
Rear:
35.0 kPa (0.350 kgf/cm², 5.0 psi)
Minimum: Front:
32.0 kPa (0.320 kgf/cm², 4.6 psi)
Rear: 32.0 kPa (0.320 kgf/cm², 4.6 psi)Front wheel:Rim size:
10 X 5.5ATRear wheel:Rim size:9 X 8.0ATFront brake:Type:Hydraulic disc brakeRear brake:Type:
Hydraulic disc brakeBrake fluid:Specified brake fluid:DOT 4Front suspension:Type:Double wishbone
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12-2
12
MMain switch .................................................................... 5-1
Maintenance and lubrication chart ................................9-5
Maintenance chart, emission control system ................ 9-3
Model label ..................................................................... 1-1NNeutral indicator light .....................................................5-1OOwner’s Manual and tool kit .......................................... 9-2PParking ........................................................................... 7-4
Parking brake free play, adjusting ............................... 9-33
Parking brake lever ........................................................ 5-6
Parking on a slope ......................................................... 7-5
Part locations ................................................................. 4-1RRiding your ATV ............................................................. 8-1SSafety information .......................................................... 3-1
Seat .............................................................................. 5-10
Shifting ........................................................................... 7-2
Shift pedal ...................................................................... 5-7
Shift pedal, checking ...................................................9-40
Shock absorber, rear ...................................................5-15
Shock absorbers, front ................................................ 5-11
Spark arrester, cleaning ............................................... 9-26
Spark plug, checking ...................................................9-13
Specifications ............................................................... 11-1
Speed limiter .................................................................. 5-4
Start switch .................................................................... 5-3
Steering shaft, lubricating ............................................ 9-42Storage ........................................................................ 10-2
Suspension, lubricating
the upper and lower arm
pivots ......................................................................... 9-41
Swingarm pivots, lubricating ....................................... 9-41
TThrottle lever .......................................................... 5-4, 6-5
Throttle lever free play, adjusting ................................. 9-28
Tires ............................................................................... 6-5
Troubleshooting ........................................................... 9-50
Troubleshooting charts ................................................ 9-52VValve clearance ............................................................ 9-28
Vehicle identification number ......................................... 1-1WWheel hub bearings, checking ..................................... 9-40
Wheel, installing ........................................................... 9-50
Wheel, removing .......................................................... 9-49YYamalube ..................................................................... 9-20
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