2012 YAMAHA YFZ450 tires

6-4
6
3. Shift into first gear, and then release the
brake.
4. Open the throttle gradually and at the same time, release the clutch lever slowly.
WARNING! Opening the throttle abruptly or releasing the clutch lever too quickly
could make the ATV wheelie, which would
increase the chance of an accident, includ-
ing an overturn.
[EWB00731]
5. Once the ATV has attained adequate speed, release the throttle, and at the same time,
quickly pull in the clutch lever.
6. Shift the transmission into second gear. (Make sure not to shift the transmission into
neutral.)
7. Open the throttle part way and gradually re- lease the clutch lever.
8. Follow the same procedure when shifting to the next higher gear.EBU20650To decelerate
When slowing down or stopping, release the throt-
tle 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 engaging a lower gear. Improper use of the brakes or shifting
can cause the tires to lose traction, reducing con-
trol and increasing the possibility of an accident.
WARNING
EWB00710Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too high
could make the wheels stop rotating and lose
traction. This could cause loss of control, an
accident and injury. It could also cause engine
or drive train damage.NOTICEECB00180
Even with the transmission in the neutral po-
sition, do not coast for long periods of time
with the engine off, and do not tow the ATV
for long distances. The transmission is prop-
erly lubricated only when the engine is run-
ning. Inadequate lubrication may damage
the transmission.
U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

7-12
7
trol.
[EWB02631]

NOTICE: Do not shift gears without
releasing the throttle. Damage to the engine or
drive train may occur.
[ECB01071]
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 famil-
iar with the operation of your ATV.
When slowing down or stopping, release the throt-
tle 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 engaging
a lower gear. Improper use of the brakes or shifting
can cause the tires to lose traction, reducing con-
trol and increasing the possibility of an accident.
TURNING YOUR ATV
WARNING
EWB01771Always 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.
To achieve maximum traction on unpaved surfac-
es, the two rear wheels turn together at the same
speed. Therefore, unless the wheel on the inside
of the turn is allowed to slip or lose some traction,
the ATV will resist turning. A special turning tech-
nique must be used to allow the ATV to make turns
quickly and easily. It is essential that this skill be
learned first at low speed.
As you approach a curve, slow down and begin to
turn the handlebars in the desired direction. As you
do so, put your weight on the footrest to the outside
of the turn (opposite your desired direction) and
lean your upper body into the turn. Use the throttle
to maintain an even speed through the turn. This
maneuver will let the wheel on the inside of the turn
slip slightly, allowing the ATV to make the turn
properly.
U1PD60E0.book Page 12 Monday, June 13, 2011 2:57 PM

7-19
7CROSSING THROUGH SHALLOW WATER
WARNING
EWB01641Operating 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 care-
fully. Test your brakes after leaving the water. If neces-
sary, apply them several times to let friction dry out
the linings. Do not continue to ride your ATV with-
out verifying that you have regained proper braking
ability.
WARNING! Wet brakes may have re-
duced stopping ability, which could cause loss
of control.
[EWB02621]
U1PD60E0.book Page 19 Monday, June 13, 2011 2:57 PM

8-6
8
5*Brake hoses 
Check for cracks or other damage, and replace if
necessary. √√√√
 Replace. Every 4 years
6 *Parking brake Check operation and adjust if necessary. √√√√√
7 *Wheels 
Check runout and for damage, and replace if nec-
essary. √ √√√
8 *Tires 
Check tread depth and for damage, and replace if
necessary.
 Check air pressure and balance, and correct if
necessary. √ √√√
9 *Wheel hub bearings 
Check for looseness or damage, and replace if
necessary. √ √√√
10 *Swingarm pivots 
Check operation and for excessive play, and re-
place bearings if necessary.
 Lubricate with lithium-soap-based grease. √√√
11 *Upper and lower
arm pivots

Lubricate with lithium-soap-based grease. √√√
12 Drive chain 
Check chain slack and adjust if necessary.
 Check rear wheel alignment and correct if neces-
sary.
 Clean and lubricate. √√√√√
13 *Drive chain rollers Check for wear and replace if necessary. √√√
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 320U1PD60E0.book Page 6 Monday, June 13, 2011 2:57 PM

8-41
8
EBU26864Drive chain slack The drive chain slack should be checked before
each ride and adjusted if necessary.
To check the drive chain slack1. Place the ATV on a level surface.TIPWhen checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground.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. Place 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
U1PD60E0.book Page 41 Monday, June 13, 2011 2:57 PM

9-3
9
ly, turn the wheels a little every month in order
to prevent the tires from becoming degraded
in one spot.
8. Cover the muffler outlet with a plastic bag to prevent moisture from entering it.
9. Remove the battery and fully charge it. Store it in a cool, dry place and charge it once a
month. Do not store the battery in an exces-
sively cold or warm place [less than 0 ° C (30
° F) or more than 30 ° C (90 °F)]. For more in-
formation on storing the battery, see page
8-48.
TIPMake any necessary repairs before storing the
ATV.U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

10-3
10
Secondary reduction system:Chain drive
Secondary reduction ratio: 38/14 (2.714)
Transmission type:
Constant mesh 5-speed
Operation: Left foot operation
1st: 29/12 (2.416)
2nd:
27/14 (1.928)
3rd: 25/16 (1.562)
4th: 23/18 (1.277)
5th:
21/20 (1.050)Chassis:Frame type:Steel tube frame
Caster angle:
5.0 °
Trail: 21.0 mm (0.83 in)Front tire:Type:
Tubeless
Size: AT21 x 7-10
Manufacturer/model: DUNLOP/KT851B Bias
Rear tire:Type:Tubeless
Size:
AT20 x 10R9
Manufacturer/model: DUNLOP/KT355A RadialLoading:Maximum loading limit:
100.0 kg (220 lb)
(Total weight of rider, cargo, accessories, and tongue)Tire air pressure (measured on cold tires):Recommended:Front:
25.0 kPa (0.250 kgf/cm ², 3.6 psi)
Rear: 30.0 kPa (0.300 kgf/cm ², 4.4 psi)
Minimum: Front: 22.0 kPa (0.220 kgf/cm ², 3.2 psi)
Rear: 27.0 kPa (0.270 kgf/cm ², 4.0 psi)Front wheel:Wheel type:
Panel wheel
Rim size: 10 x 5.5ATRear wheel:Wheel type:Panel wheel
U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

Maintenance and lubrication chart ................................. 8-5
Maintenance chart, emission control system ................. 8-3
Model label ................................................................... 11-2NNeutral indicator light ..................................................... 4-2OOwner’s manual and tool kit ........................................... 8-2PPanel, removing and installing ....................................... 8-9
Parking ........................................................................... 6-5
Parking brake free play, adjusting ................................ 8-37
Parking brake lever ........................................................ 4-6
Parking on a slope ......................................................... 6-6
Part locations ................................................................. 3-1RRiding your ATV ............................................................. 7-1SSafety information .......................................................... 2-1
Seat .............................................................................. 4-12
Shifting ........................................................................... 6-3
Shift pedal ...................................................................... 4-7
Shift pedal, checking .................................................... 8-45
Shock absorber assemblies, adjusting the front .......... 4-13
Shock absorber assembly, adjusting the rear .............. 4-14
Spark arrester, cleaning ............................................... 8-28
Spark plug, checking .................................................... 8-10
Specifications ............................................................... 10-1
Speed limiter .................................................................. 4-4
Starter (choke) ............................................................. 4-11
Start switch ..................................................................... 4-3
Steering shaft, lubricating ............................................. 8-47
Storage ........................................................................... 9-2 Suspension, lubricating the upper and lower arm
pivots ......................................................................... 8-46
Swingarm pivots, lubricating ........................................ 8-46
TTail/brake light bulb, replacing ..................................... 8-53
Throttle lever ........................................................... 4-3, 5-5
Throttle lever free play, adjusting ................................. 8-31
Tires ............................................................................... 5-5
Troubleshooting ........................................................... 8-55
Troubleshooting charts ................................................. 8-57VValve clearance ............................................................ 8-31
Vehicle identification number ....................................... 11-1WWheel hub bearings, checking ..................................... 8-45
Wheel, installing ........................................................... 8-55
Wheel, removing .......................................................... 8-54
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM