tire pressure YAMAHA YFZ450 2019 Owners Manual

1-6
1
E10E5

**.* kPa
*.** kgf/cm²
*.* psi **.* kPa
*.** kgf/cm²
*.* psi
This pictogram shows trailer Hitch Tow
weight limit. (Combined weight of the trailer
and all cargo in the trailer.)
Overloading can cause loss of control.
Loss of control can result in severe injury or
death.
EN228 fuel identification mark.
Gasoline of ethanol 10% or less can be
used. EN228 fuel identification mark.
Gasoline of ethanol 5% or less can be used.
Use unleaded gasoline only.
Measure the tire pressure when the tires are
cold. Adjust the tire pressure.
Improper tire pressure can cause loss of
control.
Loss of control can result in severe injury or
death.
This pictogram shows the loading limits
and/or maximum load capacity for this ATV.
Follow all load limits and other loading
guidelines in this manual.
Load may include the driver, passenger,
human protective gear, accessories, goods,
luggage, and all other load related items.
Make sure you do not exceed the load limits.
Overloading can cause loss of control.
Loss of control can result in severe injury or
death.
This pictogram shows trailer Hitch Tongue
weight limit. (Weight on the trailer tongue.)
Overloading can cause loss of control.
Loss of control can result in severe injury or
death.
UBW262E0.book Page 6 Tuesday, July 17, 2018 1:20 PM

2-3
2
technique described in this manual on level
ground. Avoid crossing the side of a steep hill if
possible.
 Always use proper procedures if you stall or roll
backwards when climbing a hill. To avoid stall-
ing, use the proper gear and maintain a steady
speed when climbing a hill. If you stall or roll
backwards, follow the special procedure for
braking described in this manual. Dismount on
the uphill side or to a side if pointed straight up-
hill. Turn the ATV around and remount, following
the procedure described in this manual.
 Always check for obstacles before operating in
a new area.
 Never attempt to operate over large obstacles,
such as large rocks or fallen trees. Always follow
proper procedures when operating over obsta-
cles as described in this manual.
 Always be careful when skidding or sliding.
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smooth
terrain. On extremely slippery surfaces, such as
ice, go slowly and be very cautious in order to
reduce the chance of skidding or sliding out of
control. 
Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may have
reduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.
 Always use the size and type of tires specified in
this manual.
 Always maintain proper tire pressure as de-
scribed in this manual.
 Never exceed the stated load capacity for an
ATV. Cargo should be properly distributed and
securely attached. Reduce speed and follow in-
structions in this manual for carrying cargo or
pulling a trailer. Allow greater distance for brak-
ing.
 Do not operate your ATV during darkness un-
less it is equipped with a properly functioning
headlight. Off-road riding is inherently danger-
ous and additionally, off-road trails do not have
streetlights to guide you.
 Never maintain an ATV without proper knowl-
edge. Contact an authorized ATV dealer to in-
form you on basic ATV maintenance. Certain
maintenance can only be carried out by certified
staff.
UBW262E0.book Page 3 Tuesday, April 3, 2018 10:59 AM

5-2
5
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, 8-29, 8-30, 8-32
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. 5-4, 8-29, 8-30, 8-32
Clutch • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 8-35
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, 8-28
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, 8-36, 8-38
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. 5-5
Shift pedal • Make sure that operation is smooth.
• Correct if necessary.
8-40
Brake pedal • Make sure that operation is smooth. Lubricate pedal pivoting point
if necessary. 8-40
ITEM ROUTINE PAGE
UBW262E0.book Page 2 Tuesday, April 3, 2018 10:59 AM

5-5
5Brake 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 8-29.)
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 8-36.)EBU19818TiresCheck 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)
UBW262E0.book Page 5 Tuesday, April 3, 2018 10:59 AM

5-6
5
Tire 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
2. Tire air valve
1
2
1. Tire tread depth
UBW262E0.book Page 6 Tuesday, April 3, 2018 10:59 AM

8-2
8
EBU29573Owner’s Manual and tool kitBe sure to always keep the Owner’s Manual, the
tool kit and the low-pressure tire gauge with the
vehicle. Make sure to protect the Owner’s Manual
by putting it in the plastic bag, then by placing the
bag in the document pouch.
The information included in this manual and the
tools provided in the tool kit are intended to assist
you in the performance of preventive maintenanceand minor repairs. However, additional tools such
as a torque wrench are necessary to perform cer-
tain maintenance work correctly.
TIPIf you do not have the tools or experience required
for a particular job, have a Yamaha dealer perform
it for you.
1. Owner’s Manual
2. Low-pressure tire gauge
3. Tool kit
1
2
3
UBW262E0.book Page 2 Tuesday, April 3, 2018 10:59 AM

8-6
8
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
UBW262E0.book Page 6 Tuesday, April 3, 2018 10:59 AM

10-3
10
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/MS22Tire 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
Spring:
Coil spring
UBW262E0.book Page 3 Tuesday, April 3, 2018 10:59 AM