2021 YAMAHA YFZ50 tire size

3-3
3surfaces. Shift your weight to the uphill side of
the ATV. Never attempt to turn the ATV around
on any hill until you have mastered the turning
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. 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.
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3-6
3
TEACHING YOUR CHILD TO OPERATE THE
ATV
WARNING
EWB00081Never let your child ride an ATV without close
adult supervision (a child under 6 should not
ride this ATV even with adult supervision).
Promptly correct your child if he or she begins
to ride beyond his or her abilities and, if neces-
sary, intervene by pulling the cord (lanyard) to
stop the engine.
If the child rides beyond his or her abilities, or
rides in terrain that is too difficult, he or she
may lose control of the ATV, causing an acci-
dent.
Introduce new riding areas slowly and make
sure the riding area matches your child’s skill
level. You must make the commitment to your child’s
proper use of the ATV. Your child must rely upon
you to be sure he or she has the development,
proper training, and proper equipment, as well as
an appropriately sized ATV and an appropriate rid-
ing area. Be sure your child is ready to learn how to ride
As a parent, your first step is to decide when your
child has the strength, skills, and judgment to
learn how to operate an ATV safely. Re-evaluate
your child’s readiness before every use; a child
who is too tired or distracted should not be al-
lowed to operate the ATV.
Be sure your child is properly trained
Your child should take a certified training course.
Training will continue with you as the instructor, so
you should be sure you thoroughly understand
proper riding techniques before continuing to in-
struct your child. Go through this Owner’s Manual
page by page with your child and be sure he or
she understands how to operate the ATV properly.
Be sure your child is wearing all the proper
safety equipment
Your child must always wear an approved motor-
cycle helmet that fits properly. Your child should
also wear the safety equipment described in the
Riding Your ATV section of this manual.UBW464E0.book Page 6 Thursday, January 23, 2020 2:42 PM

6-5
6Tire 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. Aftermarket tires and rims
The tires and rims that came with your ATV were
designed to match the performance capabilities
and to provide the best combination of handling,
braking, and comfort. Other tires, rims, sizes, and
combinations may not be appropriate.
WARNING
EWB02552Use of improper tires on this ATV may cause
loss of control, increasing your risk of an acci-
dent.
1. Tire tread depth
Front:
Manufacturer/model:DURO/DI2040
Size: AT 1 6 x 6 . 5 - 7
Rear: Manufacturer/model:DURO/DI2041
Size: AT 1 6 x 7 - 7
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11-3
11
Transmission type:CVT automatic
Gear ratio: Transmission ratio:2.140–0.710 : 1
Forward gear: 10.967 (49/15 x 47/14)Front tire:Size:AT16x6.5-7
Manufacturer/model: DURO/DI2040Rear tire:Size:AT16x7-7
Manufacturer/model: DURO/DI2041Tire air pressure (measured on cold tires):Vehicle load:0.0–41.0 kg (0–90 lb)
Recommended: Front:15.0 kPa (0.150 kgf/cm², 2.2 psi)
Rear: 15.0 kPa (0.150 kgf/cm², 2.2 psi)
Minimum:
Front:12.0 kPa (0.120 kgf/cm², 1.7 psi)
Rear:
12.0 kPa (0.120 kgf/cm², 1.7 psi)
Front wheel:Rim size:7 x 5.2ATRear wheel:Rim size:7 x 5.2ATFront brake:Type:
Mechanical leading, trailing drum brakeRear brake:Type:Mechanical leading, trailing drum brakeFront suspension:Type:Swing axle
Spring: Coil spring
Shock absorber:
Gas-hydraulic damper
Wheel travel: 60 mm (2.4 in)Rear suspension:Type:
Swingarm
Spring: Coil spring
Shock absorber: Gas-hydraulic damper
Wheel travel:
51 mm (2.0 in)
UBW464E0.book Page 3 Thursday, January 23, 2020 2:42 PM