2021 YAMAHA YFZ50 ECU

DIC183
YFZ50
OWNER’S MANUAL
MANUEL DU PROPRIÉTAIRE MANUAL DEL PROPIETARIO
BW4-F8199-64
READ THIS MANUAL CAREFULLY!
It contains important safety information.
LIRE ATTENTIVEMENT CE MANUEL!
Il comprend d’importantes informations de sécurité.
¡LEA ESTE MANUAL ATENTAMENTE!
Contiene indicaciones importantes acerca de la seguridad.

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.
UBW464E0.book Page 3 Thursday, January 23, 2020 2:42 PM

5-3
5
When your child has developed sufficient skill to
no longer need you to follow with the lanyard,
securely tie up the lanyard. However, you must
still closely supervise your child at all times dur-
ing ATV operation.
EBU18286Throttle leverPush the throttle lever to increase engine speed.
Spring tension returns the lever to the rest position
when released. Always check that the throttle le-
ver returns normally before starting the engine.
EBU36330Speed limiterYour ATV was delivered with two speed limiter de-
vices. A vehicle speed limiter adjusting screw and
a removable engine speed limiter plate. Yamaha
recommends that all beginning riders start off with
the vehicle speed limiter adjusting screw fully
turned in and the engine speed limiter plate in-
stalled to limit the amount of speed available while
they learn.
The vehicle speed limiter keeps the throttle from
fully opening, even when the throttle lever is
pushed to the maximum. The adjusting screw may
be gradually turned out as the beginner becomes
more familiar with operating the ATV. Parents
should decide when to adjust the ATV for more
power as their youngster’s riding skills improve.
Once the ATV rider can operate with skill at the top
speed permitted by adjusting the vehicle speed
limiter alone, the engine speed limiter plate can be
removed. Since removal of this plate will result in
a significant increase in power, turn the vehicle
speed limiter adjusting screw completely back in
again and adjust it out in stages as done previous-
ly.
1. Throttle lever
1
UBW464E0.book Page 3 Thursday, January 23, 2020 2:42 PM

5-9
5of sparks, open flames, or other sources of
ignition such as the pilot lights of water heat-
ers and clothes dryers.
2. Do not overfill the fuel tank. When refueling, be sure to insert the pump nozzle into the fuel
tank filler hole. Stop filling when the fuel
reaches the bottom of the filler tube. Because
fuel expands when it heats up, heat from the
engine or the sun can cause fuel to spill out of
the fuel tank. 3. Wipe up any spilled fuel immediately.
NOTICE: Immediately wipe off spilled fuel
with a clean, dry, soft cloth, since fuel may
deteriorate painted surfaces or plastic
parts.
[ECB00982]
4. Turn the fuel tank cap fully clockwise to make sure it is securely closed.EBU38650FuelMake sure there is sufficient gasoline in the tank
before starting off. Refuel if necessary.
WARNING
EWB02532Gasoline is poisonous and can cause injury or
death. Handle gasoline with care. Never siphon
gasoline by mouth. If you should swallow some
gasoline or inhale a lot of gasoline vapor, or get
some gasoline in your eyes, see your doctor
immediately. If gasoline spills on your skin,
wash with soap and water. If gasoline spills on
your clothing, change your clothes.
1. Maximum fuel level
2. Fuel tank filler tube
2 1
UBW464E0.book Page 9 Thursday, January 23, 2020 2:42 PM

5-13
5
EBU36431SeatTo remove the seat
Push down on the rear of the seat and pull the seat
lock lever upward to release the seat lock. Then
pull up at the rear of the seat to remove it.To install the seat
Insert the projections on the front of the seat into
the seat holders, and then push down on the seat
at the rear to lock it in place. Make sure that the
seat is securely fitted.
EBU19027Rear shock absorberThe spring preload can be adjusted to suit the rid-
er’s weight and the riding conditions.
1. Seat
2. Seat lock lever
1
2
1. Projection
2. Seat holder
2
1
UBW464E0.book Page 13 Thursday, January 23, 2020 2:42 PM

7-5
7
EBU20911Accessories and loadingEBU20922Genuine Yamaha Accessories
Choosing accessories for your ATV is an impor-
tant decision. Genuine Yamaha Accessories,
which are available only from a Yamaha dealer,
have been designed, tested, and approved by
Yamaha for use on your ATV. Many companies with no connection to Yamaha manufacture parts
and accessories or offer other modifications for
Yamaha vehicles. Yamaha is not in a position to test the products that these aftermarket compa-
nies produce. Therefore, Yamaha can neither en-
dorse nor recommend the use of accessories not
sold by Yamaha or modifications not specifically
recommended by Yamaha, even if sold and in-
stalled by a Yamaha dealer.
Aftermarket parts, accessories, and modifica-
tions
While you may find aftermarket products similar in
design and quality to genuine Yamaha Accesso-
ries, recognize that some aftermarket accessories
or modifications are not suitable because of po-
tential safety hazards to you or others. Installing aftermarket products or having other modifica-
tions performed to your ATV that change any of
the vehicle’s design or operation characteristics
can put you and others at greater risk of serious
injury or death. You are responsible for injuries re-
lated to changes in the vehicle.
Keep the following in mind when considering an
accessory or operating an ATV which has acces-
sories.

Accessories should be rigidly and securely
mounted. An accessory which can shift position
or come off while you are riding could affect
your ability to control the ATV.
 Do not mount an accessory where it could inter-
fere with your ability to control the ATV. Exam-
ples include (but are not limited to) a heavy or
bulky object attached to the handlebars which
could make steering difficult, an accessory that
limits your ability to move around on the seat, or
one that limits your view.
 Use extra caution when riding an ATV with ac-
cessories. The ATV may handle differently than
it does without accessories.UBW464E0.book Page 5 Thursday, January 23, 2020 2:42 PM

7-6
7
EBU33880Loading
WARNING
EWB00821Never exceed the stated load capacity for this
ATV. Overloading this ATV or carrying or tow-
ing cargo improperly could cause changes in
ATV handling which could lead to an accident.
Cargo should be properly distributed and se-
curely attached. Reduce speed when carrying
cargo or pulling a trailer. Allow greater dis-
tance for braking. As originally equipped, this ATV is not designed to
carry cargo or tow a trailer. If you choose to add
accessories so that you can carry cargo or tow a
trailer, you must use common sense and good
judgment as the stability and handling of an ATV
can be changed. When adding accessories, keep
the following points in mind:
Never exceed the weight limits shown. An over-
loaded ATV can be unstable. 
If you are carrying cargo and towing a trailer, in-
clude the tongue weight in the maximum ATV
load limit.
 Load cargo on the carriers as close to the center
of the ATV as possible. Put cargo at the rear of
the front carrier, at the front of the rear carrier,
and center it.
 Tie down cargo securely to the carriers. Make
sure cargo in the trailer cannot move around. A
shifting load can cause an accident.
 Make sure the load does not interfere with con-
trols or your ability to see where you are going.
 Ride more slowly than you would without a
load. The more weight you carry, the slower you
should go.
 Allow more braking distance. A heavier ATV
takes longer to stop.
 Avoid making sharp turns unless at very slow
speeds.
 Avoid hills and rough terrain. Choose terrain
carefully. Added weight affects the stability and
handling of the ATV.
MAXIMUM LOADING LIMIT ATV loading limit (total weight of rider, car-
go, accessories, and tongue weight):41.0 kg (90 lb)UBW464E0.book Page 6 Thursday, January 23, 2020 2:42 PM