2017 YAMAHA YFZ50 warning

2-8
2
WARNING
EWB00073Avoid Carbon Monoxide Poisoning
All engine exhaust contains carbon monoxide,
a deadly gas. Breathing carbon monoxide can
cause headaches, dizziness, drowsiness, nau-
sea, confusion, and eventually death.
Carbon Monoxide is a colorless, odorless,
tasteless gas which may be present even if you
do not see or smell any engine exhaust. Deadly
levels of carbon monoxide can collect rapidly
and you can quickly be overcome and unable
to save yourself. Also, deadly levels of carbon
monoxide can linger for hours or days in en-
closed or poorly ventilated areas. If you experi-
ence any symptoms of carbon monoxide
poisoning, leave the area immediately, get
fresh air, and SEEK MEDICAL TREATMENT.
Do not run engine indoors. Even if you try to
ventilate engine exhaust with fans or open
windows and doors, carbon monoxide can
rapidly reach dangerous levels.
 Do not run engine in poorly ventilated or par-
tially enclosed areas such as barns, garages,
or carports. 
Do not run engine outdoors where engine
exhaust can be drawn into a building through
openings such as windows and doors.

WARNING
EWB02592When transporting the ATV in another vehicle,
be sure it is kept upright and that the fuel cock
is in the “OFF” position. Otherwise, fuel may
leak out of the carburetor or fuel tank.
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4-4
4The 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.
Vehicle speed limiter
1. Loosen the locknut.
2. To increase the maximum engine power available and the maximum speed of the ATV,
turn the adjusting screw in direction (a). To
decrease the maximum engine power avail-
able and the maximum speed of the ATV, turn
the adjusting screw in direction (b). Do not
turn the adjusting screw out more than 11
mm (0.43 in) or the throttle cable could be
damaged. Always make sure the throttle lever free play is adjusted to 2.0–3.2 mm (0.08–
0.13 in). (See page 8-21.) WARNING! Im-
proper adjustment of the speed limiter and
throttle could cause throttle cable damage
or improper throttle operation. You could
lose control, resulting in an accident.
[EWB00242]
3. Tighten the locknut.1. Locknut
2. Adjusting screw
3. No more than 11 mm (0.43 in)
1
3
2
(b)
(a)
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4-6
4
EBU18402Rear brake leverThe rear brake lever is located on the left handle-
bar. To apply the rear brake, pull the brake lever
toward the handlebar grip.EBU18462Parking brakeUse the parking brake before starting the engine
or after parking the ATV, especially on a slope. Ap-
ply the rear brake lever and push down the lock
plate to apply the parking brake. Squeeze the rear
brake lever to release the parking brake.
WARNING
EWB00221Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.
 Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
1. Rear brake lever
1
1. Parking brake lock plate
1
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4-8
44. When the engine has started, remove thekickstarter lever and store it under the seat.
5. Install the kickstarter lever cap.
NOTICEECB02300Do not use the kickstarter if the battery is not
installed or if the battery leads are not connect-
ed. EBU18721Fuel tank capRemove the fuel tank cap by turning it counter-
clockwise.
EBU18757FuelMake sure there is sufficient gasoline in the tank.
WARNING
EWB02522Gasoline and gasoline vapors are extremely
flammable. To avoid fires and explosions and
to reduce the risk of injury when refueling, fol-
low these instructions. 1. Before refueling, turn off the engine and be sure that no one is sitting on the vehicle. Nev-
er refuel while smoking, or while in the vicinity
1. Kickstarter lever
1
1. Fuel tank cap
1
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4-9
4
of 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.
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
1. Maximum fuel level
2. Fuel tank filler tube
2 1
Recommended fuel:
Regular unleaded gasoline only
For Europe: Regular unleaded gasoline only
with a research octane number of 95 or
higher
Fuel tank capacity: 5.6 L (1.48 US gal, 1.23 Imp.gal)
Fuel reserve amount: 0.7 L (0.18 US gal, 0.15 Imp.gal)
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5-1
5
EBU19203
PRE-OPERATION CHECKS
EBU19226Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWB00482Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected
by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer. Before using this vehicle, check the following points:
ITEMROUTINE PAGE
Fuel • Check fuel level in fuel tank,
and add recommended fuel if neces-
sary.
• Check fuel line for leakage. Correct if necessary. 4-8, 5-3
Engine oil • Check oil level in engine, and add recommended oil to specified
level if necessary.
• Check ATV for oil leakage. Correct if necessary. 5-3, 8-11
Transmission oil • Check ATV for oil leakage. Correct if necessary. 5-3, 8-14
Front brake • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 5-3, 8-22, 8-23
Rear brake • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 5-3, 8-22, 8-25
UBW460E0.book Page 1 Monday, May 23, 2016 11:12 AM

5-4
5Tire pressure
Use the low-pressure tire gauge to check and ad-
just tire pressures when the tires are cold. Tire
pressures 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]
Set tire
pressures to the following specifications:
The low-pressure tire gauge is included as stan-
dard equipment. Make two measurements of the
tire pressure and use the second reading. Dust or
dirt in the gauge could cause the first reading to be
incorrect.Recommended tire pressure:
Front13.8 kPa (0.14 kgf/cm², 2.0 psi)
Rear 13.8 kPa (0.14 kgf/cm², 2.0 psi)
Minimum tire pressure: Front12.4 kPa (0.124 kgf/cm², 1.8 psi)
Rear 12.4 kPa (0.124 kgf/cm², 1.8 psi)
Maximum tire seating pressure: Front250 kPa (2.5 kgf/cm², 36 psi)
Rear 250 kPa (2.5 kgf/cm², 36 psi)
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5-5
5
Tire wear limit
When the tire groove decreases to 3 mm (0.12 in)
due to wear, replace the tire. Tire information
This ATV is equipped with tubeless tires with
valves.
WARNING
EWB02552Use of improper tires on this ATV may cause
loss of control, increasing your risk of an acci-
dent. After extensive tests, only the tires listed below
have been approved for this model by Yamaha
Motor Co., Ltd.
1. Low-pressure tire gauge
1
1. Tire wear limit
UBW460E0.book Page 5 Monday, May 23, 2016 11:12 AM