2018 YAMAHA YFZ50 tires

7-12
7abruptly, the vehicle may lurch forward or the front
wheels may lift off the ground, resulting in a loss of
directional control. Avoid higher speeds until you
are thoroughly familiar with the operation of your
ATV.
When slowing down or stopping, release the
throttle and apply the brakes smoothly and evenly.
Improper use of the brakes can cause the tires to
lose traction, reducing control and increasing the
possibility of an accident.
TURNING YOUR ATV
WARNING
EWB01772Always 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 footboard to the
outside of the turn (opposite your desired direc-
tion) 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.UBW461E0.book Page 12 Tuesday, January 31, 2017 5:13 PM

7-18
7
Never attempt to turn the ATV around on any
hill until you have mastered the turning tech-
nique as described in the Owner’s Manual on
level ground. Be very careful when turning
on any hill.
Traversing a sloping surface on your ATV requires
you to properly position your weight to maintain
proper balance. Be sure that you have learned the
basic riding skills on flat ground before attempting
to cross a sloping surface. Avoid slopes with slip-
pery surfaces or rough terrain that may upset your
balance.
As you travel across a slope, lean your body in the
uphill direction. It may be necessary to correct the
steering when riding on loose surfaces by pointing
the front wheels slightly uphill. When riding on
slopes, be sure not to make sharp turns either up
or down hill.
If your ATV does begin to tip over, gradually steer
in the downhill direction if there are no obstacles
in your path. As you regain proper balance, grad-
ually steer again in the direction you wish to travel. CROSSING THROUGH SHALLOW WATER
WARNING
EWB01642Operating 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.
OK
UBW461E0.book Page 18 Tuesday, January 31, 2017 5:13 PM

8-6
8
5*Wheels • Check runout and for damage, and replace if nec-
essary. √ √√√
6 *Tires • Check tread depth and for damage, and replace if
necessary.
• Check air pressure and balance, and correct if necessary. √ √√√
7 *Wheel hub bearings • Check for looseness or damage, and replace if
necessary. √ √√√
8 *Front arm pivots • Lubricate with lithium-soap-based grease. √√√
9Drive chain • Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if neces-
sary.
• Clean and lubricate. √√√√√
10 *V- b e l t • Check for wear, cracks or other damage, and re-
place if necessary. √ √√√
11 *Chassis fasteners • Make sure that all nuts, bolts, and screws are
properly tightened. √√√√√
12 *Shock absorber as-
semblies • Check operation and correct if necessary.
• Check for oil leakage and replace if necessary.
√√√
13 *Front knuckle piv-
ots • Lubricate with lithium-soap-based grease.
√√√
14 *Steering shaft • Lubricate with lithium-soap-based grease. √√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev-
er comes first month136612
km (mi) 240
(150) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320UBW461E0.book Page 6 Tuesda y, January 31, 2017 5:13 PM

8-26
8
TIPAfter adjusting the brake lever free play, check the
rear brake shoes for wear. EBU34014Drive chain slackThe drive chain slack should be checked before
each ride and adjusted if necessary.TIPWhen checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground.
To check the drive chain slack1. Place the ATV on a level surface.
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. Loosen the bolts and nuts.
1. Rear brake lever free play adjusting nut
1
(a)
(b)
Drive chain slack: 6.0–12.0 mm (0.24–0.47 in)1. Drive chain slack
1
UBW461E0.book Page 26 Tuesday, January 31, 2017 5:13 PM

9-3
9
e. Install the spark plug and the spark plug
cap.
6. Lubricate all control cables and the pivoting points of all levers.
7. Put the frame on stands or blocks to raise all wheels off the ground. (Alternatively, turn the
wheels each month to prevent the tires from
degrading 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. (See page 8-32.)
UBW461E0.book Page 3 Tuesda y, January 31, 2017 5:13 PM

10-3
10
Caster angle:1.10 °
Trail: 10.4 mm (0.41 in)Front tire:Type:Tubeless
Size: AT16 x 6.5-7
Manufacturer/model:
DURO/DI2040Rear tire:Type:Tubeless
Size:
AT16 x 7-7
Manufacturer/model: DURO/DI2041Loading:Maximum loading limit:
41.0 kg (90 lb)
(Total weight of rider, cargo, accessories, and tongue)Tire air pressure (measured on cold tires):Recommended:Front:
13.8 kPa (0.138 kgf/cm², 2.0 psi)
Rear: 13.8 kPa (0.138 kgf/cm², 2.0 psi)
Minimum: Front: 12.4 kPa (0.124 kgf/cm², 1.8 psi) Rear:
12.4 kPa (0.124 kgf/cm², 1.8 psi)
Front wheel:Wheel type:
Panel wheel
Rim size: 7 x 5.2ATRear wheel:Wheel type:
Panel wheel
Rim size: 7 x 5.2ATFront brake:Type:
Mechanical leading, trailing drum brake
Operation: Right hand operationRear brake:Type:
Mechanical leading, trailing drum brake
Operation: Left hand operationFront suspension:Type:
Swing axle
Spring/shock absorber type: Coil spring/oil damper
Wheel travel: 60 mm (2.4 in)
UBW461E0.book Page 3 Tuesda y, January 31, 2017 5:13 PM

12-2
12
Part locations ................................................................. 3-1RRiding your ATV ............................................................. 7-1SSafety information .......................................................... 2-1
Seat .............................................................................. 4-12
Shock absorber, adjusting the rear ............................. 4-13
Spark arrester, cleaning ............................................... 8-19
Spark plug, checking ..................................................... 8-9
Specifications .............................................................. 10-1
Speed limiter .................................................................. 4-3
Starter (choke) ............................................................. 4-11
Start switch .................................................................... 4-2
Steering shaft, lubricating ............................................ 8-31
Storage .......................................................................... 9-2TThrottle lever ...........................................................4-3, 5-3
Throttle lever free play, adjusting ................................ 8-21
Tires ............................................................................... 5-3
Transmission oil ....................................................5-3, 8-14
Troubleshooting ........................................................... 8-37
Troubleshooting chart .................................................. 8-38VValve clearance ............................................................ 8-22
Vehicle identification number ...................................... 11-1WWheel hub bearings, checking .................................... 8-30
Wheel, installing ........................................................... 8-36
Wheel, removing .......................................................... 8-35
UBW461E0.book Page 2 Tuesday, January 31, 2017 5:13 PM