tires YAMAHA YFM90 2017 User Guide

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
UBD361E0.book Page 18 Monday, January 25, 2016 10:53 AM

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. √ √√√
8Drive chain • Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if neces-
sary.
• Clean and lubricate. √√√√√
9 *Drive chain rollers • Check for wear and replace if necessary. √√√
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) 320
(200) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320UBD361E0.book Page 6 Monday, January 25, 2016 10:53 AM

8-25
8
TIPAfter adjusting the brake lever free play, check the
rear brake shoes for wear. EBU34013Drive chain slackThe drive chain slack should be checked before
each ride and adjusted if necessary.
To check the drive chain slack1. Place the ATV on a level surface.
TIPWhen checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground. 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.
1. Rear brake lever free play adjusting nut
1
(a)
(b)
Drive chain slack:24.0–32.0 mm (0.94–1.26 in)1. Drive chain slack
1
UBD361E0.book Page 25 Monday, January 25, 2016 10:53 AM

9-3
9
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alterna-
tively, turn the wheels a little every month in
order to prevent the tires from becoming de-
graded 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. Store it in a cool, dry place and charge it once a
month. Do not store the battery in an exces-
sively cold or warm place [less than 0 °C (30
°F) or more than 30 °C (90 °F)]. For more infor-
mation on storing the battery, see page 8-31.
TIPMake any necessary repairs before storing the
ATV. UBD361E0.book Page 3 Monday, January 25, 2016 10:53 AM

10-3
10
Tire air pressure (measured on cold tires):Recommended:Front: 24.0 kPa (0.240 kgf/cm², 3.5 psi)
Rear: 24.0 kPa (0.240 kgf/cm², 3.5 psi)
Minimum:
Front: 20.7 kPa (0.207 kgf/cm², 3.0 psi)
Rear:
20.7 kPa (0.207 kgf/cm², 3.0 psi)Front wheel:Wheel type:Panel wheel
Rim size:
8 x 5.5ATRear wheel:Wheel type:Panel wheel
Rim size:
8 x 5.5ATFront brake:Type:Mechanical leading, trailing drum brake
Operation:
Right hand operationRear brake:Type:Mechanical leading, trailing drum brake
Operation:
Left hand operation
Front suspension:Type:Swing axle
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel: 126 mm (5.0 in)Rear suspension:Type:
Swingarm
Spring/shock absorber type: Coil spring/oil damper
Wheel travel: 145 mm (5.7 in)Electrical system:Ignition system:CDI
Charging system: AC magnetoBattery:Model:GTX5L-BS
Voltage, capacity: 12 V, 4.0 AhBulb voltage, wattage × quantity:Neutral indicator light:
12 V, 3.5 W × 1
Reverse indicator light: 12 V, 3.5 W × 1
UBD361E0.book Page 3 Monday, January 25, 2016 10:53 AM

12-2
12
Parking brake ................................................................. 4-5
Parking on a slope ......................................................... 6-5
Part locations ................................................................. 3-1RReverse indicator light ................................................... 4-1
Riding your ATV ............................................................. 7-1SSafety information .......................................................... 2-1
Seat .............................................................................. 4-12
Shock absorber assemblies, adjusting the front ......... 4-13
Shock absorber assembly, adjusting the rear ............. 4-14
Spark arrester, cleaning ............................................... 8-18
Spark plug, checking ..................................................... 8-9
Specifications .............................................................. 10-1
Speed limiter .................................................................. 4-3
Starter (choke) ............................................................. 4-11
Start switch .................................................................... 4-2
Steering shaft, lubricating ............................................ 8-30
Storage .......................................................................... 9-2TThrottle lever ...........................................................4-2, 5-3
Throttle lever free play, adjusting ................................ 8-20
Tires ............................................................................... 5-3
Transmission oil ....................................................5-3, 8-14
Troubleshooting ........................................................... 8-35
Troubleshooting chart .................................................. 8-36VValve clearance ............................................................ 8-21
Vehicle identification number ...................................... 11-1WWheel hub bearings, checking .................................... 8-29Wheel, installing ........................................................... 8-34
Wheel, removing .......................................................... 8-34
UBD361E0.book Page 2 Monday, January 25, 2016 10:53 AM