2017 YAMAHA YFM90 brake

EBU17421
TABLE OF CONTENTS
LOCATION OF THE WARNING AND
SPECIFICATION LABELS .............................. 1-1
SAFETY INFORMATION ................................ 2-1
DESCRIPTION................................................ 3-1Left view ...................................................... 3-1
Right view.................................................... 3-1
Controls and instruments............................ 3-2
INSTRUMENT AND CONTROL
FUNCTIONS ................................................... 4-1 Main switch ................................................. 4-1
Indicator lights............................................. 4-1
Handlebar switches .................................... 4-2
Throttle lever ............................................... 4-2
Speed limiter ............................................... 4-3
Front brake lever ......................................... 4-4
Rear brake lever .......................................... 4-5
Parking brake .............................................. 4-5
Drive select lever ......................................... 4-6
Kickstarter ................................................... 4-7
Fuel tank cap .............................................. 4-8
Fuel ............................................................. 4-8 Fuel cock .................................................. 4-10
Starter (choke) ......................................... 4-11
Seat .......................................................... 4-12
Adjusting the front shock absorber
assemblies .............................................. 4-13
Adjusting the rear shock absorber assembly ................................................ 4-14
PRE-OPERATION CHECKS .......................... 5-1 Fuel ............................................................. 5-3
Engine oil .................................................... 5-3
Transmission oil .......................................... 5-3
Front and rear brakes ................................. 5-3
Throttle lever ............................................... 5-3
Drive chain .................................................. 5-3
Tires ............................................................ 5-3
Chassis fasteners ....................................... 5-6
Instruments and switches........................... 5-6
OPERATION .................................................. 6-1 Starting a cold engine................................. 6-1
Starting a warm engine............................... 6-3
Operating the drive select lever and driving in reverse ...................................... 6-3UBD361E0.book Page 1 Monday, January 25, 2016 10:53 AM

Engine break-in ........................................... 6-4
Parking ........................................................ 6-5
Parking on a slope ...................................... 6-5
Accessories and loading ............................. 6-6
RIDING YOUR ATV ........................................ 7-1 GETTING TO KNOW YOUR ATV ................ 7-2
RIDE WITH CARE AND GOOD JUDGMENT .............................................. 7-2
BE CAREFUL WHERE YOU RIDE ............... 7-9
TURNING YOUR ATV................................ 7-12
CLIMBING UPHILL ................................... 7-13
RIDING DOWNHILL .................................. 7-16
CROSSING A SLOPE................................ 7-17
CROSSING THROUGH SHALLOW WATER .................................................... 7-18
RIDING OVER ROUGH TERRAIN ............. 7-20
SLIDING AND SKIDDING .......................... 7-20
WHAT TO DO IF... ..................................... 7-21
WHAT TO DO... ......................................... 7-22
PERIODIC MAINTENANCE AND
ADJUSTMENT................................................ 8-1 Owner’s manual and tool kit ....................... 8-2
Periodic maintenance chart for the emission control system ........................... 8-3 General maintenance and lubrication
chart.......................................................... 8-5
Checking the spark plug............................. 8-9
Engine oil .................................................. 8-11
Transmission oil ........................................ 8-14
Cleaning the air filter element ................... 8-15
Cleaning the spark arrester ...................... 8-18
Adjusting the carburetor ........................... 8-19
Adjusting the engine idling speed ............ 8-19
Adjusting the throttle lever free play ......... 8-20
Valve clearance......................................... 8-21
Brakes....................................................... 8-21
Checking the front and rear brake shoes ...................................................... 8-21
Adjusting the front brake lever free play... 8-22
Adjusting the rear brake lever free play .... 8-24
Drive chain slack....................................... 8-25
Lubricating the drive chain ....................... 8-27
Checking and lubricating the cables ........ 8-28
Checking and lubricating the front and rear brake levers ..................................... 8-29
Checking the wheel hub bearings ............ 8-29
Lubricating the front knuckle pivots ......... 8-30
Lubricating the steering shaft ................... 8-30
Battery ...................................................... 8-31
Replacing the fuse .................................... 8-33
Removing a wheel .................................... 8-34
UBD361E0.book Page 2 Monday, January 25, 2016 10:53 AM

2-3
2technique 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. To avoid stall-
ing, use the proper gear and maintain a steady
speed 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 be sure there are no obstacles or people
behind you when you operate in reverse. When
it is safe to proceed in reverse, go slowly.
 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.
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3-2
3
EBU17714Controls and instrumentsTIPThe ATV you have purchased may differ slightly
from the figures shown in this manual. 1. Rear brake lever
2. Handlebar switches
3. Parking brake lock plate
4. Starter (choke)
5. Main switch
6. Throttle lever
7. Front brake lever
8. Drive select lever
1
2
3
5
6
7
4
8
UBD361E0.book Page 2 Monday, January 25, 2016 10:53 AM

4-4
4
3. Tighten the locknut.
Engine speed limiter plate
When the engine speed limiter plate is installed,
engine speed is limited to 4900 r/min. When this
plate is removed, top engine speed (8500 r/min) is
available.
Remove the plate as follows. 1. Remove the seat. (See page 4-12.)
2. Loosen the screws, and then remove the plate as shown. 3. Tighten the screws.
4. Install the seat.
TIPStore the engine speed limiter plate with the own-
er’s manual so that it is readily available whenever
you want to reduce top engine speed. EBU18392Front brake leverThe front brake lever is located on the right han-
dlebar. To apply the front brake, pull the brake le-
ver toward the handlebar grip.
1. Locknut
2. Adjusting screw
3. No more than 10 mm (0.39 in)
1
3
2
(b)
(a)
1. Screw
2. Engine speed limiter plate
12
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4-5
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.
1. Front brake lever
1
1. Rear brake lever
1
UBD361E0.book Page 5 Monday, January 25, 2016 10:53 AM

4-6
4
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 braking performance which could cause an
accident. You could also wear out the brakes
prematurely.
EBU18582Drive select leverThe drive select lever is used to shift your ATV into
the forward, neutral and reverse positions. See the
“Operating the drive select lever and driving in re-
verse” section on page 6-3 for the drive select le-
ver operation.
1. Parking brake lock plate
1
1. Drive select lever
1
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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, 8-21, 8-22
Rear brake • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 5-3, 8-21, 8-24
UBD361E0.book Page 1 Monday, January 25, 2016 10:53 AM