2009 YAMAHA YFM90R service

5-1

PRE-OPERATION CHECKS
Pre-operation check listBefore operating this ATV, be sure to check the items listed in the following table.TIPThe maintenance of some items in the table has to be performed by a Yamaha dealer. Refer to the "Periodicmaintenance and lubrication charts" on page 8-3 to determine which service should be performed by a
Yamaha dealer.
5

WARNING
Always inspect your ATV each time you use it to make sure it is in safe operating condition.
Always follow the inspection and maintenance procedures and schedules described in the Owner’sManual. Failure to inspect increases the possibility of an accident or equipment damage.

8-1
PERIODIC MAINTENANCE AND MINOR REPAIR
Safety is an obligation of the owner. Periodic in-
spection, adjustment and lubrication will keep your
ATV in the safest and best operating condition
possible. The most important points of inspection,
adjustment, and lubrication are explained on the
following pages.
The intervals given in the periodic maintenance
and lubrication chart should be considered as a
general guide under normal riding conditions.
However, DEPENDING ON THE WEATHER,
TERRAIN, GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORTENED.
Owner’s manual and tool kit Be sure to put this owner’s manual in the plastic
bag and to always carry it as well as the owner’s
tool kit and the low-pressure tire gauge in their re-
spective compartments under the seat.
8
WARNING
Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or start fires. Turn off the en-
gine when performing maintenance unlessotherwise specified. Have a Yamaha dealer
perform the service if you are not familiar with
maintenance work.

8-2
it for you.
1. Owner ’s manual
2. Low-pressure tire gauge
3. Owner ’s tool kitThe service information included in this manual
and the tools provided in the owner’s tool kit are in-
tended to assist you in the performance of preven-
tive maintenance and minor repairs. However,
additional tools such as a torque wrench may be
necessary to perform certain maintenance work
correctly.
TIPIf you do not have the tools or experience required
for a particular job, have a Yamaha dealer perform
5TH-28199-66YFM90ROWNER'S MANUAL
1626-21-38This ATV
shoul
d not be ridden by anyone under
years.
e
g
a
f
o
WARNING
READ THIS MANUAL CAREFULLY!
It contains important safety information.
8
1
23
WARNING
Never modify this ATV through improper in-
stallation or use of accessories, as it may
cause changes in handling, which in some sit-
uations could lead to an accident. All parts and
accessories added to this ATV should be gen-
uine Yamaha or equivalent components de-
signed for use on this ATV and should be
installed and used according to instructions. If
you have questions, consult an authorizedYamaha ATV dealer.

8-8
TIP
8
The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
Hydraulic brake service Regularly check and, if necessary, correct the brake fluid level.Every two years replace the internal components of the brake master cylinder and caliper, and
change the brake fluid. Replace the brake hoses every four years and if cracked or damaged.

8-22
The throttle cable free play should measure 1.0–
3.0 mm (0.04–0.12 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, have a Yamaha dealer adjust it. Timing chainThe timing chain stretches with use, resulting in im-
proper valve timing and engine noise. To prevent
this from occurring, the timing chain tensioner
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
Valve clearanceThe valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
1. Throttle lever free play
1
BrakesReplacement of brake components requires
professional knowledge.Brake service should be
performed by a Yamaha dealer.
WARNING
Operating with improperly serviced or adjusted
brakes could lead to a loss
in braking ability
and an accident.
8
Checking the front brake shoesThe front brake shoes must be checked for wear at
the intervals specified in the periodic maintenance
and lubrication chart. Front brake is provided with a
wear indicator on front brake lever, which allows you

4. Tighten the lower locknut.
5. While applying the front brake, turn out the up-per adjusting bolt until the upper and lower ca-
ble lengths are equal. The cable joint will
become vertical.1. Upper locknut
2. Upper adjusting bolt
3. Lower locknut
4. Lower adjusting bolt
12
4
3 (a)(b)
(a)
(b)
11. Cable joint6. Tighten the upper locknut.
8-24
8
WARNING
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.

8-27
Checking and lubricating the cables The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
Checking and lubricating the front and
rear brake levers The operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.Recommended lubricant:
Engine oil
8
WARNING
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:Make sure the brakes operate smoothly and
that the free play is correct.Make sure the brakes do not drag.Make sure the brakes are not spongy. All air
must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These proceduresshould be performed by a Yamaha dealer.
WARNING
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could re-
strict the operation of controls and lead to anaccident or injury.

8-34
TroubleshootingAlthough Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the fu-
el, compression, or ignition systems, for example,
can cause poor starting and loss of power.
The following troubleshooting chart represents a
quick and easy procedure for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, expe-
rience, and know-how to service the ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.
8
WARNING
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-lot lights from water heaters or furnaces.