2009 YAMAHA YFM90R engine

Read this manual carefully before operating this vehicle.This manual should stay with this ve-
hicle if it is sold.
EC Declaration of Conformity
conforming to Directive 98/37/EC
We, YAMAHA MOTOR CO.,LTD. 2500 Shingai, Iwata, Japan,declare in sole responsibility, that the product
YFM90RY (RK1AB07W080000001~)
(Make, model)
to which this declaration applies, conforms to the essential health
and safety requirements of Directive 98/37/EC,(If applicable)and to the other relevant Directives of EEC98/336/EEC or 2004/108/EC(Title and/or number and date of issue of the other Directives of EEC)
(If applicable)To effect correct application of the essential health and safety requirements
stated in the Directives of EEC, the following-standards and/or technical
specifications were consulted: EN292 ANSI/SVIA 1-2007
(Title and/or number and date of issue of standards and/or specifications)
Manufacturer
E-TON POWER TECH.,LTD
498, Section2, Bentian Road, Tainan, TAIWAN
Authorized Representative
YAMAHA MOTOR EUROPE N.V.
Koolhovenlaan 101,1119NC Schiphol-Rijk,The Netherlands
Signature ________________
Shinya Shimada
General Manager
RV Engineering Division
RV Company
Date of Issue19 February, 2008

in skills, physical abilities and judgment. Some children may not be able to operate an ATV safely. Parents
should supervise their child’s use of the ATV at all times. Parents should permit continued use only if they
determine that the child has the ability to operate the ATV safely.Your ATV was delivered with an adjustable speed limiter . Yamaha recommends that all beginners start off
to limit the amount of speed available while they learn. 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 limiter will result in a significant increase in power, turn the
vehicle speed limiter adjusting screw completely back in again; adjust it out in stages as done previously.
If your child is a beginner or is inexperienced, he or she should take a training course.

TABLE OF CONTENTS
SAFETY INFORMATION..............................1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS............................2-1DESCRIPTION ..............................................3-1 Left view.....................................................3-1Right view...................................................3-1
Controls and instruments...........................3-2
INSTRUMENT AND CONTROL
FUNCTIONS..................................................4-1 Main switch...............................................4-1
Handlebar switches ................................... 4-2
Throttle lever ............................................. 4-3
Speed limiters............................................. 4-3
Front brake lever ........................................ 4-6
Rear brake lever ....................................... 4-6
Parking brake ............................................ 4-7
Fuel tank cap ............................................ 4-8 Fuel ........................................................... 4-8
Fuel cock .............................................. 4-10
Choke ..................................................... 4-11
Seat ........................................................ 4-11
PRE-OPERATION CHECKS.........................5-1 Pre-operation check list............................5-1
Fuel ........................................................... 5-3
Engine oil .................................................. 5-3
Final transmission oil ................................ 5-3
Front and rear brakes ............................... 5-3
Throttle lever ............................................. 5-4
Tires .......................................................... 5-4
Measuring the tire pressure ...................... 5-5
Tire wear limit ........................................... 5-6
Chassis fasteners ..................................... 5-7
Instruments and switches ......................... 5-7
OPERATION................................................6-1 Starting a cold engine ............................... 6-1
Starting a warm engine ............................. 6-3
Engine break-in ........................................ 6-4
Parking ..................................................... 6-4
Parking on a slope ................................... 6-5
Accessories and loading .......................... 6-6
Vehicle speed limiter ................................. 4-4
Engine speed limiter plate.......................... 4-5 Kick starter
............................................. 4-12

Cleaning the spark arrester ...................... 8-19
Adjusting the carburetor ........................... 8-20
Adjusting the engine idling speed ............ 8-20
Checking the throttle cable free play ....... 8-21
Timing chain ............................................ 8-22
Valve clearance ....................................... 8-22
Checking the front brake shoes................ 8-22
Adjusting the front brake lever free play ....................................................... 8-23
Checking the rear brake pads ................. 8-25
Checking the brake fluid level ................. 8-25
Changing the rear brake fluid .................. 8-26
Checking the rear brake lever free play ........................................................8-26
Checking and lubricating the cables........ 8-27
Checking and lubricating the front and rear brake levers............................... 8-27
Checking the wheel hub bearings ............ 8-28
Battery ..................................................... 8-28
Replacing the fuse ................................... 8-30
Removing a wheel ................................... 8-32
Installing a wheel ..................................... 8-33
Troubleshooting ....................................... 8-34
Troubleshooting chart .............................. 8-35
RIDING YOUR ATV ...................................... 7-1
GETTING TO KNOW YOUR ATV...............7-2
RIDE WITH CARE AND GOOD JUDGEMENT ............................................ 7-2
BE CAREFUL WHERE YOU RIDE...........7-11
TURNING YOUR ATV..............................7-15
CLIMBING UPHILL....................................7-17
RIDING DOWNHILL..................................7-20
CROSSING A SLOPE................................7-21
CROSSING THROUGH SHALLOW WATER ................................................... 7-22
RIDING OVER ROUGH TERRAIN...........7-24
SLIDING AND SKIDDING.........................7-25
WHAT TO DO IF.......................................7-26
WHAT TO DO... ........................................ 7-26
PERIODIC MAINTENANCE AND MINOR
REPAIR..........................................................8-1 Owner’s manual and tool kit ...................... 8-1
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
Final transmission oil ................................ 8-14
Cleaning the air filter element .................. 8-15 CLEANING AND STORAGE.........................9-1
Cleaning ..................................................... 9-1
Storage ...................................................... 9-2 Brakes ..................................................... 8-22

1-1
1

SAFETY INFORMATION
AN ATV IS NOT A TOY AND CAN BE HAZARD-OUS TO OPERATE.An ATV handles differently from other vehicles, in-
cluding motorcycles and cars. A collision or roll-
over can occur quickly, even during routine
maneuvers such as turning and riding on hills or
over obstacles, if you fail to take proper precau-
tions.
SEVERE INJURY OR DEATH can result if you do
not follow these instructions:Read this manual and all labels carefully and fol-
low the operating procedures described.Never operate an ATV without proper training or
instruction.
Always follow the age recommendation:– A child under 12 years old should never oper-
ate an ATV with engine size greater than 70 cc.
– A child under 16 years old should never oper-
ate an ATV with engine size greater than 90 cc.
Never allow a child under age 16 to operate an
ATV without adult supervision, and never allow
continued use of an ATV by a child if he or she
does not have the abilities to operate it safely.Never carry a passenger on an ATV.Always avoid operating an ATV on any paved
surfaces, including sidewalks, driveways, park-
ing lots and streets.Never operate an ATV on any paved street,
paved road or motorway.Never operate an ATV without wearing an ap-
proved motorcycle helmet that fits properly. You
should also wear eye protection (goggles or face
shield), gloves, boots, a long-sleeved shirt or a
jacket, and long pants.Never consume alcohol or drugs before or whileWatch carefully for other vehicles when operat
-ing on unpaved public streets or roads. Make
sure you know your country’s laws and regula
-tions before you ride on unpaved public streets
or roads.

1-3
1
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 re-
duce the chance of skidding or sliding out of con-
trol.Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may havereduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.
Always use the size and type of tires specified in
this manual.Always maintain proper tire pressure as de-
scribed in this manual.Never modify an ATV through improper installa-
tion or use of accessories.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.
WARNING
Always turn off the engine when refueling.Do not refuel right after the engine has been
running and is still very hot.Do not spill gasoline on the engine or ex-
haust pipe/muffler when refueling. Never re-
fuel while smoking, or in the vicinity of
sparks, open flames, or other sources of ig-
nition such as the pilot lights of water heat-
ers and clothes dryers. Gasoline can catch

1-4
1
fire and you could be burned.When transporting the ATV in another vehi-
cle, 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.Gasoline is poisonous. If you should swal-
low some gasoline or inhale a lot of gasoline
vapor, or get some gasoline in your eyes,
seek medical help immediately. If gasoline
spills on your skin, wash with soap and wa-
ter. If gasoline spills on your clothing,change your clothes.
WARNING
Always operate your ATV in an area with ade-
quate ventilation. Never start or run the engine
in a closed area. Exhaust fumes are poisonous
and may cause loss of consciousness and
death within a short time.

4-1
4
INSTRUMENT AND CONTROL FUNCTIONS
Main switch The positions of the main switch are as follows:
ON
All electrical systems are supplied with power, and
the engine can be started. The key cannot be re-
moved.
OFF
All electrical systems are off. The key can be re-
moved.
1. Main switch
O F F
O
I
ITI
NG
N
1
ON
OFF