Yamaha YFM66FGX User manual

READ THIS MANUAL CAREFULLY!
It contains important safety information.
This ATV should not be ridden by anyone under 16 years of age.
WARNING
OWNER’S MANUAL
23D-28199-10LIT-11626-21-03
YFM66FGX
DIC2342

EBU17091
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

EBU17170
INTRODUCTION
EBU17270
Congratulations on your purchase of the Yamaha YFM66FGX. This ATV represents the result of many
years of Yamaha experience in the production of fine sporting, touring, and pace-setting racing machines.
With the purchase of this Yamaha, you can now appreciate the high degree of craftsmanship and reliability
that have made Yamaha a leader in these fields.
This manual will provide you with a good basic understanding of the features and operation of this ATV.
This manual includes important safety information. It provides information about special tech-
niques and skills necessary to ride the ATV. It also includes basic maintenance and inspection proce-
dures. If you have any questions regarding the operation or maintenance of your ATV, please consult a
Yamaha dealer.
AN IMPORTANT SAFETY MESSAGE:
●READ THIS MANUAL TOGETHER WITH TIPS FOR THE ATV RIDER CAREFULLY AND COMPLETE-
LY BEFORE OPERATING YOUR ATV. MAKE SURE YOU UNDERSTAND ALL INSTRUCTIONS.
●PAY CLOSE ATTENTION TO THE WARNING AND CAUTION LABELS ON THE ATV.
●NEVER OPERATE AN ATV WITHOUT PROPER TRAINING OR INSTRUCTION. FREE TRAINING IS
AVAILABLE TO ANYONE WHO BUYS A NEW ATV. CALL 1-800-887-2887 FOR MORE INFORMA-
TION.
●THIS ATV, AND ANY OTHER ATV OVER 90 cc, SHOULD NOT BE RIDDEN BY ANYONE UNDER 16
YEARS OF AGE.
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

EBU17330
IMPORTANT MANUAL INFORMATION
EBU17341
FAILURE TO FOLLOW THE WARNINGS CONTAINED IN THIS MANUAL CAN RESULT IN SERIOUS IN-
JURY OR DEATH.
Particularly important information is distinguished in this manual by the following notations:
* Product and specifications are subject to change without notice.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failure to follow WARNING instructions could result in severe injury
or death to the ATV operator, a bystander, or a person inspecting or
repairing the ATV.
A CAUTION indicates special precautions that must be taken to avoid
damage to the ATV.
A NOTE provides key information to make procedures easier or clearer.
WARNING
CAUTION:
NOTE:
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

EBU17350
IMPORTANT NOTICE
EBU17360
Welcome to the Yamaha world of motor sports!
This ATV is designed and manufactured for OFF-ROAD use only. It is illegal and unsafe to operate this ATV
on any public street, road or highway.
This ATV complies with all applicable OFF-ROAD noise level and spark arrester laws and regulations in
effect at the time of manufacture.
Please check your local riding laws and regulations before operating this ATV.
EBU17381
AFFIX DEALER
LABEL HERE
YFM66FGX
OWNER’S MANUAL
©2007 by Yamaha Motor Corporation, U.S.A.
1st edition, March 2007
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation, U.S.A.
is expressly prohibited.
Printed in Japan.
P/N LIT-11626-21-03
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

WARNING
EWB00010
Indicates a potential hazard that could result
in serious injury or death.
EBU17420
TABLE OF CONTENTS
SAFETY INFORMATION .............................. 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS ............................ 2-1
DESCRIPTION .............................................. 3-1
Left view ...................................................... 3-1
Right view.................................................... 3-1
Controls and instruments ............................ 3-2
INSTRUMENT AND
CONTROL FUNCTIONS................................ 4-1
Main switch ................................................ 4-1
Indicator lights and warning light ................ 4-2
Multifunction display ................................... 4-4
Handlebar switches .................................... 4-6
Throttle lever ............................................ 4-12
Speed limiter .............................................4-13
Front brake lever .......................................4-14
Brake pedal and rear brake lever .............4-14
Drive select lever ......................................4-15
Recoil starter .............................................4-15
Fuel tank cap ............................................4-16
Fuel ...........................................................4-16
Fuel cock ..................................................4-18
Starter (choke) ..........................................4-19
Seat ..........................................................4-20
Storage compartment ...............................4-21
Front carrier ..............................................4-22
Rear carrier ...............................................4-22
Adjusting the front and
rear shock absorber assemblies .............4-22
Auxiliary DC jack .......................................4-23
PRE-OPERATION CHECKS ..........................5-1
Pre-operation check list ..............................5-1
Fuel .............................................................5-4
Engine oil ....................................................5-4
Final gear oil ...............................................5-4
Differential gear oil ......................................5-4
Coolant .......................................................5-4
Front and rear brakes .................................5-5
Throttle lever ...............................................5-6
Tires ............................................................5-7
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

Measuring the tire pressure ....................... 5-8
Tire wear limit ............................................. 5-9
Chassis fasteners ....................................... 5-9
Instruments, lights and switches ................ 5-9
OPERATION .................................................. 6-1
Starting a cold engine ................................ 6-1
Starting a warm engine .............................. 6-3
Operating the drive select lever and
driving in reverse ...................................... 6-3
Engine break-in .......................................... 6-5
Parking ....................................................... 6-6
Parking on a slope ..................................... 6-6
Accessories and loading ............................ 6-7
RIDING YOUR ATV ...................................... 7-1
GETTING TO KNOW YOUR ATV............... 7-2
RIDE WITH CARE AND
GOOD JUDGEMENT................................ 7-3
BE CAREFUL WHERE YOU RIDE........... 7-13
TURNING YOUR ATV .............................. 7-19
CLIMBING UPHILL ................................... 7-21
RIDING DOWNHILL.................................. 7-25
CROSSING A SLOPE............................... 7-27
CROSSING THROUGH
SHALLOW WATER................................. 7-29
RIDING OVER ROUGH TERRAIN ........... 7-31
SLIDING AND SKIDDING .........................7-32
WHAT TO DO IF........................................7-33
WHAT TO DO............................................7-33
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
Removing and installing panels ..................8-9
Checking the spark plug ...........................8-16
Engine oil and oil filter cartridge ................8-18
Final gear oil .............................................8-22
Differential gear oil ....................................8-24
Coolant .....................................................8-26
Cleaning the air filter element ...................8-31
Cleaning the spark arrester ......................8-34
V-belt cooling duct check hose .................8-36
V-belt case drain plug ...............................8-36
Adjusting the carburetor ............................8-37
Adjusting the engine idling speed .............8-37
Adjusting the throttle cable free play .........8-38
Valve clearance ........................................8-39
Adjusting the drive select lever
safety system cable ................................8-39
U23D10E0.book Page 2 Wednesday, March 14, 2007 1:50 PM

Checking the front and rear brake pads ... 8-39
Checking the brake fluid level .................. 8-40
Changing the brake fluid .......................... 8-42
Checking the front brake lever
free play ................................................. 8-42
Adjusting the rear brake lever free play
and checking the brake pedal position ... 8-43
Axle boots ................................................ 8-45
Brake light switches ................................. 8-46
Checking and lubricating the cables ........ 8-46
Checking and lubricating
the front and rear brake levers ............... 8-47
Checking and
lubricating the brake pedal ..................... 8-48
Checking the wheel hub bearings ............ 8-48
Checking the stabilizer bushes ................ 8-48
Lubricating the rear knuckle pivots ........... 8-48
Lubricating the steering shaft ................... 8-49
Battery ...................................................... 8-49
Replacing a fuse ...................................... 8-51
Replacing a headlight bulb ....................... 8-52
Adjusting a headlight beam ...................... 8-54
Replacing the tail/brake light bulb ............ 8-55
Removing a wheel .................................... 8-55
Installing a wheel ...................................... 8-56
Troubleshooting ....................................... 8-57
Troubleshooting charts ............................. 8-59
CLEANING AND STORAGE ..........................9-1
Cleaning ......................................................9-1
Storage .......................................................9-2
SPECIFICATIONS .......................................10-1
CONSUMER INFORMATION.......................11-1
Identification numbers ...............................11-1
Noise regulation ........................................11-3
Maintenance record ..................................11-4
YAMAHA MOTOR CORPORATION,
U.S.A. ATV LIMITED WARRANTY .........11-5
YAMAHA EXTENDED SERVICE
(Y.E.S.) ...................................................11-7
U23D10E0.book Page 3 Wednesday, March 14, 2007 1:50 PM

1-1
1
EBU17430
SAFETY INFORMATION
EBU17482
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. Take a Training Course. Beginners
should receive training from a certified instruc-
tor. Contact an authorized ATV dealer or call 1-
800-887-2887 to find out about the training
courses nearest you.
●Always follow the age recommendation:
–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 public street, road
or highway, even a dirt or gravel one.
●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 while
operating this ATV.
●Never operate at speeds too fast for your skills
or the riding conditions. Always go at a speed
that is proper for the terrain, visibility, operating
conditions, and your experience.
●Never attempt wheelies, jumps, or other stunts.
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

1-2
1
●Always inspect your ATV each time you use it to
make sure it is in safe operating condition. Al-
ways follow the inspection and maintenance
procedures and schedules described in this
manual.
●Always keep both hands on the handlebars and
both feet on the footboards of the ATV during
operation.
●Always go slowly and be extra careful when op-
erating on unfamiliar terrain. Always be alert to
changing terrain conditions when operating the
ATV.
●Never operate on excessively rough, slippery or
loose terrain until you have learned and prac-
ticed the skills necessary to control the ATV on
such terrain. Always be especially cautious on
these kinds of terrain.
●Always follow proper procedures for turning as
described in this manual. Practice turning at low
speeds before attempting to turn at faster
speeds and never turn at excessive speeds.
●Never operate the ATV on hills too steep for the
ATV or for your abilities. Practice on smaller hills
before attempting larger hills.
●Always follow proper procedures for climbing
hills as described in this manual. Check the ter-
rain carefully before you start up any hill. Never
climb hills with excessively slippery or loose sur-
faces. Shift your weight forward. Never open the
throttle suddenly. Never go over the top of a hill
at high speed.
●Always follow proper procedures for going down
hills and for braking on hills as described in this
manual. Check the terrain carefully before you
start down any hill. Shift your weight backward.
Never go down a hill at high speed. Avoid going
down a hill at an angle that would cause the ve-
hicle to lean sharply to one side. Go straight
down the hill where possible.
●Always follow proper procedures for crossing
the side of a hill as described in this manual.
Avoid hills with excessively slippery or loose sur-
faces. Shift your weight to the uphill side of the
ATV. Never attempt to turn the ATV around on
any hill until you have mastered the turning tech-
nique 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 range and maintain a
U23D10E0.book Page 2 Wednesday, March 14, 2007 1:50 PM

1-3
1
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 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 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.
FOR MORE INFORMATION ABOUT ATV SAFE-
TY, call the Consumer Products Safety Commis-
sion at 1-800-638-2772, or the ATV Distributor’s
Safety Hotline at 1-800-852-5344.
U23D10E0.book Page 3 Wednesday, March 14, 2007 1:50 PM

1-4
1
WARNING
EWB00021
WARNING
EWB00030
POTENTIAL HAZARD
Improper handling of gasoline.
WHAT CAN HAPPEN
Gasoline can catch fire and you could be
burned.
HOW TO AVOID THE HAZARD
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 refuel while smoking, or in the vicinity
of sparks, open flames, or other sources of
ignition such as the pilot lights of water
heaters and clothes dryers.
When transporting the ATV in another vehi-
cle, be sure it is kept upright and that the
fuel cock is in the “OFF”position. Other-
wise, fuel may leak out of the carburetor or
fuel tank.
WHAT CAN HAPPEN
Gasoline is poisonous and can cause inju-
ries.
HOW TO AVOID THE HAZARD
If you should swallow some gasoline or in-
hale a lot of gasoline vapor, or get some gas-
oline in your eyes, seek medical help
immediately. If gasoline spills on your skin,
wash with soap and water. If gasoline spills
on your clothing, change your clothes.
POTENTIAL HAZARD
Starting or running the engine in a closed ar-
ea.
U23D10E0.book Page 4 Wednesday, March 14, 2007 1:50 PM

1-5
1
WHAT CAN HAPPEN
Exhaust fumes are poisonous and may
cause loss of consciousness and death
within a short time.
HOW TO AVOID THE HAZARD
Always operate your ATV in an area with ad-
equate ventilation.
U23D10E0.book Page 5 Wednesday, March 14, 2007 1:50 PM

2-1
2
EBU17660
LOCATION OF THE WARNING AND SPECIFICATION LABELS
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

2-2
2
EBU17670
Read and understand all of the labels on your ATV. These labels contain important information for safe and
proper operation.
Never remove any labels from your ATV. If a label becomes difficult to read or comes off, request a replace-
ment label from your Yamaha dealer.
U23D10E0.book Page 2 Wednesday, March 14, 2007 1:50 PM

2-3
2
U23D10E0.book Page 3 Wednesday, March 14, 2007 1:50 PM

2-4
2
U23D10E0.book Page 4 Wednesday, March 14, 2007 1:50 PM

3-1
3
EBU17680
DESCRIPTION
EBU17690
Left view
EBU17700
Right view
1. Radiator cap
2. Fuel tank cap
3. Fuel cock
4. Oil filter cartridge
5. Throttle stop screw
6. Fuses
7. Engine oil filler cap
8. Recoil starter
9. Coolant reservoir
10.Drive select lever box check hose
11.V-belt cooling duct check hose
1. Rear shock absorber assembly spring preload adjusting
ring
2. Spark arrester
3. Storage compartment and tool kit
4. Battery
5. Air filter case
6. Spark plug
7. Front brake fluid reservoir
8. Front shock absorber assembly spring preload adjusting
ring
9. Rear brake fluid reservoir
10.Brake pedal
11.V-belt case drain plug
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM

3-2
3
EBU17712
Controls and instruments NOTE:
The ATV you have purchased may differ slightly
from the figures shown in this manual.
1. Drive select lever
2. Rear brake lever
3. Handlebar switches
4. Starter (choke)
5. Multifunction display
6. Main switch
7. On-Command four-wheel-drive/differential gear lock
switch
8. Throttle lever
9. Front brake lever
10.Auxiliary DC jack
U23D10E0.book Page 2 Wednesday, March 14, 2007 1:50 PM

4-1
4
EBU17720
INSTRUMENT AND CONTROL FUNCTIONS
WARNING
EWB00010
Indicates a potential hazard that could result in
serious injury or death.
EBU17760
Main switch
The positions of the main switch are as follows:
ON
All electrical systems are supplied with power. The
headlights and taillight come on when the light
switch is on, and the engine can be started. The
key cannot be removed.
OFF
All electrical systems are off. The key can be re-
moved.
1. Main switch
U23D10E0.book Page 1 Wednesday, March 14, 2007 1:50 PM