engine YAMAHA YFM50R 2007 Owners Manual

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 light ............................................. 4-1
Handlebar switches ................................... 4-2
Engine stop switch with lanyard ................ 4-2
Throttle lever ............................................. 4-4
Speed limiter ............................................. 4-5
Front brake lever ....................................... 4-6
Rear brake lever ........................................ 4-6
Parking brake ............................................ 4-6
Drive select lever ....................................... 4-7
Fuel tank cap ............................................. 4-7
Fuel ........................................................... 4-8
Fuel cock ................................................... 4-9Choke ...................................................... 4-10
Seat ......................................................... 4-11
PRE-OPERATION CHECKS ..........................5-1
Pre-operation check list ............................. 5-1
Fuel ............................................................ 5-3
Engine oil ................................................... 5-3
Final gear 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 ...................................... 5-6
Instruments, lights and switches ................ 5-6
Battery ....................................................... 5-6
OPERATION...................................................6-1
Starting a cold engine ................................ 6-1
Starting a warm engine .............................. 6-3
Shifting ....................................................... 6-3
Engine break-in .......................................... 6-5
Parking ....................................................... 6-5
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 ...........................................7-2
BE CAREFUL WHERE YOU RIDE ............ 7-8
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 .......... 7-19
SLIDING AND SKIDDING ........................ 7-20
WHAT TO DO IF... ................................... 7-21
WHAT TO DO... ....................................... 7-21
PERIODIC MAINTENANCE AND MINOR
REPAIR .......................................................... 8-1
Owner’s manual and tool kit ...................... 8-1
Periodic maintenance and lubrication
chart ........................................................ 8-3
Checking the spark plug ............................ 8-7
Engine oil .................................................. 8-8
Final gear oil ............................................ 8-11
Cleaning the air filter element ................. 8-12
Cleaning the spark arrester ..................... 8-15
Adjusting the carburetor .......................... 8-17
Adjusting the engine idling speed ........... 8-17
Checking the throttle cable free play ....... 8-18Valve clearance ....................................... 8-18
Checking the front and rear brake
shoes .....................................................8-19
Adjusting the front brake lever free
play ........................................................8-20
Adjusting the rear brake lever free play ... 8-22
Checking and lubricating the cables ........ 8-23
Checking and lubricating the front and
rear brake levers ....................................8-24
Checking the wheel bearings ................... 8-24
Lubricating the knuckle shafts ................. 8-24
Lubricating the steering shaft ................... 8-25
Battery ..................................................... 8-25
Replacing the fuse ................................... 8-28
Removing a wheel ................................... 8-28
Installing a wheel ..................................... 8-29
Troubleshooting ....................................... 8-31
Troubleshooting chart .............................. 8-32
CLEANING AND STORAGE ..........................9-1
Cleaning ..................................................... 9-1
Storage ...................................................... 9-2
SPECIFICATIONS .......................................10-1
CONSUMER INFORMATION.......................11-1
Identification numbers .............................. 11-1

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EBU17430
SAFETY INFORMATION

SAFETY INFORMATION

EBU17651
AN ATV IS NOT A TOY AND CAN BE HAZARD-
OUS TO OPERATE.

An ATV handles differently
from other vehicles, including motorcycles and
cars. A collision or rollover can occur quickly, even
during routine maneuvers such as turning and
riding on hills or over obstacles, if you fail to take
proper precautions.
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 6 years old should never operate
an ATV with engine size greater than 50 cc.
– 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 paved streets.

Never operate an ATV on any paved street,
paved road or motorway.

Watch 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.

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.

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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. 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 afterleaving 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.
TEACHING YOUR CHILD TO OPERATE THE
ATV
WARNING

EWB00080
Never let your child ride an ATV without close
adult supervision (a child under 6 should not
ride this ATV even with adult supervision).
Promptly correct your child if he or she begins
to ride beyond his or her abilities and, if neces-
sary, intervene by pulling the cord (lanyard) to
stop the engine.
If the child rides beyond his or her abilities, or

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rides in terrain that is too difficult, he or she
may lose control of the ATV, causing an acci-
dent.
Introduce new riding areas slowly and make
sure the riding area matches your child’s skill
level.
You must make the commitment to your child’s
proper use of the ATV. Your child must rely upon
you to be sure he or she has the development,
proper training, and proper equipment, as well as
an appropriately sized ATV and an appropriate
riding area.
Be sure your child is ready to learn how to ride
As a parent, your first step is to decide when your
child has the strength, skills, and judgment to learn
how to operate an ATV safely. Re-evaluate your
child’s readiness before every use; a child who is
too tired or distracted should not be allowed to op-
erate the ATV.
Be sure your child is properly trained
Your child should take a certified training course.
Training will continue with you as the instructor, so
you should be sure you thoroughly understand
proper riding techniques before continuing to in-struct your child. Go through this Owner’s Manual
page by page with your child and be sure he or she
understands how to operate the ATV properly.
Be sure your child is wearing all the proper
safety equipment
Your child must always wear an approved motor-
cycle helmet that fits properly. Your child should
also wear the safety equipment described in the
Riding Your ATV section of this manual.
Choose an appropriate riding area
Select an area appropriate for your child to learn to
ride. (See page 7-8.) Follow the instructions in the
Riding Your ATV section of this manual. Choose a
large, flat, unpaved road or area that is free of ob-
stacles and away from other vehicles.
Supervise every use of the ATV
Because an adult must supervise every ATV oper-
ator under age 16, you should closely watch your
child every time he or she uses the ATV. Be ready
to intervene immediately if the child is not operat-
ing according to your guidelines. This ATV is fitted
with an engine stop switch cord (lanyard) device
that will let you stop the engine remotely as you
walk behind the vehicle.

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ENGINE STOP SWITCH CORD
This model has an engine stop switch cord (lan-
yard) designed for use by an adult supervising the
child operating the ATV. When using the engine
stop switch cord, be sure the speed limiter on the
handlebar is adjusted to limit the ATV to a walking
speed. (See page 4-5.)
1. Push the clip on the end of the engine stop
switch cord under the engine shut-off switch
(black button).
2. Put your fingers in the loop at the other end of
the cord.
3. As your child is riding, walk behind the ATV,
closely watching his or her actions as well as
the path ahead.
4. If there is a potential hazard ahead or if your
child is not riding correctly, pull firmly on the
cord (lanyard) to stop the engine. Because the
ATV will continue to roll for some distance, al-
low extra time and distance to pull the cord be-
fore a potentially hazardous situation might be
encountered.
When your child has developed sufficient skill to no
longer need you to follow with the cord, the cord
can be stowed under the seat of the ATV. Howev-
er, you must still closely supervise your child at alltimes during ATV operation.NOTE:

The ATV will not start without the clip in place. Be
sure to remove the cord and store it in a safe place
to prevent operation of the ATV when you are not
around to supervise.WARNING
EWB00061

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
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,

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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

EWB00070
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.

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EBU17680
DESCRIPTION
EBU17690
Left view
EBU17700
Right view
1. Fuel cock
2. Fuse
3. Engine stop switch with cord (lanyard)
4. Footboard
5. Drive select lever
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1. Spark arrester
2. Seat
3. Footboard
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EBU17730
INSTRUMENT AND CONTROL FUNCTIONS
EBU17740
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.

EBU17780
Indicator light
EBU17860
Neutral indicator light “”
This indicator light comes on when the transmis-
sion is in the neutral position.
1. Main switch
OFF ON
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1. Neutral indicator light “N”
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EBU18060
Handlebar switches
EBU18070
Engine stop switch “ENG. STOP”
Set this switch to “RUN” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this switch
to stop the engine in an emergency situation. The
engine will not start or run when this switch is set
to “OFF”.
EBU18090
Start switch “START”
Push this switch to crank the engine with the start-
er.CAUTION:

ECB00050
See the starting instructions on page 6-1 prior
to starting the engine.
EBU18260
Engine stop switch with lanyard
The clip must be attached to the engine stop
switch for the engine to run.
1. Engine stop switch “ENG. STOP”
2. Start switch “START”
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