engine YAMAHA BRUIN 250 2005 Owner's Guide

7-7
Riding your ATV requires skills acquired
through practice over a period of time.
Take the time to learn the basic techniques well
before attempting more difficult maneuvers.
Not recommended for children under 16 years
of age.
WARNING
_ A child under 16 should never operate an ATV
with engine size greater than 90cc. Use by chil-
dren of ATVs that are not recommended for
their age can lead to severe injury or death of
the child. _
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7-35
Select a large, flat area off-road to become familiar
with your ATV. Make sure that this area is free of
obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain. Always avoid riding on paved
surfaces: the ATV is designed for off-road use
only, and handling maneuvers are more difficult to
perform on pavement.
Set the parking brake and follow the instruction on
page 6-3 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. As you
get on the ATV, be sure not to accidentally move
the shift pedal. Remember that the engine and ex-
haust pipe will be hot when riding and afterwards;
do not allow skin or clothing to come in contact
with these components.
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7-37
With the engine idling, lift the shift pedal to the 1st
gear position and then release the parking brake.
Apply the throttle slowly and smoothly. The centrif-
ugal clutch will engage and you will start to accel-
erate. Once the ATV has attained adequate
speed, release the throttle and lift the shift pedal to
the 2nd gear position. Release the shift pedal and
apply the throttle smoothly. Use this same proce-
dure as you move into the higher gears. Be sure to
coordinate the use of the throttle and shift pedal
properly. If the throttle is applied too abruptly or if
the throttle is not released during shifting, or if the
shift pedal is not released before applying the
throttle, the front wheels may lift off the ground re-
sulting in a loss of directional control. Avoid higher
speeds until you are thoroughly familiar with the
operation of your ATV.CAUTION:_ Do not shift gears without releasing the throt-
tle. Damage to the engine or drive train may oc-
cur. _
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7-39
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. As
you slow down, shift to a lower gear. Be sure that
the engine has sufficiently slowed before engaging
a lower gear. Improper use of the brakes or shift-
ing can cause the tires to lose traction, reducing
control and increasing the possibility of an acci-
dent.
WARNING
_ Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too high
could cause the wheels to stop rotating. _
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7-57
RIDING DOWNHILL
When riding your ATV downhill, shift your weight
as far to the rear and uphill side of the ATV as pos-
sible. Move back on the seat and sit with your
arms straight. Choose a low gear which will allow
the engine compression to do most of the braking
for you. Improper braking may cause a loss of trac-
tion.
Use caution while descending a hill with loose or
slippery surfaces. Braking ability and traction may
be adversely affected by these surfaces. Improper
braking may also cause a loss of traction.
Whenever possible, ride your ATV straight down-
hill. Avoid sharp angles which could allow the ATV
to tip or roll over. Carefully choose your path and
ride no faster than you will be able to react to ob-
stacles which may appear.
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8-1
EBU00516
1-PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
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 can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service.
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8-7
EBU02621
PERIODIC MAINTENANCE/LUBRICATION
NOTE:_

For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.


For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance intervals. How-
ever, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance intervals should be
followed.
_
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
Valves*Check valve clearance.
Adjust if necessary.
Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check starter (choke) operation.
Adjust engine idling speed.Cylinder head breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Tighten if necessary.
Replace gasket(s) if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace (Warm engine before draining).Engine oil filter element
Clean.U1P060.book Page 7 Monday, August 2, 2004 12:19 PM

8-8
Engine oil strainer
Clean.Final gear oilCheck oil level/oil leakage.
Replace.Front brake*Check operation/fluid leakage/see NOTE page 8-9.
Correct if necessary.Rear brake*Check operation.
Adjust if necessary.Select lever safety
system cable*Check operation.
Adjust if necessary.Clutch*Check operation.
Adjust if necessary.Wheels*Check balance/damage/runout.
Repair if necessary.Wheel bearings*Check bearing assemblies for looseness/damage.
Replace if damaged.Front and rear
suspension*Check operation.
Correct if necessary.Steering system*Check operation./Replace if damaged.
Check toe-in./Adjust if necessary.Steering shaft*Lubricate every 6 months with lithium-soap-based grease
(all-purpose grease).Fittings and fasteners*Check all chassis fittings and fasteners.
Correct if necessary.
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
U1P060.book Page 8 Monday, August 2, 2004 12:19 PM

8-17 1. Engine oil filler cap
2. Dipstick
3. Maximum level mark
4. Minimum level mark
1. Bouchon de remplissage d’huile de moteur
2. Jauge
3. Repère de niveau maximum
4. Repère de niveau minimum
1. Tapa del filtro de aceite de motor
2. Varilla de nivel de aceite
3. Marca de nivel máximo
4. Marca de nivel mínimo
EBU11005
Engine oil and oil filter element
The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter element cleaned at the intervals speci-
fied in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Warm up the engine for several minutes, and
then turn it off.
3. Wait at least ten minutes until the oil level set-
tles before checking.
4. Remove the engine oil filler cap, and then
wipe the dipstick off with a clean rag. Insert
the dipstick in the filler hole (without screwing
it in), and then remove it again to check the oil
level.NOTE:_

Be sure to wait at least ten minutes until the
oil level settles before checking.


The oil level should be between the minimum
and maximum level marks.
_
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8-19 1. Engine oil drain bolt 2. O-ring
3. Compression spring 4. Engine oil strainer
1. Boulon de vidange de l’huile moteur
2. Joint torique
3. Ressort de compression
4. Crépine à huile de moteur
1. Perno de drenaje del aceite de motor
2. Junta tórica
3. Muelle de compresión
4. Tamiz de aceite de motor
5. If the engine oil is at or below the minimum
level mark, add sufficient oil of the recom-
mended type to raise it to the correct level.CAUTION:_ Make sure that no foreign material enters the
crankcase. _6. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
To change the engine oil (with or without oil fil-
ter element cleaning)
1. Place the ATV on a level surface.
2. Warm up the engine for several minutes, and
then turn it off.
3. Place a container under the engine to collect
the used oil.
4. Remove the engine oil filler cap, and then re-
move the engine oil drain bolt to drain the oil
from the crankcase.
U1P060.book Page 19 Monday, August 2, 2004 12:19 PM