engine YAMAHA BRUIN 350 2WD 2006 Owner's Guide

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, and turning tech-
niques in this area before trying more difficult ter-
rain. Always avoid riding on paved surfaces: the
ATV is designed for off-road use only, and han-
dling maneuvers are more difficult to perform on
pavement.
Set the parking brake and follow the instructions
on page 6-3 to start the engine. Once it has
warmed up you are ready to begin riding your
ATV. Remember that the engine and exhaust pipe
will be hot when riding and afterwards; do not al-
low skin or clothing to come in contact with these
components.
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7-37
With the engine idling, return the starter (choke) to
the closed position and shift the drive select lever
into the forward position, then release the parking
brake. Apply the throttle slowly and smoothly. The
centrifugal clutch will engage and you will start to
accelerate. If the throttle is applied too abruptly,
the front wheels may lift off the ground resulting in
a loss of directional control. Avoid higher speeds
until you are thoroughly familiar with the operation
of your ATV.
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. Im-
proper use of the brakes can cause the tires to
lose traction, reducing control and increasing the
possibility of an accident.
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8-1
EBU00516
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.
EE.book Page 1 Friday, April 1, 2005 9:57 AM

8-8
Engine oil
Replace. (Warm engine before draining.)Engine oil filter cartridge
Replace.Final gear oilCheck oil level/oil leakage.
Replace every 12 months.Front brake*Check operation/fluid leakage. (See NOTE page 8-9.)
Correct if necessary.Rear brakeCheck operation.
Adjust if necessary.Select lever safety system
cable*Check operation.
Adjust if necessary.V-belt*Check operation.
Check for cracks or damage.Wheels*Check balance/damage/runout.
Repair if necessary.Wheel bearing*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.Drive shaft universal
joint*Lubricate with lithium-soap-based grease.Fittings and fasteners*Check all chassis fittings and fasteners.
Correct if necessary.Lights and switches*Check operation.
Adjust headlight beams.
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
EE.book Page 8 Friday, April 1, 2005 9:57 AM

8-21 1. Engine oil filler cap
1. Bouchon de remplissage d’huile de moteur
1. Tapa de relleno de aceite de motor
1. Maximum level mark 2. Minimum level mark
1. Repère de niveau maximum 2. Repère de niveau minimum
1. Marca de nivel máximo 2. Marca de nivel mínimo
EBU14540
Engine oil and oil filter cartridge
The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter cartridge replaced at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Wait a few minutes until the oil settles.
4. Remove the engine oil filler cap and wipe off
the dipstick with a clean rag.
5. Insert the dipstick in the oil filler hole (without
screwing it in), and then remove it again to
check the oil level.NOTE:_ The engine oil should be between the minimum
and maximum level marks. _
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8-23 1. Engine oil drain bolt
1. Boulon de vidange de l’huile
1. Perno de drenaje del aceite de motor
6. 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.
7. Insert the dipstick into the oil filler hole, and
then tighten the oil filler cap.
To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Start the engine, warm it up for several min-
utes, and then turn it off.
2. Place an oil pan under the engine to collect
the used oil, and then remove the engine oil
filler cap.
3. Remove the engine oil drain bolt to drain the
oil from the crankcase.
EE.book Page 23 Friday, April 1, 2005 9:57 AM

8-27 1. O-ring
1. Joint torique
1. Junta tórica
1. Torque wrench
1. Clé dynamométrique
1. Llave de apriete
5. Apply a light coat of engine oil to the O-ring of
the new oil filter cartridge.NOTE:_ Make sure the O-ring is seated properly. _6. Install the new oil filter cartridge with an oil fil-
ter wrench, and then tighten it to the specified
torque with a torque wrench.
7. Install the engine oil drain bolt, and then tight-
en it to the specified torque. Tightening torque:
Oil filter cartridge:
17 Nm (1.7 m·kgf)
Tightening torque:
Engine oil drain bolt:
23 Nm (2.3 m·kgf)
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8-29
8. Add the specified amount of recommended
engine oil, and then install the engine oil filler
cap and tighten it.CAUTION:_

In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of
“CD” or oils of a higher quality than spec-
ified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or higher.


Make sure that no foreign material enters
the crankcase.
_
Recommended engine oil:
See page 10-2.
Oil quantity:
Without oil filter cartridge replacement:
2.2 L
With oil filter cartridge replacement:
2.3 L
EE.book Page 29 Friday, April 1, 2005 9:57 AM

8-31 1. Final gear oil
2. Final gear oil filler bolt
3. Correct oil level
1. Huile de transmission finale
2. Boulon de remplissage d’huile du carter de transmission finale
3. Niveau d’huile correct
1. Aceite de la transmisión final
2. Perno del orificio de llenado de aceite de la transmisión final
3. Nivel de aceite correcto
9. Start the engine and warm it up for several
minutes. While warming up, check for oil
leakage. If oil leakage is found, turn the en-
gine off immediately and check for the cause.
10. Turn the engine off, and then check the oil
level and correct it if necessary.
EBU11453
Final gear oil
Checking the final gear oil
1. Place the ATV on a level surface.
2. Remove the oil filler bolt, and then check the
oil level in the final gear case.NOTE:_ The oil level should be at the brim of the filler hole. _3. If the oil is below the brim of the filler hole,
add sufficient oil of the recommended type to
raise it to the correct level.CAUTION:_ Be sure no foreign material enters the final
gear case. _
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8-41
Inspection
The spark plug is an important engine component
and is easy to inspect. The condition of the spark
plug can indicate the condition of the engine.
The ideal color on the white insulator around the
center electrode is a medium-to-light tan color for
an ATV that is being ridden normally.
Do not attempt to diagnose such problems your-
self.
Instead, take the ATV to a Yamaha dealer. You
should periodically remove and inspect the spark
plug because heat and deposits will cause the
spark plug to slowly break down and erode. If elec-
trode erosion becomes excessive, or if carbon and
other deposits are excessive, you should replace
the spark plug with the specified plug.
Specified spark plug:
DR8EA (NGK)
EE.book Page 41 Friday, April 1, 2005 9:57 AM