2006 YAMAHA BRUIN 250 engine

8-21 1. Footboard 2. Bolt (× 8)
1. Repose-pied 2. Boulon (× 8)
1. Plataforma para los pies 2. Perno (× 8)
1. Adjusting nut (brake rod)
1.Écrou de réglage (tringle de frein)
1. Tuerca de ajuste (barra del freno)
CAUTION:_ When removing the engine oil drain bolt, the
compression spring, oil strainer and O-ring
will fall out. Take care not to lose these parts. _NOTE:_ Skip steps 5–11 if the oil filter element is not being
cleaned. _5. Remove the footboard by removing the bolts.
6. Fully loosen the brake pedal free play adjust-
ing nut, push the brake pedal downward, and
then remove the oil filter element cover bolts.
EE.book Page 21 Friday, May 27, 2005 5:00 PM

8-23 1. Oil filter element cover 2. Adjusting nut (× 3)
1. Couvercle de l’élément du filtre à huile
2.Écrou de réglage (× 3)
1. Cubierta del elemento del filtro de aceite
2. Tuerca de ajuste (× 3)
1. Engine oil filter element 2. O-ring
1.Élément du filtre à huile de moteur 2. Joint torique
1. Elemento del filtro de aceite de motor
2. Junta tórica
7. Remove the oil filter element cover and oil fil-
ter element.NOTE:_ To remove or install the oil filter element cover and
oil filter element, move the select lever safety sys-
tem cable away from the cover. _CAUTION:_ Do not loosen the adjusting nuts shown when
removing the oil filter element cover or oil filter
element. _8. Clean the oil strainer and oil filter element
with solvent.
9. Check the O-ring for damage and replace it if
necessary.NOTE:_ Make sure the O-ring is seated properly. _
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8-25
10. Install the oil filter element.
11. Install the oil filter element cover by installing
the bolts, and then tightening them to the
specified torque.
12. Install the oil strainer, compression spring,
O-ring and engine oil drain bolt, and then
tighten the engine oil drain bolt to the speci-
fied torque.CAUTION:_ Before installing the engine oil drain bolt, be
sure to install the O-ring, compression spring
and oil strainer. _
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf)
Tightening torque:
Engine oil drain bolt:
43 Nm (4.3 m·kgf)
EE.book Page 25 Friday, May 27, 2005 5:00 PM

8-27
13. Add the specified amount of the recommend-
ed engine oil, then install and tighten the en-
gine oil filler cap.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 specified. 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 element removal:
1.50 L
With oil filter element removal:
1.60 L
EE.book Page 27 Friday, May 27, 2005 5:00 PM

8-29 1. Bolt A (× 6) 2. Bolt B (× 2)
1. Boulon A (× 6) 2. Boulon B (× 2)
1. Perno A (× 6) 2. Perno B (× 2)
14. Start the engine, and then let it idle for seve-
ral minutes while checking it for oil leakage. If
oil is leaking, immediately turn the engine off
and check for the cause.
15. Turn the engine off, and then check the oil
level and correct it if necessary.
16. Install the footboard by installing the bolts,
and then tightening them to the specified
torque.
17. Adjust the brake pedal free play. (See page
8-67.) Tightening torque:
Footboard bolt A:
3.8 Nm (0.38 m·kgf)
Footboard bolt B:
6.5 Nm (0.65 m·kgf)
EE.book Page 29 Friday, May 27, 2005 5:00 PM

8-37 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
1. Spark plug wrench
1. Clé à bougie
1. Llave de bujía
EBU14550
Spark plug inspection
Removal
1. Remove the spark plug cap.
2. Use the spark plug wrench in the owner’s tool
kit to remove the spark plug as shown.
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.
EE.book Page 37 Friday, May 27, 2005 5:00 PM

8-45 1. Air filter element
1.Élément du filtre à air
1. Elemento del filtro de aire
1. Air filter element 2. Foam cover
1.Élément du filtre à air 2. Cache en mousse
1. Elemento del filtro de aire 2. Forro de espuma
3. Pull the air filter element out.
4. Remove the foam cover from the air filter ele-
ment.
5. Wash the foam cover gently but thoroughly in
water or solvent.
WARNING
_ When using solvent to clean the foam cover,
always use parts cleaning solvent. Never use
low flash point solvents or gasoline to clean
the foam cover because the engine could
catch fire or explode. _6. Squeeze the excess solvent out of the foam
cover and let it dry.CAUTION:_

Do not twist the foam cover when squeez-
ing it.


Do not apply oil to the foam cover.
_
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8-47
7. Tap the air filter element lightly to remove
most of the dust and dirt. Blow out the re-
maining dirt with compressed air as shown. If
the air filter element is damaged, replace it.NOTE:_ Check the foam cover for damage and replace it if
necessary. _8. Install the foam cover onto the air filter ele-
ment.
9. Install the air filter element.
10. Install the air filter case cover by fastening the
holders.
11. Install the seat.NOTE:_ The air filter element should be cleaned every 20–
40 hours. It should be cleaned more often if the
ATV is operated in extremely dusty areas. Each
time air filter element maintenance is performed,
check the air inlet to the air filter case for obstruc-
tions. Check the air filter element rubber joint to the
carburetor and manifold fittings for an airtight seal.
Tighten all fittings securely to avoid the possibility
of unfiltered air entering the engine. _
EE.book Page 47 Friday, May 27, 2005 5:00 PM