all YAMAHA BRUIN 250 2005 Owners Manual

8-41
NOTE:_ If a torque wrench is not available when you are in-
stalling a spark plug, a good estimate of the correct
torque is 1/4 to 1/2 turn past finger tight. Have the
spark plug tightened to the specified torque as
soon as possible. _4. Install the spark plug cap.
U1P060.book Page 41 Monday, August 2, 2004 12:19 PM

8-43 1. Air filter case check hose
1. Flexible de contrôle du boîtier du filtre à air
1. Manguito de retención de la caja del filtro de aire
1. Air filter case cover 2. Holder (× 3)
1. Couvercle du boîtier de filtre à air 2. Support (× 3)
1. Tapa de la caja del filtro de aire 2. Soporte (× 3)
EBU10862
Air filter element cleaningNOTE:_ There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case. _1. Remove the seat. (See page 4-27 for seat re-
moval and installation procedures.)
2. Remove the air filter case cover by unhook-
ing the holders.
U1P060.book Page 43 Monday, August 2, 2004 12:19 PM

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. _
U1P060.book Page 47 Monday, August 2, 2004 12:19 PM

8-49
CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the air filter element will affect carburetor
jetting with subsequent poor performance and
possible engine overheating. _
EBU00296
Carburetor adjustment
The carburetor is a vital part of the engine and re-
quires very sophisticated adjustment. Most adjust-
ing should be left to a Yamaha dealer who has the
professional knowledge and experience to do so.
However, the idling speed may be performed by
the owner as a part of the usual maintenance rou-
tine.CAUTION:
The carburetor was set at the Yamaha factory
after many tests. If the settings are disturbed
by someone without sufficient technical
knowledge, poor engine performance and
damage may result.
U1P060.book Page 49 Monday, August 2, 2004 12:19 PM

8-51 1. Throttle stop screw
1. Vis d’arrêt de l’accélérateur
1. Tornillo de tope del acelerador
EBU13020
Idle speed adjustmentNOTE:_ A diagnostic tachometer must be used for this pro-
cedure. _1. Start the engine and warm it up for a few min-
utes at approximately 1,000 to 2,000 r/min.
Occasionally rev the engine to 4,000 to
5,000 r/min. The engine is warm when it
quickly responds to the throttle.
2. Connect the tachometer to the spark plug
lead, and then set the idle to the specified
idling speed by adjusting the throttle stop
screw. Turn the screw in direction
a to in-
crease the engine speed, and in direction
b
to decrease the engine speed.
Specified idle speed:
1,400–1,500 r/min
U1P060.book Page 51 Monday, August 2, 2004 12:19 PM

8-55 1. Brake pad (× 2) a. Brake pad thickness
1. Plaquette de frein (× 2) a.Épaisseur de plaquette de frein
1. Pastilla del freno (× 2) a. Espesor de la pastilla del freno
EBU03050
Select lever safety system cable adjustment
The select lever safety system cable stretches
with use, resulting in improper function. To prevent
this, the cable must be adjusted regularly. This ad-
justment, however, should be left to a Yamaha
dealer.
EBU13770
Front brake pad check
Check the brake pads for damage and wear. If a
brake pad thickness is less than 1.0 mm, have a
Yamaha dealer replace the pads as a set.NOTE:_ The wheels need to be removed to check the
brake pads. (See pages 8-81–8-83 for removal
and installation procedures.) _
U1P060.book Page 55 Monday, August 2, 2004 12:19 PM

8-56
FBU03050
Réglage du câble de sécurité du levier de présélection
Le câble de sécurité du levier de présélection se détend à
l’usage, ce qui perturbe son bon fonctionnement. Un ré-
glage régulier du câble est indispensable pour éviter ce
problème. Il convient toutefois de confier ce réglage à un
concessionnaire Yamaha.
FBU13770
Contrôle des plaquettes de frein avant
S’assurer que les plaquettes de frein ne sont ni endomma-
gées ni usées. Si l’épaisseur est inférieure à 1,0 mm, faire
remplacer la ou les paires de plaquettes par un conces-
sionnaire Yamaha.N.B.:_ Il est nécessaire de déposer les roues pour effectuer le con-
trôle des plaquettes de frein. (Voir les explications relati-
ves à leur dépose et à leur mise en place aux pages 8-82 à
8-84 .)
SBU03050
Ajuste del cable del sistema de seguridad de la
palanca selectora
El cable del sistema de seguridad de la palanca se-
lectora se estira con el uso, dando lugar a un funcio-
namiento incorrecto del mismo. Para evitarlo, se
debe ajustar el cable periódicamente. Este ajuste,
sin embargo, debe realizarlo un concesionario
Yamaha.
SBU13770
Inspección de las pastillas del freno delantero
Compruebe el grado de desgaste y si hay daños en
las pastillas del freno. Si el espesor de una pastilla es
de menor de 1,0 mm, encargue a un concesionario
Yamaha que sustituya las pastillas como un conjun-
to.NOTA:_ Para inspeccionar las pastillas del freno, es necesa-
rio desmontar las ruedas. (Para más detalles sobre
el procedimiento de desmontaje y de instalación, vea
las página 8-82–8-84.)
U1P060.book Page 56 Monday, August 2, 2004 12:19 PM

8-57 1. Wear indicator 2. Wear limit line
1. Indicateur d’usure 2. Ligne de limite d’usure
1. Indicador de desgaste 2. Límite de la línea de desgaste
EBU00313
Rear brake shoe inspection
A wear indicator is provided on the rear brake.
This indicator allows checking of brake shoe wear
without disassembling the brake. Apply the rear
brake and check the position of the indicator. If the
indicator reaches the wear limit line, ask a
Yamaha dealer to replace shoes as a set.
U1P060.book Page 57 Monday, August 2, 2004 12:19 PM

8-63 1. Front brake lever
a. Front brake lever free play
1. Levier de frein avant
a. Jeu du levier de frein avant
1. Palanca del freno delantero
a. Juego de la palanca del freno delantero
EBU11880
Front brake lever free play
The front brake lever should have a free play of
zero mm at the lever end. If not, have a Yamaha
dealer check the brake system.
WARNING
_ Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability
which could lead to an accident.
After servicing:

Make sure the brakes operate smoothly
and that the free play is correct.


Make sure the brakes do not drag.


Make sure the brakes are not spongy. All
air must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
U1P060.book Page 63 Monday, August 2, 2004 12:19 PM

8-71 1. Locknut 2. Adjusting bolt
a. Rear brake lever free play
1. Contre-écrou 2. Boulon de réglage
a. Jeu du levier de frein arrière
1. Contratuerca 2. Perno de ajuste
a. Juego de la palanca de freno trasero
3. Turn the adjusting bolt until free play at the
brake lever pivot is 5.0–7.0 mm.
4. Tighten the locknut.
5. Install the footboard.
WARNING
_ Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:

Make sure the brakes operate smoothly
and that the free play is correct.


Make sure the brakes do not drag.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
U1P060.book Page 71 Monday, August 2, 2004 12:19 PM