2006 YAMAHA BRUIN 250 compression

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.
EE.book Page 57 Friday, May 27, 2005 5:00 PM

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.
EE.book Page 19 Friday, May 27, 2005 5:00 PM

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

8-25
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

8-105
EBU00413
Troubleshooting
Although Yamaha machines receive a rigid in-
spection before shipment from the factory, trouble
may occur during operation.
Any problem in the fuel, compression, or ignition
systems can cause poor starting and loss of pow-
er. The troubleshooting chart describes a quick,
easy procedure for making checks. If your ma-
chine requires any repair, take it to a Yamaha
dealer.
The skilled technicians at a Yamaha dealership
have the tools, experience, and know-how to prop-
erly service your machine. Use only genuine
Yamaha parts on your machine. Imitation parts
may look like Yamaha parts, but they are often in-
ferior. Consequently, they have a shorter service
life and can lead to expensive repair bills.
WARNING
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe in-
jury or property damage. Make sure there are
no open flames or sparks in the area, including
pilot lights from water heaters or furnaces.
EE.book Page 105 Friday, May 27, 2005 5:00 PM

8-107
EBU00440Troubleshooting chart
1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.Turn the fuel cock
lever to “OFF”.
Turn the fuel cock
lever to “ON”. Remove the
fuel hose. No fuel.
Clean fuel
cock. Some fuel.Turn the fuel
cock to “RES”.Restart engine.
No fuel.Supply fuel.
2. Compression
Use electric starter to
see if there is
compression.There is compression.
Compression normal.
No compression.Ask a Yamaha dealer to
inspect.
3. Ignition
Remove spark plug and
check electrodes.
WetWipe clean with dry cloth.
DryAttach spark plug cap and
ground to chassis.Use the
electric starter.Spark good.Ignition system
normal.
Spark weak.
Adjust plug gap
or replace plug. No spark.
Ask a Yamaha dealer to
inspect. 4. Battery
Use electric starter.Engine turns over
quickly.Battery good.
Engine turns over
slowly.Check fluid, recharge,
check connections.Check fuel
flow.
Fuel cock
clogged.
EE.book Page 107 Friday, May 27, 2005 5:00 PM

8-108
FBU00440Tableau de dépannage
Pas de carburantRobinet de carburant
obstrué
Nettoyer le robinet
de carburant.
1. Carburant
Vérifier s’il y a du
carburant dans le
réservoir.Il y a du
carburant.Placer la manette du robinet
de carburant sur "OFF" Déposer le flexible de
carburant.
Placer la manette du robinet
de carburant sur "ON"
Un peu
de carburantTourner le robinet
de carburant sur “RES”.Remettre le moteur en
marche.
Pas
de carburantSe ravitailler en
carburant.
2. Compression
Utiliser le démarreur
électrique pour voir s’il
y a compression.Compression Compression normale
Pas de compressionDemander au concessionnaire
Yamaha de vérifier.
3. Allumage
Déposer la bougie et
contrôler les électrodes.Électrodes
humidesNettoyer avec un chiffon sec.
Électrodes
sèchesRemettre le capuchon de la
bougie en place et le mettre à
la masse au châssis.Utiliser le
démarreur
électrique.Bonne
étincelleAllumage normal
Faible
étincelle
Régler l’écartement des
électrodes ou remplacer la
bougie. Pas
d’étincelle
Demander à un concessionnaire
Yamaha de vérifier. 4. Batterie
Utiliser le démarreur
électrique.Le moteur tourne
rapidement.La batterie est en bon état.
Le moteur tourne
lentement.Contrôler le liquide, recharger,
contrôler les branchements.
Vérifier si le
carburant coule.
EE.book Page 108 Friday, May 27, 2005 5:00 PM

10-1
EBU00428
SPECIFICATIONS
Model YFM25BV
Dimension:
Overall length 1,916 mm
Overall width 1,038 mm
Overall height 1,118 mm
Seat height 772 mm
Wheelbase 1,170 mm
Minimum ground clearance 150 mm
Minimum turning radius 2,900 mm
Basic weight:
With oil and full fuel tank 216.0 kg
Noise and vibration level:
Noise level (77/311/EEC) (For Europe) 77.5 dB (A)
Vibration on seat (EN1032, ISO5008)
(For Europe) Will not exceed 0.5 (m/s
2)
Vibration on handlebar (EN1032, ISO5008)
(For Europe) Will not exceed 2.5 (m/s2)
Engine:
Type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 229.6 cm
3
Bore
× stroke 71.0
× 58.0 mm
Compression ratio 8.70:1
EE.book Page 1 Friday, May 27, 2005 5:00 PM