2005 YAMAHA BIG BEAR PRO 400 engine

8-19 1. Engine oil drain bolt 2. O-ring
3. Compression spring 4. Oil strainer
1. Boulon de vidange de l’huile 2. Joint torique
3. Ressort de compression 4. Crépine à huile
1. Perno de drenaje del aceite de motor 2. Junta tórica
3. Muelle de compresión 4. Colador de aceite
1. Clamp
1. Bride
1. Mordaza
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.
U1C160.book Page 19 Wednesday, May 12, 2004 4:55 PM

8-21 1. Engine oil filter element cover bolt (× 3)
2. Oil filter element cover
3. Bolt
1. Boulon de couvercle de l’élément de filtre à huile moteur (× 3)
2. Couvercle de l’élément de filtre à huile
3. Boulon
1. Perno de la tapa del elemento del filtro de aceite de motor (× 3)
2. Tapa del elemento del filtro de aceite
3. Perno
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 shift pedal by removing the bolt.
6. Remove the clamp by removing the screw.
7. Remove the oil filter element cover by remov-
ing the bolts, and then remove the oil filter el-
ement.
8. Clean the oil strainer and oil filter element
with solvent.
9. Check the O-ring for damage and replace it if
necessary.
10. Install the oil filter element and O-ring.NOTE:_ Make sure the O-ring is seated properly. _
U1C160.book Page 21 Wednesday, May 12, 2004 4:55 PM

8-23 1. Engine oil filter element 2. O-ring (× 2)
1.Élément du filtre à huile moteur 2. Joint torique (× 2)
1. Element del filtro de aceite de motor 2. Junta tórica (× 2)
11. Install the oil filter element cover by installing
the bolts, and then tighten them to the speci-
fied torque.
12. Install the oil strainer, compression spring,
O-ring and engine oil drain bolt. Tighten the
engine oil drain bolt to the specified 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:
32 Nm (3.2 m·kgf)
U1C160.book Page 23 Wednesday, May 12, 2004 4:55 PM

8-25
13. Add the specified amount of the recommend-
ed engine oil, and then install and tighten the
engine 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 oil:
See page 10-2.
Oil quantity:
Without oil filter element replacement:
2.40 L
With oil filter element replacement:
2.50 L
U1C160.book Page 25 Wednesday, May 12, 2004 4:55 PM

8-27
14. Install the clamp by installing the screw.
15. Install the shift pedal by installing the bolt.
16. 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.
17. Turn the engine off, and then check the oil
level and correct it if necessary.
U1C160.book Page 27 Wednesday, May 12, 2004 4:55 PM

8-29 1. Bolt (× 3)
1. Boulon (× 3)
1. Perno (× 3)
1. Oil filler bolt
1. Boulon de l’orifice de remplissage d’huile
1. Perno del orificio de llenado de aceite
EBU00462
Transfer gear oil replacementNOTE:When replacing the transfer gear oil, replace the
engine oil also.1. Remove the transfer gear case guard.
2. Place the machine on a level place.
3. Place a container under the transfer gear
case.
4. Remove the oil filler bolt and drain bolt to
drain the oil.
5. Install the drain bolt and tighten to specifica-
tion.
Tightening torque:
Drain bolt (transfer gear case):
20 Nm (2.0 m·kgf)
U1C160.book Page 29 Wednesday, May 12, 2004 4:55 PM

8-31 1. Drain bolt
1. Boulon de vidange
1. Perno de drenaje
6. Fill the transfer gear case with oil.CAUTION:
Be sure no foreign material enters the transfer
gear case.7. Install the filler bolt and tighten to specifica-
tion.
8. Check for oil leakage. If oil leakage is found,
check for the cause.
9. Reinstall the transfer gear case guard.Recommended oil: See page 10-2
Quantity:
Transfer gear oil and engine oil with
filter replacement:
2.8 L
Tightening torque:
Filler bolt (transfer gear case):
23 Nm (2.3 m·kgf)
U1C160.book Page 31 Wednesday, May 12, 2004 4:55 PM

8-43 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
1. Spark plug wrench
1. Clé à bougie
1. Llave de bujías
EBU11820
Spark plug 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.
For example, a very white center electrode porce-
lain color could indicate an intake air leak or carbu-
retion problem for that cylinder. Do not attempt to
diagnose such problems yourself.
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, you should re-
place the spark plug with one of the proper type.
Standard spark plug:
DR8EA (NGK)
U1C160.book Page 43 Wednesday, May 12, 2004 4:55 PM