2005 YAMAHA YFZ450 engine

8-35
Recommended engine oil:
See page 10-2.
Oil quantity:
Without oil filter element replacement:
Quantity in oil tank:
1.55 L
Quantity in crankcase:
0.20 L
Total amount:
1.75 L
With oil filter element replacement:
Quantity in oil tank:
1.55 L
Quantity in crankcase:
0.30 L
Total amount:
1.85 L
U5TG61.book Page 35 Friday, April 2, 2004 11:28 AM

8-37
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.
_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 engine guard by installing the bolts,
and then tighten them to the specified torque.
U5TG61.book Page 37 Friday, April 2, 2004 11:28 AM

8-39
CAUTION:_ Be sure to apply LOCTITE
® to the engine guard
bolts before installing them.
_
Tightening torque:
Engine guard bolt:
7 Nm (0.7 m·kgf)
U5TG61.book Page 39 Friday, April 2, 2004 11:28 AM

8-41 1. Maximum level mark 2. Minimum level mark
3. Coolant reservoir 4. Coolant reservoir cap
1. Repère de niveau maximum 2. Repère de niveau minimum
3. Vase d’expansion 4. Bouchon du vase d’expansion
1. Marca de nivel máximo 2. Marca de nivel mínimo
3. Depósito de refrigerante
4. Tapa del depósito de líquido refrigerante
EBU10151
Cooling system
1. Check the coolant level in the coolant reser-
voir when the engine is cold as the coolant
level will vary with engine temperature.NOTE:_ The coolant should be between the minimum and
maximum level marks. _2. If the coolant is at or below the minimum level
mark, remove the coolant reservoir cap, and
then add coolant or distilled water to raise it to
the specified level.CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you can’t get
distilled water. _
Coolant reservoir capacity
(up to the maximum level mark):
0.29 L
U5TG61.book Page 41 Friday, April 2, 2004 11:28 AM

8-45 1. Coolant drain bolt 2. Trough
1. Boulon de vidange du liquide de refroidissement
2. Feuille de papier pliée comme illustré
1. Perno de drenaje de refrigerante
2. Elemento de paso
1. Radiator cap
1. Bouchon de radiateur
1. Tapa del radiador
EBU14130
Changing the coolant
WARNING
_ Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always put a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap. _1. Place the ATV on a level surface.
2. Remove panel A. (See page 8-17 for panel
removal and installation procedures.)
3. Place a container under the engine, and then
remove the coolant drain bolt. (Use a trough
or a similar object as shown.)
4. Remove the radiator cap.
U5TG61.book Page 45 Friday, April 2, 2004 11:28 AM

8-51
CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you cannot get
distilled water. _12. Install the radiator cap and the coolant reser-
voir cap.
13. Start the engine and let it idle for several min-
utes. Stop the engine, and then check the
coolant level in the radiator. If it is low, add
more coolant until it reaches the top of the ra-
diator.
14. Check the coolant level in the reservoir. If it is
low, add coolant to the maximum level mark.
15. Start the engine and then check for coolant
leakage.NOTE:_ If any leakage is found, have a Yamaha dealer
check the cooling system. _16. Install the panel.
U5TG61.book Page 51 Friday, April 2, 2004 11:28 AM

8-53 1. Panel 2. Bolt (× 2)
3. Quick fastener screw (× 2) 4. Fuel tank cap
1. Cache 2. Boulon (× 2)
3. Vis à serrage rapide (× 2)
4. Bouchon du réservoir de carburant
1. Panel 2. Perno (× 2)
3. Perno del fijador rápido (× 2)
4. Tapón del depósito de combustible
EBU14142
Spark plug inspection
Removal
1. Remove the seat. (See page 4-27 for seat re-
moval and installation procedures.)
2. Remove the bolts and the quick fastener
screws.
3. Remove the fuel tank cap by turning it coun-
terclockwise.
WARNING
_

Always turn off the engine when removing
the fuel tank cap.


Do not remove the fuel tank cap immedi-
ately after the engine has been running
and is still very hot.


Do not spill gasoline on the engine, ex-
haust pipe or muffler.


Never remove the fuel tank cap while
smoking, or in the vicinity of sparks, open
flames, or other sources of ignition such
as the pilot lights of water heaters and
clothes dryers.
_
U5TG61.book Page 53 Friday, April 2, 2004 11:28 AM

8-57 1. Spark plug wrench
1. Clé à bougie
1. Llave de bujía
8. 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.
U5TG61.book Page 57 Friday, April 2, 2004 11:28 AM