2005 YAMAHA YFZ450 engine

8-148
Engine overheatingNOTE:_ If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible. _
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. _ Wait until the
engine has cooled.
Check the coolant level in the
coolant reservoir and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and/or repair the cooling system.
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9-1
EBU04180
1-CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine will
not only enhance its appearance but will improve
its general performance and extend the useful life
of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to pre-
vent water entry. A plastic bag and strong
rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy, ap-
ply degreaser with a paint brush. Do not ap-
ply degreaser to the chain, sprockets or
wheel axles.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the
job.
U5TG61.book Page 1 Friday, April 2, 2004 11:28 AM

9-5
8. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or protec-
tive finish. When finished, start the engine
and let it idle for several minutes.
WARNING
_ Wet brakes may have reduced stopping ability,
increasing the chance of an accident. Test the
brakes after washing. Apply the brakes several
times at slow speeds to let friction dry out the
linings. _
U5TG61.book Page 5 Friday, April 2, 2004 11:28 AM

9-7
EBU05260
B. STORAGE
Long term storage (60 days or more) of your ma-
chine will require some preventive procedures to
guard against deterioration. After thoroughly
cleaning the machine, prepare for storage as fol-
lows:
1. Fill the fuel tank with fresh fuel and add fuel
stabilizer (if available).NOTE:_ Use of fuel stabilizer eliminates the need to drain
the fuel system. Consult a Yamaha dealer if the
fuel system is to be drained instead. _2. Remove the spark plug, pour about one ta-
blespoon of SAE 10W30 or 20W40 motor oil
in the spark plug hole and reinstall the spark
plug. Ground the spark plug wire and turn the
engine over several times to coat the cylinder
wall with oil.
3. Clean the drive chain thoroughly and lubri-
cate it. (See page 8-107.)
4. Lubricate all control cables.
U5TG61.book Page 7 Friday, April 2, 2004 11:28 AM

10-1
EBU04280
1-SPECIFICATIONS
MODEL YFZ450
Dimension:
Overall length
Overall width
Overall height
Seat height
Wheel base
Ground clearance
Minimum turning radius1,840 mm
1,170 mm
1,090 mm
800 mm
1,280 mm
255 mm
3,500 mm
Basic weight:
With oil and full fuel tank 169.0 kg
Engine:
Type
Cylinder arrangement
Displacement
Bore
× stroke
Compression ratio
Starting system
Lubrication systemLiquid-cooled, 4-stroke, DOHC
Forward inclined single cylinder
439.0 cm
3
95.0
× 62.0 mm
11.90 : 1
Electric starter
Dry sump
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10-2
10
Engine oil:
Type
Recommended engine oil classification API Service SE, SF, SG type or higher
Quantity:
Without oil filter element replacement
With oil filter element replacement1.75 L
1.85 L MODEL YFZ450
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
CAUTION:In order to prevent clutch slippage (since the en-
gine 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.
U5TG61.book Page 2 Friday, April 2, 2004 11:28 AM