2005 YAMAHA YFZ450 engine

8-1
EBU05160
1-PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
WARNING
_ Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service. _
U5TG61.book Page 1 Friday, April 2, 2004 11:28 AM

8-7
EBU02621
PERIODIC MAINTENANCE/LUBRICATION
NOTE:_

For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.


For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance in-
tervals. However, keep in mind that if the ATV isn’t used for a long period of time, the month mainte-
nance intervals should be followed.
_
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
Valves*Check valve clearance.
Adjust if necessary.
Cooling systemCheck for coolant leakage.
Repair if necessary.
Replace coolant every 24 months.Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check starter (choke) operation.
Adjust engine idling speed.Crankcase breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Tighten if necessary.
Replace gasket if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace (Warm engine before draining).U5TG61.book Page 7 Friday, April 2, 2004 11:28 AM

8-8 * Since these items require special tools, data and technical skills, have a Yamaha dealer perform the service.
Engine oil filter element
Replace.Drive chain
Check and adjust slack/alignment/clean/lube.Front brake*Check free play/operation/fluid leakage/
See NOTE Page 8-9.
Correct if necessary.Rear brake*Check operation/fluid leakage/See NOTE Page 8-9.
Correct if necessary.Clutch*Check operation.
Adjust if necessary.Wheels*Check balance/damage/runout.
Replace if necessary.Wheel bearings*Check bearing assemblies for looseness/damage.
Replace if damaged.Steering system*Check operation.
Repair if damaged.
Check toe-in.
Adjust if necessary.Front and rear
suspension*Check operation.
Correct if necessary.Upper and lower arm
pivot and steering shaft*Lubricate every 6 months with lithium-soap-based grease.Rear arm pivot*
Lubricate every 6 months with lithium-soap-based grease.Fittings and fasteners*Check all chassis fittings and fasteners.
Correct if necessary.Lights and switches*Check operation.
Adjust headlight beams.
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
U5TG61.book Page 8 Friday, April 2, 2004 11:28 AM

8-23
EBU13932
Engine oil and oil filter element
The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter element replaced at the intervals spec-
ified in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up until the engine
oil has reached a normal temperature of
40°C, let it continue to idle for ten seconds or
more, and then turn the engine off.NOTE:_ To achieve the proper engine oil temperature for
an accurate oil level reading, the engine must
have first completely cooled down, and then
warmed up again for several minutes to normal
operating temperature. _
U5TG61.book Page 23 Friday, April 2, 2004 11:28 AM

8-25 1. Engine oil tank 2. Engine oil tank filler cap
3. Dipstick 4. Maximum level mark
5. Minimum level mark 6. Engine oil filler cap
1. Réservoir d’huile de moteur
2. Bouchon de remplissage de l’huile de moteur
3. Jauge
4. Repère de niveau maximum
5. Repère de niveau minimum
6. Bouchon de remplissage d’huile de moteur
1. Depósito de aceite de motor
2. Tapa de relleno del depósito de aceite de motor
3. Varilla de medición
4. Marca de nivel máximo
5. Marca de nivel mínimo
6. Tapa del filtro de aceite de motor
3. Remove the engine oil tank filler cap, wipe
the dipstick clean with a clean rag, insert it
back into the filler hole (without screwing it
in), and then remove it again to check the oil
level.NOTE:_ The engine oil should be between the minimum
and maximum level marks. _4. If the engine oil is below the minimum level
mark, add sufficient oil of the recommended
type through the engine oil tank filler hole to
raise it to the correct level.NOTE:_ When adding oil, be careful not to overfill the en-
gine oil tank; the oil level rises faster starting from
the half-level-portion on the dipstick. _5. Insert the dipstick into the engine oil tank filler
hole, and then tighten the engine oil tank filler
cap.
U5TG61.book Page 25 Friday, April 2, 2004 11:28 AM

8-27 1. Engine guard 2. Bolt (× 6)
1. Protège-carter 2. Boulon (× 6)
1. Protector del motor 2. Perno (× 6)
CAUTION:_ Make sure that the engine oil tank filler cap is
securely tightened, otherwise oil may seep out
when the engine is running. _To change the engine oil (with or without oil fil-
ter element replacement)
1. Remove the engine guard by removing the
bolts.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the engine to collect
the used oil.
U5TG61.book Page 27 Friday, April 2, 2004 11:28 AM

8-29 1. Crankcase engine oil drain bolt
1. Boulon de vidange d’huile du carter
1. Perno de drenaje de aceite de motor del cárter
1. Engine oil tank drain bolt
1. Boulon de vidange du réservoir d’huile
1. Perno de drenaje del depósito aceite de motor
4. Remove the engine oil filler cap and the
crankcase engine oil drain bolt.
5. Remove the engine oil tank filler cap and the
engine oil tank drain bolt.
6. Check the washers for damage, and replace
if necessary.
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8-33
11. Install the crankcase engine oil drain bolt and
the engine oil tank drain bolt, and then tighten
them to the specified torques.
12. Pour the specified amount of recommended
engine oil through the engine oil tank filler
hole, insert the dipstick, and then tighten the
engine oil tank filler cap.
13. Pour the specified amount of recommended
engine oil through the engine oil filler hole,
and then install and tighten the engine oil filler
cap. Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf)
Tightening torques:
Crankcase engine oil drain bolt:
20 Nm (2.0 m·kgf)
Engine oil tank drain bolt:
19 Nm (1.9 m·kgf)
U5TG61.book Page 33 Friday, April 2, 2004 11:28 AM