2006 YAMAHA YZ450F check engine

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and oil
line for leakage.P.3-13 ~ 17
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9 ~ 10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-24 ~ 30
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-31 ~ 33
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-41 ~ 42
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-42 ~ 44
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-33 ~ 40
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Muffler Check that the muffler is tightly mounted and has no cracks.—
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-31
Lubrication Check for smooth operation. Lubricate if necessary. P.3-45
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 21

3 - 5
INSP
ADJ
EC350000
ENGINE
EC351011
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap
1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
1. Place the machine on a level place, and
hold it in an upright position.
2. Remove:
Radiator cap
3. Check:
Coolant level a
Coolant level low → Add coolant.
1Radiator
ENGINE/COOLANT LEVEL INSPECTION

3 - 7
INSP
ADJ
RADIATOR CAP INSPECTION
CAUTION:
Do not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
Do not use water containing impurities or
oil.
7. Install:
Radiator cap
Start the engine and warm it up for a sev-
eral minutes.
8. Check:
Coolant level
Coolant level low → Add coolant. Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
When coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
When coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
When coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
EC355000
RADIATOR CAP INSPECTION
1. Inspect:
Seal (radiator cap) 1
Valve and valve seat 2
Crack/damage → Replace.
Exist fur deposits 3 → Clean or replace.

3 - 10
INSP
ADJTHROTTLE CABLE ADJUSTMENT/
THROTTLE LUBRICATION
3. Install:
Cap 1
Boot 2
NOTE:
Place the tip a of the cap in the boot.
EC35A001
THROTTLE CABLE ADJUSTMENT
1. Check:
Throttle grip free play a
Out of specification → Adjust.
2. Adjust:
Throttle grip free play
Throttle grip free play
a:
3 ~ 5 mm (0.12 ~ 0.20 in)
Throttle grip free play adjustment steps:
Slide the adjuster cover.
Loosen the locknut 1.
Turn the adjuster 2 until the specified free
play is obtained.
Tighten the locknut.
T R..
Locknut:
4 Nm (0.4 m  kg, 2.9 ft  lb)
NOTE:
Before adjusting the throttle cable free play,
the engine idle speed should be adjusted.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
1 2
THROTTLE LUBRICATION
1. Remove:
Cover (throttle cable cap) 1
Cover (grip cap) 2
Throttle cable cap 3

3 - 11
INSP
ADJHOT STARTER LEVER ADJUSTMENT/
AIR FILTER CLEANING
2. Apply:
Lithium soap base grease
On the throttle cable end a.
3. Install:
Throttle cable cap
Screw (throttle cable cap)
Cover (grip cap)
Cover (throttle cable cap)
HOT STARTER LEVER ADJUSTMENT
1. Check:
Hot starter lever free play a
Out of specification → Adjust.
2. Adjust:
Hot starter lever free play
NOTE:
After adjustment, check proper operation of
hot starter.
EC35G040
AIR FILTER CLEANING
NOTE:
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage.
CAUTION:
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage.
1. Remove:
Seat
Fitting bolt 1
Washer 2
Air filter element 3
Filter guide 4
Hot starter lever free play
a:
3 ~ 6 mm (0.12 ~ 0.24 in)
Hot starter lever free play adjustment
steps:
Loosen the locknut 1.
Turn the adjuster 2 until free play a is
within the specified limits.
Tighten the locknut.
T R..
Locknut:
4 Nm (0.4 m  kg, 2.9 ft  lb)
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)

3 - 13
INSP
ADJ
7. Install:
Air filter element 1
Washer
Fitting bolt
NOTE:
Align the projection a on filter guide with the
hole b in air filter case.
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
ENGINE OIL LEVEL INSPECTION
1. Stand the machine on a level surface.
NOTE:
When checking the oil level make sure that
the machine is upright.
Place the machine on a suitable stand.
WARNING
Never remove the oil tank cap just after
high speed operation. The heated oil could
spurt out. causing danger. Wait until the oil
cools down to approximately 70 °C (158 °F).
2. Idle the engine more than 3 minutes while
keeping the machine upright. Then stop the
engine and inspect the oil level.
3. Remove:
Oil tank cap 1
ENGINE OIL LEVEL INSPECTION

3 - 14
INSP
ADJ
ENGINE OIL LEVEL INSPECTION
4. Inspect:
Oil level
Remove the oil tank cap and check that
engine oil is above the level mark a.
Below the level mark a → Add oil above
the level mark a.
Above the level mark b → Remove the
check bolt 1 and drain the oil until it
stops coming out.
NOTE:
When inspecting the oil level, do not screw the
oil level gauge into the oil tank.
Insert the gauge lightly.
(For USA and CDN)
CAUTION:
Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
Do not allow foreign material to enter the
crankcase.
(Except for USA and CDN)
Recommended oil:
At 5 °C (40 °F) or higher
È
Yamalube 4 (20W-40) or SAE
20W-40 type SG motor oil
(Non-Friction modified)
At 15 °C (60 °F) or lower
É
Yamalube 4 (10W-30) or SAE
10W-30 type SG motor oil
(Non-Friction modified)
and/or
Yamalube 4-R (15W-50)
(Non-Friction modified)
Recommended oil:
Refer to the following chart for
selection of oils which are
suited to the atmospheric
temperatures.
Recommended engine oil classi-
fication:
API STANDARD:
API “SG” or higher grade
(Designed primarily for
motorcycles)
-20
-4-10
140
3010
5020
6830
8640 50
104
122 ˚CTemp.
˚F
10W-30
10W-40
20W-40
20W-50
15W-40

3 - 16
INSP
ADJ
ENGINE OIL REPLACEMENT
4. If the oil filter is to be replaced during this
oil change, remove the following parts and
reinstall them.
Replacement steps:
Remove the oil filter cover 1 and oil filter
element 2.
Check the O-rings 3, if cracked or dam-
aged, replace them with a new one.
Install the oil filter element and oil filter
cover.
T R..
Oil filter cover:
10 Nm (1.0 m  kg, 7.2 ft  lb)
5. Install:
Gaskets
Oil filter drain bolt
Drain bolt (crankcase right)
Drain bolt (crankcase left)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
6. Fill:
Crankcase
Oil quantity:
Periodic oil change:
0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement:
1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount:
1.2 L (1.06 Imp qt, 1.27 US qt)