2007 YAMAHA YZ450F clutch

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 - 9
INSP
ADJ
CLUTCH ADJUSTMENT
NOTE:
Do not apply pressure more than specified
pressure.
Radiator should be filled fully.
4. Inspect:
Pressure
Impossible to maintain the specified pres-
sure for 10 seconds → Repair.
Radiator
Radiator hose joint
Coolant leakage → Repair or replace.
Radiator hose
Swelling → Replace.
EC359020
CLUTCH ADJUSTMENT
1. Check:
Clutch lever free play a
Out of specification → Adjust.
Clutch lever free play
a:
8 ~ 13 mm (0.31 ~ 0.51 in)
2. Adjust:
Clutch lever free play
NOTE:
Before adjustment, expose the adjuster by
moving the boot 3 and cap 4 away.
Make minute adjustment on the lever side
using the adjuster 5.
After adjustment, check proper operation of
clutch lever. Clutch 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)

3 - 14
INSP
ADJ
ENGINE OIL LEVEL INSPECTION
4. Inspect:
Oil level
Check that the engine oil is above the
level mark a and that the oil does not
come out when the check bolt 1 is
removed.
Below the level mark a → Add oil
through the filler cap hole until it is above
the level mark a.
Oil comes out at the check bolt → 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)
CAUTION:
Do not add any chemical additives or use
oils with a grade of CD
a or higher.
Do not use oils labeled “ENERGY CON-
SERVING II”
b or higher. Engine oil also
lubricates the clutch and additives could
cause clutch slippage.
Do not allow foreign materials to enter the
crankcase.
Recommended oil:
Yamalube 4, SAE10W30 or
SAE 20W40
Yamalube 4-R, SAE10W50
API service SG type or higher
JASO standard MA
Recommended oil:
SAE10W30, SAE10W40,
SAE15W40, SAE20W40 or
SAE20W50
API service SG type or higher
JASO standard MA
-20 -10 0 10 20 30 40 50
˚C 0 10 30 50 70 90 110 130
˚F
YAMALUBE 4(10W-30) or SAE 10W-30
YAMALUBE 4(20W-40) or SAE 20W-40
YAMALUBE 4-R(10W-50) or SAE 10W-50
-20 -10 0 10 20 30 40 50
˚C
SAE 10W-30
SAE 10W-40
SAE 15W-40
SAE 20W-40
SAE 20W-50
a
b

3 - 45
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable end
0Hot starter cable endÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC

4 - 2
ENG
REMOVAL POINTS
Side cover
1. Remove:
Bolt (side cover)
Side cover (left) 1
Side cover (right) 2
NOTE:
Draw the side cover downward to remove it
because its claws a are inserted in the air fil-
ter case.
Number plate
1. Remove:
Bolt (number plate)
Number plate 1
NOTE:
The projection a is inserted into the band of
the number plate. Pull the band off the pro-
jection before removal.
Remove the hot starter cable 2 and clutch
cable 3 from the cable guide b on the num-
ber plate.
The projection c on the under bracket is
inserted into the number plate. Remove the
number plate by pulling it off the projection.
ASSEMBLY AND INSTALLATION
Air scoop
1. Install:
Air scoop 1
Bolt (air scoop)
NOTE:
Put the portion a of the flap of the air filter
case on the inside of the air scoop.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
SEAT, FUEL TANK AND SIDE COVERS

4 - 49
ENGCLUTCH
CLUTCH
CLUTCH
Extent of removal:
1 Push rod and push lever removal
2 Push rod 1 disassembly
3 Friction plate and clutch plate removal
4 Clutch housing removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Gasket 1
3 Dowel pin 2
4 Clutch spring 6
5 Pressure plate 1
6 Push rod 1 1
7 Circlip 1
8 Plain washer 1
9 Bearing 1
10 Ball 1
11 Push rod 2 1
41
2
3
1

4 - 50
ENGCLUTCH
Extent of removal Order Part name Q’ty Remarks
12 Clutch plate 7
13 Friction plate 8
14 Nut 1
Use special tool.
Refer to “REMOVAL POINTS”. 15 Lock washer 1
16 Clutch boss 1
17 Thrust washer 1
18 Clutch housing 1
19 Push lever 1
4
1
3

4 - 51
ENGCLUTCH
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
Nut 1
Lock washer 2
Clutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4 to hold the clutch boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
È
É
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
Clutch housing 1
Cracks/wear/damage → Replace.
Clutch boss 2
Scoring/wear/damage → Replace.
EC484201
Primary driven gear
1. Check:
Circumferential play
Free play exists → Replace.
Gear teeth
a
Wear/damage → Replace.
EC484400
Clutch spring
1. Measure:
Clutch spring free length
a
Out of specification → Replace springs
as a set.
Clutch spring free length:
Standard
50.0 mm (1.97 in) 49.0 mm (1.93 in)