fuel YAMAHA WR 450F 2006 Owner's Manual

3 - 19
INSP
ADJ
VALVE CLEARANCE ADJUSTMENT
VALVE CLEARANCE ADJUSTMENT
NOTE:
The valve clearance should be adjusted
when the engine is cool to the touch.
The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
Seat
Fuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
2. Remove:
Carburetor
Refer to “CARBURETOR” section in the
CHAPTER 4.
Spark plug
Engine stay (upper)
Cylinder head cover
Refer to “CAMSHAFTS” section in the
CHAPTER 4.
3. Remove:
Timing plug 1
Straight plug 2
O-ring
1
2
4. Check:
Valve clearance
Out of specification → Adjust.
Valve clearance (cold):
Intake valve:
0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)
Exhaust valve:
0.20 ~ 0.25 mm
(0.0079 ~ 0.0098 in)
Checking steps:
Turn the crankshaft counterclockwise with
a wrench.
Align the T.D.C. mark a on the rotor with
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.
b
a

3 - 45
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
Tighten the ring nut 3 using ring nut
wrench 4.
NOTE:
Apply the lithium soap base grease on the
thread of the steering shaft.
Set the torque wrench to the ring nut
wrench so that they form a right angle.
Ring nut wrench:
YU-33975/90890-01403
T R..
Ring nut (initial tightening):
38 Nm (3.8 m  kg, 27 ft  lb)
Loosen the ring nut one turn.
Retighten the ring nut using the ring nut
wrench.
WARNING
Avoid over-tightening.
T R..
Ring nut (final tightening):
7 Nm (0.7 m  kg, 5.1 ft  lb)
Check the steering shaft by turning it lock
to lock. If there is any binding, remove the
steering shaft assembly and inspect the
steering bearings.
Install the plain washer 5, handle crown
6, plain washer 7, steering shaft nut 8,
steering shaft cap 9, handlebar 0, han-
dlebar holder (upper) A and headlight B.
NOTE:
The handlebar holder (upper) should be
installed with the punched mark a for-
ward.
Install the handlebar so that the marks b
are in place on both sides.
Insert the end of the fuel breather hose C
into the hole in the steering shaft cap.
CAUTION:
First tighten the bolts on the front side of
the handlebar holder (upper), and then
tighten the bolts on the rear side.

3 - 57
INSP
ADJ
REPLACING THE HEADLIGHT BULBS
3. Replace:
Blown fuse
WARNING
Never use a fuse with an amperage rating
other than that specified. Improvising or
using a fuse with the wrong amperage rat-
ing may cause extensive damage to the
electrical system, cause the starting and
ignition systems to malfunction and could
possibly cause a fire.
4. Install:
Fuse cover
Seat Replacement steps:
Set the main switch to “OFF”.
Install a new fuse of the correct amperage.
Set on the switches to verify if the electri-
cal circuit is operational.
If the fuse immediately blows again, check
the electrical circuit.
ItemsAmperage
ratingQ’ty
Main fuse 10 A 1
REPLACING THE HEADLIGHT BULBS
1. Remove:
Headlight
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
2. Remove:
Headlight bulb holder cover 1
3. Detach:
Headlight bulb holder 1
4. Remove:
Headlight bulb 2
WARNING
Since the headlight bulb gets extremely
hot, keep flammable products and your
hands away from the bulb unit it has cooled
down.

3 - 58
INSP
ADJ
ADJUSTING THE HEADLIGHT BEAMS
5. Install:
Headlight bulb
Secure the new headlight bulb with the
headlight bulb holder.
CAUTION:
Avoid touching the glass part of the head-
light bulb to keep it free form oil, otherwise
the transparency of the glass, the life of the
bulb and the luminous flux will be
adversely affected. If the headlight bulb
gets soiled, thoroughly clean it with a cloth
moistened with alcohol or lacquer thinner.
6. Attach:
Headlight bulb holder
7. Install:
Headlight bulb holder cover
8. Install:
Headlight
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
New
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
ADJUSTING THE HEADLIGHT BEAMS
1. Adjust:
Headlight beam (vertically)
Adjusting steps:
Turn the adjusting screw 1 in direction a
or b.
Direction a Headlight beam is raised.
Direction bHeadlight beam is lowered.

4 - 1
ENG
EC400000
ENGINE
EC4R0000
SEAT, FUEL TANK AND SIDE COVERS
Extent of removal:
1 Seat removal
2 Fuel tank removal
3 Side covers removal
4 Headlight removal
Extent of removal Order Part name Q’ty Remarks
SEAT, FUEL TANK AND SIDE
COVERS REMOVAL
Preparation for removal Turn the fuel cock to “OFF”.
Disconnect the fuel hose.
1Seat 1
2 Air scoop (left and right) 2
3 Fitting band 1 Remove on fuel tank side.
4 Bolt (fuel tank) 2
5 Fuel tank 1
6 Side cover (left) 1
Refer to “REMOVAL POINTS”.
7 Side cover (right) 1
8 Headlight coupler 1
9 Headlight 1
31
2
3
4
SEAT, FUEL TANK AND SIDE COVERS

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.
SEAT, FUEL TANK AND SIDE COVERS

4 - 3
ENGEXHAUST PIPE AND SILENCER
EC4S0000
EXHAUST PIPE AND SILENCER
Extent of removal:
1 Silencer removal
2 Exhaust pipe removal
Extent of removal Order Part name Q’ty Remarks
EXHAUST PIPE AND
SILENCER REMOVAL
Preparation for removal Side cover (right) Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Bolt (clamp) 1 Only loosening.
2 Bolt [silencer (front)] 1
3 Bolt [silencer (rear)] 1
4 Silencer 1
5Clamp 1
6 Nut (exhaust pipe) 1
7 Bolt (exhaust pipe) 1
8 Exhaust pipe 1
9 Gasket 2
1
2
2

4 - 5
ENGRADIATOR
EC450001
RADIATOR
Extent of removal:
1 Radiator removal
2 Coolant reservoir removal
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for removal Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Seat, fuel tank and side cover Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
1 Engine guard 1
2 Panel 2
3Clamp 8
4 Radiator (right) 1
5 Hose 2 1
6 Hose 3 1
7 Hose 4 1
8 Pipe 2/O-ring 1/1
9 Radiator breather hose 1
10 Radiator (left) 1
11 Hose 1 1
12 Pipe 1/O-ring 1/1
13 Coolant reservoir hose 1
14 Coolant reservoir tank 1
1
2

4 - 8
ENGCARBURETOR
CARBURETOR
7 4
108 1
9
T R..2 Nm (0.2 m •
kg, 1.4 ft • Ib)
2
3
75
5
T R..4 Nm (0.4 m •
kg, 2.9 ft • Ib)
T R..3 Nm (0.3 m • kg, 2.2 ft • Ib)
6
T R..3 Nm (0.3 m • kg, 2.2 ft • Ib)
1
T R..4 Nm (0.4 m •
kg, 2.9 ft • Ib)
T R..11 Nm (1.1 m •
kg, 8.0 ft • Ib)
Extent of removal:
1 Carburetor removal
Extent of removal Order Part name Q’ty Remarks
CARBURETOR REMOVAL
Preparation for removal Fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Cylinder head breather hose Refer to “CAMSHAFTS” section.
1Clamp 1
2Band 1
3 TPS coupler 1
4 Throttle cable cover 1
5 Throttle cable 2
6 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
7 Clamp (carburetor joint) 2 Loosen the screws (carburetor joint).
8 Hot starter plunger 1
9 Carburetor 1
10 Carburetor joint 1
1

4 - 23
ENGCAMSHAFTS
CAMSHAFTS
CYLINDER HEAD COVER
Extent of removal:
1 Cylinder head cover removal
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD COVER
REMOVAL
Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
1 Spark plug 1
2 Engine upper bracket (right) 1
3 Engine upper bracket (left) 1
4 Cylinder head breather hose 1
5 Oil tank breather hose 1
6 Bolt (cylinder head cover) 2
7 Cylinder head cover 1
8 Cylinder head cover gasket 1
1