2006 YAMAHA YZ450F key

EC080000
HOW TO USE
THIS MANUAL
EC081000
PARTICULARLY IMPORTANT
INFORMATION
The Safety Alert Symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS
INVOLVED!
Failure to follow WARNING instructions could
result in severe injury or death to the machine
operator, a bystander, or a person inspecting
or repairing the machine.
A CAUTION indicates special precautions that
must be taken to avoid damage to the
machine.
NOTE:
A NOTE provides key information to make pro-
cedures easier or clearer.
WA R N I N G
CAUTION:
EC082000
FINDING THE REQUIRED PAGE
1. This manual consists of seven chapters;
“General Information”, “Specifications”,
“Regular inspection and adjustments”,
“Engine”, “Chassis”, “Electrical” and “Tun-
ing”.
2. The table of contents is at the beginning of
the manual. Look over the general layout of
the book before finding then required chap-
ter and item.
Bend the book at its edge, as shown, to
find the required fore edge symbol mark
and go to a page for required item and
description.

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)

4 - 63
ENGBALANCER
BALANCER
BALANCER
Extent of removal:
1 Balancer drive gear
2 Balancer
Extent of removal Order Part name Q’ty Remarks
BALANCER REMOVAL
Preparation for removal Clutch housing Refer to “CLUTCH” section.
Crankcase cover (right) Refer to “OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT)” section.
Stator Refer to “CDI MAGNETO” section.
1 Nut (balancer) 1
Refer to “REMOVAL POINTS”. 2 Nut (primary drive gear) 1
3 Nut (balancer driven gear) 1
4 Lock washer 1
5 Balancer 1
6 Straight key 1
7 Conical washer 1
8 Primary drive gear 1
9 Balancer drive gear 1
10 Lock washer 1
11 Balancer driven gear 1
2
1
2
1

4 - 65
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
Balancer driven gear 1
NOTE:
Install the balancer driven gear and balancer
shaft with their lower splines a aligning with
each other.
2. Install:
Balancer drive gear 1
NOTE:
Align the punched mark a on the balancer
drive gear with the punched mark b on the
balancer driven gear.
Install the balancer driven gear and crank-
shaft with the lower splines c aligning with
each other.
3. Install:
Lock washer 1
Nut (balancer driven gear) 2
Primary drive gear 3
Conical washer 4
Nut (primary drive gear) 5
Straight key 6
Balancer 7
Lock washer 8
Nut (balancer) 9
NOTE:
Apply engine oil to the contact surface and
threaded portion of the nut (primary drive
gear).
Place an aluminum plate a between the
teeth of the balancer drive gear 0 and bal-
ancer driven gear A.
Install the primary drive gear with its weight
reduction holes b facing the engine.
Install the conical washer with its convex sur-
face c outward.
4. Bend the lock washer tab.
a 0
1A
2
T R..50 Nm (5.0 m · kg, 36 ft · lb)
E
A
0a
c b
5
4
3
T R..110 Nm (11.0 m · kg, 80 ft · lb)
T R..45 Nm (4.5 m · kg, 33 ft · lb)

4 - 78
ENGCDI MAGNETO
EC4L0000
CDI MAGNETO
Extent of removal:1 CDI magneto removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO REMOVAL
Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Disconnect the CDI magneto lead.
1 Crankcase cover (left) 1
2 Gasket 1
3 Dowel pin 2
4 Nut (rotor) 1 Use special tool.
Refer to “REMOVAL POINTS”.
5 Rotor 1
6 Stator 1
7 Woodruff key 1
1

4 - 79
ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
EC4L3101
Rotor
1. Remove:
Nut (rotor) 1
Plain washer
2. Remove:
Rotor 1
Use the rotor puller 2.
Rotor puller:
YM-04151/90890-04151
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
Rotor inner surface a
Stator outer surface b
Damage → Inspect the crankshaft runout
and crankshaft bearing.
If necessary, replace CDI magneto and/
or stator.
EC4L4200
Woodruff key
1. Inspect:
Woodruff key 1
Damage → Replace.
EC4L5000
ASSEMBLY AND INSTALLATION
CDI magneto
1. Install:
Stator 1
Screw (stator) 2
NOTE:
Apply the sealant to the grommet of the CDI
magneto lead.
Tighten the screws using the T30 bit.
YAMAHA Bond No. 1215
(ThreeBond® No. 1215):
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 80
ENGCDI MAGNETO
2. Install:
Woodruff key 1
Rotor 2
NOTE:
Clean the tapered portions of the crankshaft
and rotor.
When installing the woodruff key, make sure
that its flat surface a is in parallel with the
crankshaft center line b.
When installing the rotor, align the keyway c
of the rotor with the woodruff key.
3. Install:
Plain washer
Nut (rotor) 1
T R..56 Nm (5.6 m · kg, 40 ft · lb)
4. Connect:
CDI magneto lead
Refer to “CABLE ROUTING DIAGRAM”
section in the CHAPTER 2.
5. Install:
Dowel pin
O-ring
Gasket [crankcase cover (left)]
Crankcase cover (left) 1
Hose holder (cylinder head breather
hose) 2
Bolt [crankcase cover (left)]
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)