2007 YAMAHA WR 450F clutch

4 - 83
ENG
NOTE:
Tighten the rotor nut to 65 Nm (6.5 m  kg, 47 ft  lb), loosen and retighten the rotor nut to 65 Nm
(6.5 m  kg, 47 ft  lb).
Extent of removal Order Part name Q’ty Remarks
7 Idle gear 1
8 Bearing 1
9Shaft 1
10* Nut (rotor) 1 Refer to NOTE.
11 Rotor 1 Use special tool.
Refer to “REMOVAL POINTS”.
12 Woodruff key 1
13 Starter clutch assembly cover 1
Refer to “REMOVAL POINTS”.
14 Starter clutch 1
15 Starter clutch drive gear 1
16 Holder 1
17 Pick-up coil 1
18 Stator 1
3
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AC MAGNETO AND STARTER CLUTCH

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ENGAC MAGNETO AND STARTER CLUTCH
EC4L3000
REMOVAL POINTS
Rotor
1. Remove:
Nut (rotor) 1
Plain washer
Use the sheave holder 2.
Sheave holder:
YS-1880-A/90890-01701
2
1
2. Remove:
Rotor 1
Use the rotor puller 2.
Rotor puller:
YM-04142/90890-04142
Starter clutch
1. Remove:
Starter clutch assembly cover 1
NOTE:
Insert a thin screwdriver or the like under the
convexity a and remove the starter clutch
assembly cover by prying it gently to void dam-
age to the cover.
1
a
2. Remove:
Starter clutch 1
NOTE:
Using a thin screwdriver or the like, remove the
plate a while prying it upward little by little.
1
a
EC4L4000
INSPECTION
AC magneto
1. Inspect:
Rotor inner surface a
Stator outer surface b
Damage → Inspect the crankshaft runout
and crankshaft bearing.
If necessary, replace AC magneto and/or
stator.

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ENGAC MAGNETO AND STARTER CLUTCH
EC4L4200
Woodruff key
1. Inspect:
Woodruff key 1
Damage → Replace.
Starter clutch
1. Check:
Starter clutch
Damage/wear → Replace.
2. Check:
Idle gear
Idle gear shaft
Starter clutch gear
Pitting/burrs/chips/roughness/wear →
Replace the defective parts.
3. Check:
Starter clutch operation
Install the starter clutch drive gear 1 onto
the starter clutch 2 and hold the starter
clutch.
When turning the starter clutch drive gear
counterclockwise É, the starter clutch and
the starter clutch drive gear should
engage. If the starter clutch drive gear and
starter clutch do not engage, the starter
clutch is faulty and must be replaced.
When turning the starter clutch drive gear
clockwise È, it should turn freely.
If the starter clutch drive gear does not
turn freely, the starter clutch is faulty and
must be replaced.
Torque limiter
1. Check:
Torque limiter
Damage/wear → Replace.

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ENGAC MAGNETO AND STARTER CLUTCH
EC4L5000
ASSEMBLY AND INSTALLATION
AC magneto and starter clutch
1. Install:
Stator 1
Bolt (stator) 2
Pick-up coil 3
Holder 4
Bolt 5
NOTE:
Pass the AC magneto lead 5 under the pick-
up coil.
Pass the AC magneto lead 4 under the
holder as shown.
Take care not to catch the AC magneto lead
between crankcase cover ribs.
Tighten the bolt (stator) using the T25 bit.
Apply the sealant to the grommet of the AC
magneto lead.
YAMAHA Bond No. 1215
(ThreeBond® No. 1215):
90890-85505
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
2. Install:
Starter clutch drive gear 1
NOTE:
Apply the engine oil on the starter clutch drive
gear inner circumference.

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ENG
3. Install:
Starter clutch 1
To rotor 2.
NOTE:
Install the starter clutch with its plate side
upward.
While installing the starter clutch, push in the
projections a one by one on the clutch cir-
cumference.
Push in the starter clutch until it hits the rotor.
4. Install:
Starter clutch assembly cover 1
To rotor 2.
NOTE:
Install the starter clutch assembly cover by fit-
ting its pawls a into the groove b in the rotor.
1
2a
1
2a
b
5. Install:
Woodruff key 1
Rotor 2
NOTE:
Degrease the contact surfaces of 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.
6. Install:
Plain washer (rotor)
Nut (rotor) 1
Use the sheave holder 2.
NOTE:
Tighten the rotor nut to 65 Nm (6.5 m  kg,
47 ftlb), loosen and retighten the rotor nut to
65 Nm (6.5 m  kg, 47 ft  lb).
Sheave holder:
YS-1880-A/90890-01701
2
1
T R..65 Nm (6.5 m · kg, 47 ft · lb)
AC MAGNETO AND STARTER CLUTCH

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ENG
7. Install:
Shaft 1
Bearing 2
Idle gear 2 3
NOTE:
Apply the engine oil on the shaft, bearing and
idle gear inner circumference.
8. Install:
Dowel pin
Gasket [crankcase cover (left)]
Crankcase cover (left) 1
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)
9. Install:
Plain washer
Torque limiter 1
Plain washer
NOTE:
Apply the engine oil to the shaft and plain
washers.1
10. Install:
Cover (idle gear 1) 1
Bolt 2
NOTE:
Install the cover (idle gear 1) with its mark a
facing upward.
11. Connect:
AC magneto lead
Refer to “CABLE ROUTING DIAGRAM”
section in the CHAPTER 2.
12. Install:
Shift pedal 1
Bolt (shift pedal)
NOTE:
When installing the shift pedal onto the shift
shaft, be sure that the center of the shift pedal
is about 5.1 mm (0.2 in) a above the top of the
footrest.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
AC MAGNETO AND STARTER CLUTCH

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ENGENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is nodanger of it falling over.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Seat, fuel tank and side cover Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Radiator Refer to “RADIATOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Air cut-off valve assembly Refer to “AIR INDUCTION SYSTEM”
section.
Clutch cable and guide Disconnect at the engine side.
Shift pedal Refer to “AC MAGNETO AND
STARTER CLUTCH” section.
Rear shock absorber Refer to “REAR SHOCK ABSORBER”
section in the CHAPTER 6
Carburetor Refer to “CARBURETOR” section.

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ENGCRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
Extent of removal:
1 Crankcase separation
2 Crankshaft removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE SEPARATION
Preparation for removal Engine Refer to “ENGINE REMOVAL” section.
Piston Refer to “CYLINDER AND PISTON” sec-
tion.
Balancer Refer to “BALANCER” section.
Kick axle assembly
Refer to “KICK AXLE AND SHIFT
SHAFT” section.
Segment
Stator Refer to “AC MAGNETO AND
STARTER CLUTCH” section.
1 Timing chain guide (rear) 1
2 Timing chain 1
3 Bolt (50 mm) 7
Refer to “REMOVAL POINTS”. 4 Bolt (60 mm) 2
5 Bolt (80 mm) 3
6 Hose guide 1
7 Clutch cable holder 1
8 Crankcase (right) 1
9 Crankcase (left) 1
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