2004 YAMAHA WR 450F clutch

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ENGAC MAGNETO AND STARTER CLUTCH
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 ı, 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 Å, 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.
EC4L5000
ASSEMBLY AND INSTALLATION
AC magneto and starter clutch
1. Install:
Stator 1
Bolt (stator) 2
Pick-up coil 3
Bolt (pick-up coil) 4
NOTE:
Pass the AC magneto lead 5 under the pick-
up coil.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

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ENGAC MAGNETO AND STARTER CLUTCH
2. Install:
Holder 1
Bolt 2
NOTE:
Pass the pick-up coil lead 3 and AC mag-
neto lead 4 under the holder as shown.
Take care not to catch the AC magneto lead
between crankcase cover ribs.
Apply the sealant to the grommet of the AC
magneto lead.
Quick gasket:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Install:
Starter clutch drive gear 1
Starter clutch 2
NOTE:
Apply the engine oil on the starter clutch drive
gear inner circumference.
4. 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.
c
2 1 1
ba

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ENG
5. Install:
Bolt (starter clutch) 1
Plain washer (rotor)
Nut (rotor) 2
Use the sheave holder 3.
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).
Sheave holder:
YS-1880-A/90890-01701
1
1
3
2
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..65 Nm (6.5 m · kg, 47 ft · lb)
6. Install:
Shaft 1
Bearing 2
Idle gear 2 3
NOTE:
Apply the engine oil on the shaft, bearing and
idle gear inner circumference.
7. 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)
8. Install:
Plain washer
Torque limiter 1
Plain washer
NOTE:
Apply the engine oil to the shaft and plain
washers.1
AC MAGNETO AND STARTER CLUTCH

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ENG
9. Install:
Cover (idle gear 1) 1
Bolt 2
NOTE:
Install the cover (idle gear 1) with its mark a
facing upward.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
10. Install:
Engine guard 1
Clamp 2
Bolt [engine guard (front)] 3
Bolt [engine guard (rear)] 4
Cylinder head breather hose 5
T R..34 Nm (3.4 m · kg, 24 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)
11. Connect:
AC magneto lead
Refer to “CABLE ROUTING DIA-
GRAM” 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 1 mm (0.04 in) a above the top of the
footrest.
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.
WARNINGSupport the machine securely so there is no
danger of it falling over.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable and guide Disconnect at the engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “AC MAGNETO AND
STARTER CLUTCH” section.
Cylinder head breather hose and
oil tank breather hoseRefer to “CAMSHAFTS” section.
Ignition coil
Disconnect the AC magneto lead.

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ENGENGINE REMOVAL
Extent of removal:1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Crankcase cover (left) Refer to “AC MAGNETO AND
STARTER CLUTCH” section for remov-
ing the starter motor lead.
Disconnect the starter motor
lead.Refer to “ELECTRIC STARTING SYS-
TEM” section in the CHAPTER 6.
Negative battery lead Disconnect at the starter motor side.
1 Engine skid plate (front) 1
2 Neutral switch 1
3 Oil hose 2
4 Chain cover 1
5 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 6 Lock washer 1
7 Drive sprocket 1
8 Clip 1
9 Bolt (brake pedal) 1
10 Brake pedal 1
1

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ENGCRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
Extent of removal:1 Crankcase separation2 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) 6
Refer to “REMOVAL POINTS”. 4 Bolt (60 mm) 3
5 Bolt (75 mm) 3
6 Hose guide 1
7 Clutch cable holder 1
8 Crankcase (right) 1
9 Crankcase (left) 1
21

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ENGCRANKCASE AND CRANKSHAFT
REMOVAL POINTS
Crankcase
1. Separate:
Crankcase (right)
Crankcase (left)
Separation steps:
Remove the crankcase bolts, hose guide
and clutch cable holder.
NOTE:
Loosen each bolt 1/4 of a turn at a time and
after all the bolts are loosened, remove
them.
Remove the crankcase (right).
NOTE:
Place the crankcase with its left side
downward and split it by inserting a screw-
driver tip into the splitting slit a in the
crankcase.
Lift the crankcase (right) horizontally while
lightly patting the case splitting slit and
engine mounting boss using a soft ham-
mer, and leave the crankshaft and trans-
mission with the crankcase (left).
CAUTION:
Use soft hammer to tap on the case half.
Tap only on reinforced portions of case.
Do not tap on gasket mating surface.
Work slowly and carefully. Make sure the
case halves separate evenly. If one end
“hangs up”, take pressure off the push
screw, realign, and start over. If the
cases do not separate, check for a
remaining case screw or fitting. Do not
force.
Remove the dowel pins and O-ring.
a