Yamaha Wr 450 F Owners Manual

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ENGAC MAGNETO AND STARTER CLUTCH
EC4L3000
REMOVAL POINTS
Rotor
1. Remove:
Nut (rotor) 1 
Plain washer
2. Remove:
Rotor 1 
Use the rotor puller 2.
Rotor puller:
YM-04141/90890-04141
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.
EC4L4200
Woodruff key
1. Inspect:
Woodruff key 1 
Damage → Replace. 

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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...

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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:
Plain washer 1 
Bearing 2 
Starter clutch drive gear 3 
Starter clutch 4 
NOTE:
Apply the engine oil...

 
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ENG
 
5. Install: 
 
Bolt (starter clutch)   
1  
  
 
Plain washer (rotor) 
 
Nut (rotor)   
2  
 
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).
6. Install: 
 
Shaft   
1  
  
 
Bearing   
2  
  
 
Idle gear 2   
3  
 
NOTE:
 
Apply the engine oil on the shaft, bearing and 
idle gear inner circumference.
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..65 Nm (6.5 m · kg, 47 ft · lb)
 
7. Install: 
 
Dowel pin 
...

 
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ENG
 
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...

 
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ENG
 
ENGINE 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 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...

 
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ENG
 
ENGINE 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...

 
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ENG
 
ENGINE REMOVAL 
Extent of removal Order Part name Q’ty Remarks
11 Engine upper bracket (right) 1
12 Engine upper bracket (left) 1
13 Engine lower bracket 2
14 Engine mounting bolt 3
15 Pivot shaft 1
Refer to “REMOVAL POINTS”.
16Engine
1
1 

 
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ENG
 
ENGINE REMOVAL 
EC4M3000 
REMOVAL POINTS 
EC4F3100 
Drive sprocket 
1. Remove: 
 
Nut (drive sprocket) 1 
Lock washer 2 
NOTE:
Straighten the lock washer tab.
Loosen the nut while applying the rear brake.
2. Remove:
Drive sprocket 1 
Drive chain 2 
NOTE:
Remove the drive sprocket together with the
drive chain.
EC4M3301
Engine removal
1. Remove:
Pivot shaft 1 
NOTE:
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar...

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ENGENGINE REMOVAL
EC4M5000
ASSEMBLY AND INSTALLATION
Engine installation
1. Install:
Engine 1 
Install the engine from right side.
Pivot shaft 2 
Engine mounting bolt (lower) 3 
Engine lower bracket 4 
Bolt (engine bracket) 5 
Engine mounting bolt (front) 6 
Engine upper bracket (right) 7 
Engine upper bracket (left) 8 
Bolt (engine bracket) 9 
Engine mounting bolt (upper) 0 
Bolt (engine guard) A 
Engine skid plate (front) B 
Bolt (engine skid plate) C 
NOTE:
Apply the molybdenum...