2007 YAMAHA WR 450F oil

4 - 89
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.

4 - 90
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Cylinder head breather hose Refer to “CAMSHAFTS” section.
Ignition coil
Disconnect the AC magneto 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 guard 1
2 Neutral switch 1
3 Chain cover 1
4 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 5 Lock washer 1
6 Drive sprocket 1
7Clip 1
8 Bolt (brake pedal) 1
9 Brake pedal 1
1

4 - 96
ENGCRANKCASE AND CRANKSHAFT
Extent of removal Order Part name Q’ty Remarks
10 Oil strainer 1
11 Balancer shaft 1 Refer to “REMOVAL POINTS”.
12 Crankshaft 1 Use special tool.
Refer to “REMOVAL POINTS”.
2

4 - 97
ENGCRANKCASE AND CRANKSHAFT
CRANKCASE BEARING
Extent of removal:
1 Crankcase bearing removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE BEARING
REMOVAL
Preparation for removal Transmission Refer to “TRANSMISSION, SHIFT
CAM AND SHIFT FORK” section.
Shift cam and shift fork
1 Oil seal 3
2 Bearing 10 Refer to “REMOVAL POINTS”.
1

4 - 100
ENGCRANKCASE AND CRANKSHAFT
2. Inspect:
Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
3. Inspect:
Oil seal
Wear/damage → Replace.
EC4N4201
Crankshaft
1. Measure:
Runout limit a
Small end free play limit b
Connecting rod big end side clearance c
Crank width d
Out of specification → Replace.
Use the dial gauge and a thickness
gauge.
Dial gauge and stand:
YU-3097/90890-01252
Standard
Runout
limit:0.03 mm
(0.0012 in)0.05 mm
(0.002 in)
Small end
free play:0.4 ~ 1.0 mm
(0.016 ~ 0.039 in)2.0 mm
(0.08 in)
Side
clearance:0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Crack
width:61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)—
Oil strainer
1. Inspect:
Oil strainer
Damage → Replace.

4 - 102
ENGCRANKCASE AND CRANKSHAFT
NOTE:
Hold the connecting rod at top dead center
with one hand while turning the nut of the
installing tool with the other. Operate the
installing tool until the crankshaft bottoms
against the bearing.
Before installing the crankshaft, clean the
contacting surface of crankcase.
CAUTION:
Do not use a hammer to drive in the crank-
shaft.
2. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.
3. Install:
Oil strainer 1
Bolt (oil strainer) 2
4. Apply:
Sealant
On the crankcase (right).
NOTE:
Clean the contacting surface of crankcase (left
and right) before applying the sealant.
YAMAHA Bond No. 1215
(ThreeBond® No. 1215):
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 103
ENGCRANKCASE AND CRANKSHAFT
5. Install:
Dowel pin 1
O-ring 2
Crankcase (right)
To crankcase (left).
NOTE:
Fit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
When installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
New
6. Tighten:
Hose guide 1
Clutch cable holder 2
Bolt (clutch cable holder)
Bolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
7. Install:
Timing chain
Timing chain guide (rear)
Bolt (timing chain guide)
8. Remove:
Sealant
Forced out on the cylinder mating surface.
9. Apply:
Engine oil
To the crank pin, bearing and oil delivery
hole.
10. Check:
Crankshaft and transmission operation.
Unsmooth operation → Repair.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 107
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
ASSEMBLY AND INSTALLATION
Transmission
1. Install:
5th pinion gear (25T) 1
3rd pinion gear (16T) 2
Collar 3
4th pinion gear (20T) 4
2nd pinion gear (15T) 5
To main axle 6.
NOTE:
Apply the molybdenum disulfide oil on the
inner and end surface of the idler gear and on
the inner surface of the sliding gear, then
install.
2. Install:
Collar 1
2nd wheel gear (26T) 2
4th wheel gear (21T) 3
3rd wheel gear (21T) 4
5th wheel gear (21T) 5
Collar 6
1st wheel gear (29T) 7
O-ring 8
To drive axle 9.
NOTE:
Apply the molybdenum disulfide oil on the
inner and end surface of the idler gear and
on the inner surface of the sliding gear, then
install.
Apply the lithium soap base grease on the O-
ring.