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SPEC
2 - 1
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: WR450FV (USA, CDN, AUS, NZ)
WR450F (EUROPE, ZA)
Model code number: 5TJB (USA)
5TJC (EUROPE)
5TJD (CDN, AUS, NZ, ZA)
Dimensions: USA, ZA, CDN EUROPE, AUS, NZ
Overall length 2,200 mm (86.61 in) 2,195 mm (86.42 in)
Overall width 830 mm (32.68 in)←
Overall height 1,295 mm (50.98 in)←
Seat height 985 mm (38.78 in) 990 mm (38.98 in)
Wheelbase 1,490 mm (58.66 in)←
Minimum ground clearance 370 mm (14.57 in)←
Dry weight:
Without oil and fuel 113.0 kg (249.1 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 449 cm
3 (15.8 Imp oz, 15.2 US oz)
Bore × stroke 95.0 × 63.4 mm (3.74 × 2.50 in)
Compression ratio 12.3 : 1
Starting system Kick and electric starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil (For USA and CDN)
At 5 °C (40 °F) or higher È
Yamalube 4 (20W-40) or SAE 20W-40 type SG
motor oil (Non-Friction modified)
At 15 °C (60 °F) or lower É
Yamalube 4 (10W-30) or SAE 10W-30 type SG
motor oil (Non-Friction modified) and/or
Yamalube 4-R (15W-50) (Non-Friction modi-
fied)
(Except for USA and CDN)
API “SG” or higher grade
-20
-4-10
140
3010
5020
6830
8640 50
104
122˚CTemp.
˚F
10W-30
10W-40
20W-40
20W-50
15W-40
GENERAL SPECIFICATIONS
Page 94 of 786

SPEC
2 - 5 Cam chain:
Cam chain type/No. of links 98XRH2010-118M/118 ----
Cam chain adjustment method Automatic ----
Valve, valve seat, valve guide:
Valve clearance (cold) IN 0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)----
EX 0.20 ~ 0.25 mm
(0.0079 ~ 0.0098 in)----
Valve dimensions:
“A” head diameter IN 26.9 ~ 27.1 mm
(1.0591 ~ 1.0669 in)----
EX 27.9 ~ 28.1 mm
(1.0984 ~ 1.1063 in)----
“B” face width IN 2.26 mm (0.089 in) ----
EX 2.26 mm (0.089 in) ----
“C” seat width IN 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
EX 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
“D” margin thickness IN 1 mm (0.0394 in) 0.85 mm
(0.033 in)
EX 1 mm (0.0394 in) 0.85 mm
(0.033 in)
Stem outside diameter IN 4.475 ~ 4.490 mm
(0.1762 ~ 0.1768 in)4.445 mm
(0.1750 in)
EX 4.965 ~ 4.980 mm
(0.1955 ~ 0.1961 in)4.935 mm
(0.1943 in)
Guide inside diameter IN 4.500 ~ 4.512 mm
(0.1772 ~ 0.1776 in)4.550 mm
(0.1791 in)
EX 5.000 ~ 5.012 mm
(0.1969 ~ 0.1973 in)5.050 mm
(0.1988 in)
Stem-to-guide clearance IN 0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)0.08 mm
(0.003 in)
EX 0.020 ~ 0.047 mm
(0.0008 ~ 0.0019 in)0.10 mm
(0.004 in)
Stem runout limit ---- 0.01 mm
(0.0004 in) Item Standard Limit
BC
DA
Head Diameter Face Width Seat Width Margin Thickness
MAINTENANCE SPECIFICATIONS
Page 96 of 786

SPEC
2 - 7 Piston rings:
Top ring:
Type Barrel ----
Dimensions (B × T) 1.2 × 3.5 mm (0.05 × 0.14 in) ----
End gap (installed) 0.20 ~ 0.30 mm
(0.008 ~ 0.012 in)0.55 mm
(0.022 in)
Side clearance (installed) 0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)0.12 mm
(0.005 in)
2nd ring:
Type Taper ----
Dimensions (B × T) 1.00 × 3.35 mm (0.04 × 0.13 in) ----
End gap (installed) 0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)0.85 mm
(0.033 in)
Side clearance 0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)0.12 mm
(0.005 in)
Oil ring:
Dimensions (B × T) 2.0 × 2.9 mm (0.08 × 0.11 in) ----
End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----
Crankshaft:
Crank width “A”61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)----
Runout limit “C”0.03 mm (0.0012 in) 0.05 mm
(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 mm
(0.08 in)
Balancer:
Balancer drive method Gear ----
Air filter oil grade: Foam-air-filter oil or equivalent
oil ---- Item Standard Limit
T
B
B
T
B
T
MAINTENANCE SPECIFICATIONS
Page 98 of 786
SPEC
2 - 9 Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance “A”0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Tip clearance “B”0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Side clearance “C”0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.007 in)
Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm
2,
5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width 117.8 mm (4.6 in) ----
Height 260 mm (10.2 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.71 L (0.62 Imp qt, 0.75 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
MAINTENANCE SPECIFICATIONS
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4 - 27
ENGCAMSHAFTS
4. Measure:
Camshaft-to-cap clearance
Out of specification → Measure camshaft
journal diameter.
Camshaft-to-cap clearance:
0.028 ~ 0.062 mm
(0.0011 ~ 0.0024 in)
: 0.08 mm (0.003 in)
Measurement steps:
Install the camshaft onto the cylinder
head.
Position a strip of Plastigauge
® 1 onto the
camshaft.
Install the circlip, dowel pins and camshaft
caps.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m kg, 7.2 ft lb)
NOTE:
Tighten the bolts (camshaft cap) in a criss-
cross pattern from innermost to outer
caps.
Do not turn the camshaft when measuring
clearance with the Plastigauge®.
Remove the camshaft caps and measure
the width of the Plastigauge
® 1.
5. Measure:
Camshaft journal diameter a
Out of specification → Replace the cam-
shaft.
Within specification → Replace camshaft
case and camshaft caps as a set.
Camshaft sprocket
1. Inspect:
Camshaft sprocket 1
Wear/damage → Replace the camshaft
assembly and timing chain as a set.
Camshaft journal diameter:
21.959 ~ 21.972 mm
(0.8645 ~ 0.8650 in)
Page 390 of 786
4 - 37
ENGVALVES AND VALVE SPRINGS
REMOVAL POINTS
Valve lifter and valve cotter
1. Remove:
Valve lifters 1
Pads 2
NOTE:
Identify each lifter 1 and pad 2 position very
carefully so that they can be reinstalled in their
original place.
2. Check:
Valve sealing
Leakage at the valve seat → Inspect the
valve face, valve seat and valve seat
width.
Checking steps:
Pour a clean solvent 1 into the intake and
exhaust ports.
Check that the valve seals properly.
There should be no leakage at the valve
seat 2.
3. Remove:
Valve cotters
NOTE:
Attach a valve spring compressor 1 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
Valve spring compressor:
YM-4019/90890-04019
Page 396 of 786

4 - 40
ENGVALVES AND VALVE SPRINGS
5. Measure:
Runout (valve stem)
Out of specification → Replace.
NOTE:
When installing a new valve always replace
the guide.
If the valve is removed or replaced always
replace the oil seal.
6. Eliminate:
Carbon deposits
(from the valve face and valve seat)
7. Inspect:
Valve seats
Pitting/wear → Reface the valve seat.
Runout limit:
0.01 mm (0.0004 in)
8. Measure:
Valve seat width a
Out of specification → Reface the valve
seat.
Valve seat width:
Intake:
0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Exhaust:
0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Measurement steps:
Apply Mechanic’s blueing dye (Dykem) b
to the valve face.
Install the valve into the cylinder head.
Press the valve through the valve guide
and onto the valve seat to make a clear
pattern.
Measure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
If the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat
must be refaced.
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4 - 41
ENGVALVES AND VALVE SPRINGS
9. Lap:
Valve face
Valve seat
NOTE:
After refacing the valve seat or replacing the
valve and valve guide, the valve seat and
valve face should be lapped.
Lapping steps:
Apply a coarse lapping compound to the
valve face.
CAUTION:
Do not let the compound enter the gap
between the valve stem and the guide.
Apply molybdenum disulfide oil to the
valve stem.
Install the valve into the cylinder head.
Turn the valve until the valve face and
valve seat are evenly polished, then clean
off all of the compound.
NOTE:
For best lapping results, lightly tap the valve
seat while rotating the valve back and forth
between your hands.
Apply a fine lapping compound to the
valve face and repeat the above steps.
NOTE:
After every lapping operation be sure to
clean off all of the compound from the valve
face and valve seat.
Apply Mechanic’s blueing dye (Dykem) to
the valve face.
Install the valve into the cylinder head.
Press the valve through the valve guide
and onto the valve seat to make a clear
pattern.
Measure the valve seat width again. If the
valve seat width is out of specification,
reface and relap the valve seat.