width YAMAHA WR 450F 2011 Owners Manual

2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name: WR450FA (USA, CDN, AUS, NZ)WR450F (EUROPE, ZA)
Model code number: 1HB1 (USA) 1HB2 (CDN)
1HB3 (EUROPE)
1HB4 (AUS, NZ, ZA)
Dimensions: USA, CDN, ZA EUROPE AUS, NZ
Overall length 2,175 mm (85.63 in)2,200 mm (86.61
in)2,185 mm (86.02
in)
Overall width 825 mm (32.48 in) ←←
Overall height 1,300 mm (51.18 in)1,305 mm (51.38
in)←
Seat height 980 mm (38.58 in) 990 mm (38.98 in) 985 mm (38.78 in)
Wheelbase 1,485 mm (58.46 in)1,500 mm (59.06
in)1,485 mm (58.46
in)
Minimum ground clearance 365 mm (14.37 in) ←←
Weight: USACDN, EUROPE, AUS, NZ,
ZA
With oil and fuel 121 kg (267 lb) 122 kg (270 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 Recommended brand: YAMALUBE SAE 10W-30, SAE 10W-40, SAE 10W-50,
SAE 15W-40, SAE 20W-40 or SAE 20W-50
API service SG type or higher,
JASO standard MA
Oil capacity: Engine oilPeriodic oil change 0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement 1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 1.0 L (0.88 Imp qt, 1.06 US qt)
Air filter: Wet type element

2-4
MAINTENANCE SPECIFICATIONS
Intake "A" 30.100–30.200 mm (1.1850–1.1890 in) 30.000 mm
(1.1811 in)
Intake "B" 22.450–22.550 mm (0.8839–0.8878 in) 22.350 mm
(0.8799 in)
Exhaust "A" 30.200–30.300 mm (1.1890–1.1929 in) 30.100 mm
(1.1850 in)
Exhaust "B" 22.450–22.550 mm (0.8839–0.8878 in) 22.350 mm
(0.8799 in)
Camshaft runout limit ---- 0.03 mm
(0.0012 in)
Timing chain:
Timing chain type/No. of links 98XRH2010-118M/118 ----
Timing 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) ----
"A" head diameter (EX) 27.9–28.1 mm (1.0984–1.1063 in) ----
"B" face width (IN) 2.26 mm (0.089 in) ----
"B" face width (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)
"C" seat width (EX) 0.9–1.1 mm (0.0354–0.0433 in) 1.6 mm (0.0630
in) Item Standard Limit

2-7
MAINTENANCE SPECIFICATIONS
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 ----
Clutch:
Friction plate thickness 2.92–3.08 mm (0.115–0.121 in) 2.8 mm (0.110
in)
Quantity 8 ----
Clutch plate 1 thickness 1.9–2.1 mm (0.075–0.083 in) ----
Quantity 4 ----
Warp limit ---- 0.1 mm (0.004
in)
Clutch plate 2 thickness 1.5–1.7 mm (0.059–0.067 in) ----
Quantity 3 ----
Warp limit ---- 0.1 mm (0.004
in)
Clutch spring free length 50.0 mm (1.97 in) 49.0 mm (1.93
in)
Quantity 6 ----
Clutch housing thrust clearance 0.10–0.35 mm (0.0039–0.0138 in) ----
Clutch housing radial clearance 0.010–0.044 mm (0.0004–0.0017 in) ----
Clutch release method Inner push, cam push ----
Shifter:
Shifter type Cam drum and guide bar ----
Guide bar bending limit ---- 0.05 mm (0.002
in)
Kickstarter:
Type Ratchet type ----Item Standard Limit

2-8
MAINTENANCE SPECIFICATIONS
Carburetor: USA, CDN, AUS,
NZ, ZAEUROPE
I. D. mark 5TJE E0 5TJL L0 ----
Main jet (M.J) #162 #160 ----
Main air jet (M.A.J) ø2.0←----
Jet needle (J.N) NFNT NNHU ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #45 #48 ----
Pilot air jet (P.A.J) #70←----
Pilot outlet (P.O) ø0.9←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #65←----
Leak jet (Acc.P) #60←----
Float height (F.H) 8 mm (0.31 in)←----
Engine idle speed 1,750–1,950 r/min←----
Intake vacuum 34.8–40.1 kPa
(261–301 mmHg,
10.28–11.85 inHg)←----
Hot starter lever free play 3–6 mm (0.12–0.24
in)←----
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 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 120.2 mm (4.73 in) ----
Height (Left/Right) 260 mm (10.24 in)/240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.57 L (0.50 Imp qt, 0.60 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

5-18
CAMSHAFTS
3. Measure:
• Runout (camshaft)
Out of specification→Replace.
4. Measure:
• Camshaft-to-cap clearance
Out of specification→Measure
camshaft outside diameter.
Measurement steps:
a. Install the camshaft onto the cylin-
der head.
b. Position a strip of Plastigauge
®
"1" onto the camshaft.
c. Install the clip, dowel pins and
camshaft caps.
• Tighten the bolts (camshaft cap) in
a crisscross pattern from innermost
to outer caps.
• Do not turn the camshaft when
measuring clearance with the
Plastigauge
®.
d. Remove the camshaft caps and
measure the width of the Plasti-
gauge
® "1".
5. Measure:
• Camshaft outside diameter "a"
Out of specification→Replace the
camshaft.
Within specification→Replace
camshaft case and camshaft
caps as a set.
CHECKING THE CAMSHAFT
SPROCKET
1. Inspect:
• Camshaft sprocket "1"
Wear/damage→Replace the
camshaft assembly and timing
chain as a set.CHECKING THE
DECOMPRESSION SYSTEM
1. Check:
• Decompression system
Checking steps:
a. Check that the decompression
mechanism cam "1" moves
smoothly.
b. Check that the decompression
mechanism cam lever pin "2" proj-
ects from the camshaft.
CHECKING THE TIMING CHAIN
TENSIONER
1. Check:
• While pressing the tensioner rod
lightly with fingers, use a thin
screwdriver "1" and wind the ten-
sioner rod up fully clockwise.
• When releasing the screwdriver
by pressing lightly with fingers,
make sure that the tensioner rod
will come out smoothly.
• If not, replace the tensioner as-
sembly. Runout (camshaft):
Less than 0.03 mm
(0.0012 in)
Camshaft-to-cap clear-
ance:
0.028–0.062 mm
(0.0011–0.0024 in)
:0.08 mm (0.003
in)
Bolt (camshaft cap):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Camshaft outside diame-
ter:
21.959–21.972 mm
(0.8645–0.8650 in)

5-24
VALVES AND VALVE SPRINGS
REMOVING THE VALVE LIFTER
AND VALVE COTTER
1. Remove:• Valve lifter "1"
• Pad "2"
Identify each lifter "1" and pad "2" po-
sition very carefully so that they can
be reinstalled in their original place.
2. Check:• Valve sealingLeakage at the valve seat →In-
spect the valve face, valve seat
and valve seat width.
Checking steps:
a. Pour a clean solvent "1" into the intake and exhaust ports.
b. Check that the valve seals prop- erly.
There should be no leakage at the
valve seat "2".
3. Remove:• Valve cotter
Attach a valve spring compressor "1"
between the valve spring retainer and
the cylinder head to remove the valve
cotters.
CHECKING THE VALVE
1. Measure:
• Stem-to-guide clearance
Out of specification →Replace the
valve guide.
2. Replace: • Valve guide
Replacement steps:
To ease guide removal, installation
and to maintain correct fit heat the
cylinder head in an over to 100 °C
(212 °F).
a. Remove the valve guide using a valve guide remover "1". b. Install the new valve guide using a
valve guide remover "1" and valve
guide installer "2".
c. After installing the valve guide, bore the valve guide using a valve
guide reamer "3" to obtain proper
stem-to-guide clearance.
After replacing the valve guide reface
the valve seat.
Valve spring compres-
sor:YM-4019/90890-04019
Stem-to-guide clearance = valve guide inside diameter "a" -
valve stem diameter "b"
Clearance (stem to
guide):Intake:0.010–0.037 mm
(0.0004–0.0015 in)
:0.08 mm
(0.003 in)
Exhaust:
0.020–0.047 mm
(0.0008–0.0019 in)
:0.10 mm
(0.004 in)Valve guide installation
height "a": Intake:
10.3–10.7 mm
(0.41–0.42 in)
Exhaust:
10.3–10.7 mm
(0.41–0.42 in)
Valve guide remover: Intake:4.5 mm (0.18 in)YM-4116/90890-04116
Exhaust:5.0 mm (0.20
in) YM-4097/90890-04097
Valve guide installer:
Intake:YM-4117/90890-04117
Exhaust:
YM-4098/90890-04098
Valve guide reamer: Intake:4.5 mm (0.18 in)
YM-4118/90890-04118
Exhaust:5.0 mm (0.20
in)
YM-4099/90890-04099

5-25
VALVES AND VALVE SPRINGS
3. Inspect:• Valve facePitting/wear →Grind the face.
• Valve stem end
Mushroom shape or diameter
larger than the body of the stem →
Replace.
4. Measure: • Margin thickness "a"Out of specification →Replace.
5. Measure: • Runout (valve stem)
Out of specification →Replace.
• 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 seatPitting/wear →Reface the valve
seat.
8. Measure: • Valve seat width "a"Out of specification →Reface the
valve seat.
Measurement steps:
a. Apply Mechanic's blueing dye (Dykem) "b" to the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve
guide and onto the valve seat to
make a clear pattern.
d. Measure the valve seat width.
Where the valve seat and valve
face made contact, blueing will
have been removed.
e. If the valve seat is too wide, too narrow, or the seat is not cen-
tered, the valve seat must be
refaced.
9. Lap: • Valve face
• Valve seat
This model uses titanium intake
and exhaust valves. Titanium
valves that have been used to lap
the valve seats must not be used.
Always replace lapped valves with
new valves.
• When replacing the cylinder head, replace the valves without lapping
the valve seats and valve faces. • When replacing the valves or valve
guides, use new valves to lap the
valve seats, and then replace them
with new valves.
Lapping steps:
a. Apply a coarse lapping compound to the valve face.
Do not let the co mpound enter the
gap between the valve stem and
the guide.
b. Apply molybdenum disulfide oil to
the valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face
and valve seat are evenly pol-
ished, then clean off all of the
compound.
For best lapping results, lightly tap
the valve seat while rotating the valve
back and forth between your hands.
e. Apply a fine lapping compound to the valve face and repeat the
above steps.
After every lapping operation be sure
to clean off all of the compound from
the valve face and valve seat.
f. Apply Mechanic's blueing dye (Dykem) to the valve face.
g. Install the valve into the cylinder
head.
Margin thickness:
Intake:1.0 mm (0.039 in)
:0.85 mm
(0.033 in)
Exhaust: 1.0 mm (0.039 in)
:0.85 mm
(0.033 in)
Runout limit: 0.01 mm (0.0004 in)
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)

5-26
VALVES AND VALVE SPRINGS
h. Press the valve through the valve
guide and onto the valve seat to
make a clear pattern.
i. Measure the valve seat width
again. If the valve seat width is out
of specification, reface and relap
the valve seat.
CHECKING THE VALVE SPRINGS
1. Measure:
• Valve spring free length "a"
Out of specification→Replace.
2. Measure:
• Compressed spring force "a"
Out of specification→Replace.
b. Installed length
3. Measure:
• Spring tilt "a"
Out of specification→Replace.CHECKING THE VALVE LIFTERS
1. Inspect:
• Valve lifter
Scratches/damage→Replace
both lifters and cylinder head.
INSTALLING THE VALVES
1. Apply:
• Molybdenum disulfide oil
Onto the valve stem and valve
stem seal.
2. Install:
• Valves "1"
• Valve spring seats "2"
• Valve stem seals "3"
• Valve springs "4"
• Valve spring retainers "5"
• Make sure that each valve is in-
stalled in its original place, also re-
ferring to the painted color as
follows.
Intake (middle) "a": blue
Intake (right/left) "b": gray
Exhaust "c": brown
• Install the valve springs with the
larger pitch "d" facing upward.
e. Smaller pitch
3. Install:
• Valve cotters
While compressing the valve spring
with a valve spring compressor "1" in-
stall the valve cotters.
4. To secure the valve cotters onto
the valve stem, lightly tap the
valve tip with a piece of wood.
Hitting the valve tip with excessive
force could damage the valve.
5. Install:
• Adjusting pad "1"
• Valve lifter "2"
• Apply the molybdenum disulfide oil
on the valve stem end.
• Apply the engine oil on the valve lift-
ers.
• Valve lifter must turn smoothly
when rotated with a finger.
• Be careful to reinstall valve lifters
and pads in their original place.
Free length (valve
spring):
Intake:
39.46 mm (1.55 in)
: 38.46 mm
(1.51 in)
Exhaust:
37.61 mm (1.48 in)
: 36.61 mm
(1.44 in)
Compressed spring
force:
Intake:
130.2–149.8 N at 27.87
mm (13.28–15.28 kg at
27.87 mm, 29.27–
33.68 lb at 1.10 in)
Exhaust:
123.1–141.7 N at 28.38
mm (12.55–14.45 kg at
28.38 mm, 27.67–
31.85 lb at 1.12 in)
Spring tilt limit:
Intake:
2.5°/1.7 mm (0.067 in)
Exhaust:
2.5°/1.6 mm (0.063 in)
Valve spring compres-
sor:
YM-4019/90890-04019

5-36
OIL FILTER ELEMENT AND WATER PUMP
REMOVING THE IMPELLER
SHAFT
1. Remove:
• Impeller "1"
• Washer "2"
• Impeller shaft "3"
Hold the impeller shaft on its width
across the flats "a" with spanners,
etc. and remove the impeller.
REMOVING THE OIL SEAL
It is not necessary to disassemble the
water pump, unless there is an abnor-
mality such as excessive change in
coolant level, discoloration of coolant,
or milky transmission oil.
1. Remove:
• Bearing "1"
• Oil seal "2"CHECKING THE IMPELLER SHAFT
1. Inspect:
• Impeller shaft "1"
Bend/wear/damage→Replace.
Fur deposits→Clean.
CHECKING THE BEARING
1. Inspect:
•Bearing
Rotate inner race with a finger.
Rough spot/seizure→Replace.
CHECKING THE OIL SEAL
1. Inspect:
• Oil seal "1"
Wear/damage→Replace.
INSTALLING THE OIL SEAL
1. Install:
• Oil seal "1"
• Apply the lithium soap base grease
on the oil seal lip.
• Install the oil seal with its manufac-
ture's marks or numbers facing the
right crankcase cover "2".
2. Install:
•Bearing "1"
Install the bearing by pressing its out-
er race parallel.
INSTALLING THE IMPELLER
SHAFT
1. Install:
• Impeller shaft "1"
• Washer "2"
• Impeller "3"
• Take care so that the oil seal lip is
not damaged or the spring does not
slip off its position.
• When installing the impeller shaft,
apply the engine oil on the oil seal
lip, bearing and impeller shaft. And
install the shaft while turning it.
• Hold the impeller shaft on its width
across the flats "a" with spanners,
etc. and install the impeller.
INSTALLING THE RIGHT
CRANKCASE COVER
1. Install:
• Dowel pin "1"
• O-ring "2"
•Collar "3"
• Gasket "4"
Apply the lithium soap base grease
on the O-ring.
Impeller:
14 Nm (1.4 m•kg, 10
ft•lb)

5-61
CRANKCASE AND CRANKSHAFT
CHECKING THE 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 thick-
ness gauge.
CHECKING THE OIL STRAINER
1. Inspect:
• Oil strainer
Damage→Replace.INSTALLING THE CRANKCASE
BEARING
1. Install:
•Bearing
• Bearing stopper
• Bolt (bearing stopper)
• Screw (bearing stopper)
• Screw [bearing stopper (crank-
shaft)] "1"
To left and right crankcase.
• Install the bearing by pressing its
outer race parallel.
• To prevent the screw [bearing stop-
per (crankshaft)] from becoming
loose, crush the screw head periph-
ery "a" into the concave "b" using a
punch etc. In so doing, take care
not to damage the screwdriver re-
ceiving hole in the screw head.
INSTALLING THE CRANKSHAFT
1. Install:
• Crankshaft "1"
Use the crankshaft installing tool
"2", "3", "4" and "5".
• 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 un-
til the crankshaft bottoms against
the bearing.
• Before installing the crankshaft,
clean the contacting surface of
crankcase.
Do not use a hammer to drive in
the crankshaft.
A. For USA and CDN
B. Except for USA and CDN
2. Check:
• Shifter operation
• Transmission operation
Unsmooth operation→Repair.
3. Install:
• Oil strainer "1"
• Bolt (oil strainer) "2" 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
clear-
ance: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)—
Bolt (bearing stopper):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Screw (bearing stopper):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Screw [bearing stopper
(crankshaft)]:
14 Nm (1.4 m•kg, 1.0
ft•lb)
Crankshaft installing pot
"2":
YU-90050/90890-01274
Crankshaft installing bolt
"3":
YU-90050/90890-01275
Adapter (M12) "4":
YU-90063/90890-01278
Spacer (crankshaft in-
staller) "5":
YM-91044/90890-04081
Bolt (oil strainer):
10 Nm (1.0 m•kg, 7.2
ft•lb)