engine YAMAHA WR 450F 2007 Owner's Guide

SPEC
2 - 20
EC220001
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fasten-
ers with standard I.S.O. pitch threads. Torque
specifications for special components or
assemblies are included in the applicable sec-
tions of this book. To avoid warpage, tighten
multi-fastener assemblies in a crisscross fash-
ion, in progressive stages, until full torque is
reached. Unless otherwise specified, torque
specifications call for clean, dry threads. Com-
ponents should be at room temperature.
A: Distance between flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
A
(Nut)B
(Bolt)TORQUE
SPECIFICATION
Nm mkg ftlb
10 mm
12 mm
14 mm
17 mm
19 mm
22 mm6 mm
8 mm
10 mm
12 mm
14 mm
16 mm6
15
30
55
85
1300.6
1.5
3.0
5.5
8.5
134.3
11
22
40
61
94
Unit Read Definition Measure
mm
cmmillimeter
centimeter10
-3 meter
10-2 meterLength
Length
kg kilogram 10
3 gram Weight
N Newton 1 kg
× m/sec
2 Force
Nm
m  kgNewton meter
Meter kilogramN
× m
m
× kgTorque
Torque
Pa Pascal N/m
2Pressure
N/mm Newton per millimeter N/mm Spring rate
L
cm
3 Liter
Cubic centimeter—
—Volume or capacity
Volume or capacity
r/min Revolution per minute
—Engine speed
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS

2 - 24
SPECCABLE ROUTING DIAGRAM
ÈInsert the end of the fuel tank breather hose into
the hole in the steering stem.
ÉFasten the throttle cable, hot starter cable and
rectifier/regulator lead onto the frame. Locate
the clamp end facing the lower side of the hot
starter cable and cut off the tie end.
ÊFasten the diode (at the marking), throttle cable
and hot starter cable onto the frame. Locate the
clamp end facing toward the lower right of the
frame and with the tie end facing downward.
ËFasten the wire harness, throttle position sensor
lead and clutch cable onto the frame. Pass the
clamp through the hole in the stay (air cut-off
valve). Locate the clamp end facing toward the
lower side of the frame and cut off the tie end.ÌFasten the throttle position sensor lead onto the
frame. Locate the clamp end facing toward the
lower side of the frame and cut off the tie end.
ÍPass the carburetor breather hoses, carburetor
overflow hose and catch tank breather hose
between the connecting rod and cross tube
(frame).
ÎPass the neutral switch lead on the inside of the
engine bracket.
ÏFasten the neutral switch lead and AC magneto
lead onto the frame. Locate the clamp end fac-
ing toward the outside of the frame and tie end
facing toward the rear of the frame.

2 - 28
SPECCABLE ROUTING DIAGRAM
1Clamp
2Positive battery lead
3Battery
4Negative battery lead
5Taillight coupler
6CDI unit coupler (6-pin)
7CDI unit coupler (3-pin)
8CDI unit coupler (6-pin)ÈFasten the wire harness to the upper engine
bracket (left side). Locate the clamp end facing
toward the upper side of the frame with the tie
end cut off on the inside of the frame.
ÉFasten the wire harness to the upper engine
bracket (left side). Locate the clamp end facing
toward the upper side of the frame with the tie
end cut off on the inside of the frame. Clamp the
wire harness at the marking.
ÊPass the starter motor lead through the hole in
the relay holder.
ËFit the cover securely.
ÌConnect the wire harness to the starter relay.

2 - 30
SPECCABLE ROUTING DIAGRAM
1Throttle cable
2Clamp
3Brake hose
4Clutch cable
5Hose guide
6Main switch coupler
7Wire harness
8Headlight coupler
9Hot starter cable
0Multi-function display bracket
AMain switch
BUpper bracket
CClutch switch coupler
DEngine stop switch coupler
EMulti-function display coupler
FStart switch coupler
GSpeed sensor coupler
HSpeed sensor lead

2 - 31
SPECCABLE ROUTING DIAGRAM
ÈFasten the start switch lead to the handlebar
with the plastic bands.
ÉFasten the engine stop switch lead and clutch
switch lead to the handlebar with the plastic
bands.
ÊPass the brake hose through the hose guides.
ËSecure the coupler by inserting it into the multi-
function display bracket.
ÌPass the throttle cables, clutch cable and hot
starter cable between the upper bracket and
multi-function display bracket.
ÍFasten the multi-function display leads to the
bracket. Cut off the tie end.
ÎSecure the coupler by pushing it into the hole in
the multi-function display bracket.
ÏSecure the wire harness clip by pushing it into
the hole in the multi-function display bracket on
the inside.ÐFasten the main switch lead (wire harness side)
to the multi-function display bracket. Locate the
clamp end facing toward the lower side of the
frame and cut off the tie end.
ÑPass the speed sensor lead through the guide
on the outside of the front fork.

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks
ENGINE OIL
Replace
VALVES
The engine must be cold.
Check the valve seats
and valve stems for wear. Check the valve clearances
Inspect
Replace
VALVE SPRINGS
Check the free length and
the tilt. Inspect
Replace
VALVE LIFTERS
Check for scratches and
wear. Inspect
Replace
CAMSHAFTS Inspect the camshaft sur-
face.
Inspect the decompres-
sion system Inspect
Replace
CAMSHAFT SPROCKETS
Check for wear on the
teeth and for damage. Inspect
Replace
PISTON
Inspect crack
Inspect carbon deposits
and eliminate them. Inspect
Clean
Replace
PISTON RING
Check ring end gap Inspect
Replace
PISTON PIN
Inspect
Replace
CYLINDER HEAD Inspect carbon deposits
and eliminate them.
Change gasket Inspect and clean
CYLINDER
Inspect and clean
Inspect score marks
Inspect wear
Replace
CLUTCH
Inspect housing, friction
plate, clutch plate and
spring Inspect and adjust
Replace
TRANSMISSION
Inspect
Replace bearing
SHIFT FORK, SHIFT CAM, GUIDE BAR
InspectInspect wear

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-21
Engine oilCheck that the oil level is correct. Check the crankcase and oil
line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9 ~ 10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-25 ~ 31
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-32 ~ 35
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-43 ~ 44
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-44 ~ 46
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-35 ~ 42
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.—
Muffler Check that the muffler is tightly mounted and has no cracks.—
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-32
Lubrication Check for smooth operation. Lubricate if necessary. P.3-47
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-26
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 20

3 - 5
INSP
ADJ
EC350000
ENGINE
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap
1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
1. Place the machine on a level place, and
hold it in an upright position.
2. Remove:
Radiator cap
3. Check:
Coolant level a
Coolant level low → Add coolant.
1Radiator
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
ENGINE/COOLANT LEVEL INSPECTION/
COOLANT REPLACEMENT

3 - 6
INSP
ADJ
COOLANT REPLACEMENT
CAUTION:
Take care so that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
1. Place a container under the engine.
2. Remove:
Seat
Left side cover
3. Remove the catch tank hose from the catch
tank and drain the tank of its coolant.
4. Remove:
Coolant drain bolt 1
5. Remove:
Radiator cap
Drain the coolant completely.
6. Clean:
Cooling system
Thoroughly flush the cooling system with
clean tap water.
7. Install:
Copper washer
Coolant drain bolt
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

3 - 7
INSP
ADJ
COOLANT REPLACEMENT
8. Fill:
Radiator
Engine
To specified level.
CAUTION:
Do not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
Do not use water containing impurities or
oil.
Recommended coolant:
High quality ethylene glycol
anti-freeze containing
anti-corrosion for
aluminum engine
Coolant
1 and water
(soft water)
2 mixing ratio:
50%/50%
Coolant capacity:
1.0 L (0.88 Imp qt, 1.06 US qt)
Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
When coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
When coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
When coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
9. Install:
Radiator cap
Start the engine and warm it up for a
several minutes.
10. Check:
Coolant level
Coolant level low → Add coolant.