2003 YAMAHA WR 450F brake

SPEC
2 - 15
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench, then loosen the ring nut one turn.
2. Retighten the ring nut 7 Nm (0.7 m • kg, 5.1 ft • lb). Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Handle crown and outer tube M8 × 1.25 4 23 2.3 17
Under bracket and outer tube M8 × 1.25 4 20 2.0 14
Handle crown and steering shaft M24 × 1.0 1 145 14.5 105
Handlebar holder (upper) M8 × 1.25 4 28 2.8 20
Steering ring nut M28 × 1.0 1 Refer to NOTE.
Front fork and cap bolt M48 × 1.0 2 30 3.0 22
Front fork and base valve M30 × 1.0 2 55 5.5 40
Cap bolt and damper rod (front fork) M12 × 1.25 2 29 2.9 21
Bleed screw (front fork) and cap bolt M5 × 0.8 2 1 0.1 0.7
Front fork and protector M6 × 1.0 6 10 1.0 7.2
Front fork and brake hose holder M6 × 1.0 2 10 1.0 7.2
Front fork and hose cover M8 × 1.25 1 16 1.6 11
Front fork and hose cover M6 × 1.0 1 7 0.7 5.1
Throttle cable cap M5 × 0.8 2 4 0.4 2.9
Clutch lever holder mounting M5 × 0.8 2 4 0.4 2.9
Hot starter lever holder mounting M5 × 0.8 2 4 0.4 2.9
Hot starter lever mounting M5 × 0.8 1 2 0.2 1.4
Lights switch M4 × 0.7 2 2 0.2 1.4
Front brake master cylinder and bracket M6 × 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 6 0.6 4.3
Brake lever mounting (nut) M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
Hose guide (front brake hose) M5 × 0.8 2 4 0.4 2.9
Front brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22
Front brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
Front brake caliper and front fork M8 × 1.25 2 23 2.3 17
Brake caliper (front and rear) and pad pin plug M10 × 1.0 2 3 0.3 2.2
Brake caliper (front and rear) and pad pin M10 × 1.0 2 18 1.8 13
Brake caliper (front and rear) and bleed screw M8 × 1.25 2 6 0.6 4.3
Front wheel axle and nut M16 × 1.5 1 105 10.5 75
Front wheel axle holder M8 × 1.25 4 23 2.3 17
Front brake disc and wheel hub M6 × 1.0 6 12 1.2 8.7
Rear brake disc and wheel hub M6 × 1.0 6 14 1.4 10
Brake pedal mounting M8 × 1.25 1 26 2.6 19
Rear brake master cylinder and frame M6 × 1.0 2 11 1.1 8.0
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Rear brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
Rear brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22

SPEC
2 - 16
MAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Rear wheel axle and nut M20 × 1.5 1 125 12.5 90
Driven sprocket and wheel hub M8 × 1.25 6 50 5.0 36
Nipple (spoke)–72 3 0.3 2.2
Disc cover and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Chain puller adjust bolt and locknut M8 × 1.25 2 16 1.6 11
Engine mounting:
Engine upper bracket and frame M10 × 1.25 2 55 5.5 40
Engine lower bracket and frame M8 × 1.25 4 34 3.4 24
Engine and frame (front) M10 × 1.25 1 69 6.9 50
Engine and frame (upper) M10 × 1.25 1 55 5.5 40
Engine and frame (lower) M10 × 1.25 1 69 6.9 50
Engine guard (left and right) M8 × 1.25 2 23 2.3 17
Engine skid plate mounting M6 × 1.0 6 10 1.0 7.2
Regulator bracket mounting M6 × 1.0 2 7 0.7 5.1
Regulator mounting M6 × 1.0 2 7 0.7 5.1
Pivot shaft and nut M16 × 1.5 1 85 8.5 61
Relay arm and swingarm M14 × 1.5 1 80 8.0 58
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame and frame (upper) M8 × 1.25 1 32 3.2 23
Rear frame and frame (lower) M8 × 1.25 2 29 2.9 21
Swingarm and brake hose holder M5 × 0.8 4 1 0.1 0.7
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Drive chain tensioner mounting (upper) M8 × 1.25 1 19 1.9 13
Drive chain tensioner mounting (lower) M8 × 1.25 1 20 2.0 14
Chain support and swingarm M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank mounting M6 × 1.0 2 10 1.0 7.2
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M6 × 1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M6 × 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 × 1.0 4 7 0.7 5.1
Seat mounting M8 × 1.25 2 23 2.3 17
Side cover mounting M6 × 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 6 4 0.4 2.9
Air scoop and radiator panel (lower) M6 × 1.0 2 4 0.4 2.9
Front fender mounting M6 × 1.0 4 7 0.7 5.1
Rear fender mounting (front) M6 × 1.0 2 7 0.7 5.1
Rear fender mounting (rear) M6 × 1.0 2 10 1.0 7.2
Trip meter mounting M6 × 1.0 2 7 0.7 5.1

2 - 23
SPEC

CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Fuel tank breather hose
2
Clamp
3
Diode
4
Wire harness
5
Hot starter cable
6
Negative battery lead
7
Starter motor lead
8
TPS (throttle position sen-
sor) lead
9
Neutral switch lead
0
Oil hose
A
Hose holder
B
Radiator hose 4
C
Cylinder head breather hose
D
AC magneto lead
E
Radiator hose 1
F
Oil tank breather hose
G
Lights switch lead
H
Brake hose
I
Hose guide
J
Carburetor breather hose
K
Overflow hose
LCoolant reservoir tank breather
hose
ÅInsert the fuel tank breather
hose into the hole in the steering
shaft cap.
ıFasten the diode of the wire har-
ness and rectifier/regulator lead
(at its protecting tube) to the
frame at the white tape for the
diode with a plastic locking tie
and cut off the tie end.ÇFasten the wire harness, recti-
fier/regulator lead, coolant res-
ervoir hose and hot starter cable
to the frame with a plastic lock-
ing tie and cut off the tie end.
ÎFasten the wire harness, recti-
fier/regulator lead and coolant
reservoir hose to the frame with
a plastic locking tie and cut off
the tie end.
‰Fasten the wire harness to the
frame at its white tape with a
plastic locking tie and cut off the
tie end.

2 - 24
SPECCABLE ROUTING DIAGRAM
ÏFasten the wire harness, TPS
lead (in the wire harness),
starter motor lead and negative
battery lead to the frame with a
plastic locking tie and cut off
the tie end.
ÌMake sure that the TPS cou-
pler does not go out the chas-
sis.
ÓFasten the TPS lead to the
frame with a plastic band.
ÈFasten the neutral switch lead
and oil hose together with the
plastic locking ties and cut off
the tie ends.
ÔPass the cylinder head
breather hose through the hose
holder.Fasten the neutral switch lead
to the frame with a plastic band
ends outward.
ÒFasten the neutral switch lead
and AC magneto lead to the
frame with a plastic band.
˜Pass the cylinder head
breather hose on the outside of
the radiator hose 1 and on the
inside of the radiator pipe (radi-
ator hose 4).
ˆPass the oil tank breather hose
on the outside of the AC mag-
neto lead, neutral switch lead,
lights switch lead, wire harness
and cylinder head breather
hose.ØPass the wire harness on the
outside of the neutral switch
lead and AC magneto lead.
∏Fit the brake hose into the
guides on the protector.
ŒPass the wire harness through
the cable guide.
ÂFasten the AC magneto lead,
neutral switch lead and lights
switch lead to the cable guide
at their protecting tube with a
plastic locking tie and cut off
the tie end.
ÍPass the carburetor breather
hoses, overflow hose and cool-
ant reservoir tank breather
hose so that the hoses do not
contact the rear shock
absorber.

2 - 26
SPECCABLE ROUTING DIAGRAM
1Master cylinder
2Brake hose holder
3Brake hoseÅInstall the brake hose so that its
pipe portion directs as shown and
lightly touches the projection on
the caliper.
ıPass the brake hose into the
brake hose holders.
ÇIf the brake hose contacts the
spring (rear shock absorber), cor-
rect its twist.
ÎInstall the brake hose so that its
pipe portion directs as shown and
lightly touches the projection on
the master cylinder.

2 - 28
SPECCABLE ROUTING DIAGRAM
1Throttle cable
2Brake hose
3Clamp
4Lights switch lead
5Hot starter cable
6Clutch cable
7Hose guide
8Clutch switch lead
9“ENGINE STOP” button
lead
0Trip meter cable
AMain switch lead
BTrip meter
CMain switch
DLights switch
EStart switch leadÅFasten the start switch lead and
lights switch lead to the handlebar
with a plastic band.
ıFasten the “ENGINE STOP” but-
ton lead and clutch switch lead to
the handlebar with the plastic
bands.
ÇPass the brake hose through the
hose guide.
ÎPass the start switch lead in front
of the main switch lead.
‰Fasten the start switch lead to the
handlebar with a plastic band.
ÏPass the hot starter cable and
lights switch lead between the
handle crown and coupler
bracket.ÌPass the throttle cables and clutch
cable between the handle crown
and trip meter.

3 - 2
INSP
ADJ

MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
●
Inspect wear
ROTOR NUT
Retighten
●

●

MUFFLER
Inspect and retighten
Clean
Replace
●

●

●

●
* Whichever comes first
*SPARK ARRESTER
Clean
(Every
six
months)
●
CRANK
Inspect and clean
●

●

CARBURETOR
Inspect, adjust and clean
●

●

SPARK PLUG
Inspect and clean
Replace
●

●

●

DRIVE CHAIN
Lubricate, slack, alignment
Replace
●

●

●
Use chain lube
Chain slack: 40 ~ 50 mm
(1.57 ~ 1.97 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
●

●

●

●

●
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
●

●
Refer to “STARTING
AND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
●

●

●
Use foam air-filter oil or
equivalent oil
OIL FILTER
Replace
●

●

OIL STRAINER (frame)
Clean
●

FRAME
Clean and inspect
●

●

FUEL TANK, COCK
Clean and inspect
●

●

BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid
●

●

●

●

●

●

●

●

●

●

●

●
Every one year ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks


3

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.1-14
Engine oilCheck that the oil level is correct. Check the crankcase and
frame 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.3-10
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.3-26 ~ 32
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-33 ~ 36
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-44 ~ 45
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-45 ~ 46
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-36 ~ 43
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.3-33
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.1-19
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 ~ 21