brake YAMAHA WR 450F 2007 User Guide

2 - 23
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Clamp
3Diode
4Hot starter cable
5Throttle position sensor lead
6Wire harness
7Hump (frame)
8Negative battery lead
9Starter motor lead
0Neutral switch lead
AAC magneto lead
BBrake hose
CRectifier/regulator leadDCarburetor breather hose
ECarburetor overflow hose
FCatch tank breather hose

2 - 27
SPECCABLE ROUTING DIAGRAM
1Brake master cylinder
2Brake hose holder
3Brake hoseÈInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the brake caliper.
ÉPass the brake hose into the brake hose hold-
ers.
ÊIf the brake hose contacts the spring (rear shock
absorber), correct its twist.
ËInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the brake master cylinder.

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 - 2
INSP
ADJ
MAINTENANCE INTERVALS
ROTOR NUT
Retighten
MUFFLER
Inspect and retighten
Clean
Replace * Whichever comes first
*SPARK ARRESTER
(Every six
months)
Clean
CRANK
Inspect and clean
CARBURETOR
Inspect, adjust and clean
AIR INDUCTION SYSTEM
Inspect and clean
SPARK PLUG
Inspect and clean
Replace
DRIVE CHAIN
Use chain lube
Chain slack: 48 ~ 58 mm
(1.9 ~ 2.3 in) Lubricate, slack, alignment
Replace
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant Every two years
Inspect hoses
OUTSIDE NUTS AND BOLTS Refer to “STARTING
AND BREAK-IN” section
in the CHAPTER 1. Retighten
AIR FILTER
Use foam air-filter oil or
equivalent oil Clean and lubricate
Replace
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 yearItemAfter
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.1-21
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 - 25
INSP
ADJ
CHASSIS/BRAKE SYSTEM AIR BLEEDING
EC360000
CHASSIS
EC361012
BRAKE SYSTEM AIR BLEEDING
WARNING
Bleed the brake system if:
The system has been disassembled.
A brake hose has been loosened or
removed.
The brake fluid is very low.
The brake operation is faulty.
A dangerous loss of braking performance
may occur if the brake system is not prop-
erly bled.
1. Remove:
Master cylinder cap
Diaphragm
Reservoir float (front brake)
Protector (rear brake)
2. Bleed:
Brake fluid
ÈFront
ÉRear
Air bleeding steps:
a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to
spill any fluid or allow the reservoir to
overflow.
c. Connect the clear plastic tube 2 tightly to
the caliper bleed screw 1.
d. Place the other end of the tube into a con-
tainer.
e. Slowly apply the brake lever or pedal sev-
eral times.
f. Pull the lever in or push down on the
pedal. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the
lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever or
pedal limit has been reached; then
release the lever or pedal.
T R..
Bleed screw:
6 Nm (0.6 m  kg, 4.3 ft  lb)
i. Repeat steps (e) to (h) until of the air bub-
bles have been removed from the sys-
tem.
È
É

3 - 26
INSP
ADJ
FRONT BRAKE ADJUSTMENT
3. Install:
Protector (rear brake)
Reservoir float (front brake)
Diaphragm
Master cylinder cap
NOTE:
If bleeding is difficult, it may be necessary to
let the brake fluid system stabilize for a few
hours. Repeat the bleeding procedure when
the tiny bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on the
reservoir.
WARNING
Check the operation of the brake after
bleeding the brake system.
EC362040
FRONT BRAKE ADJUSTMENT
1. Check:
Brake lever position a
Brake lever position
a:
Standard position Extent of adjustment
95 mm (3.74 in)76 ~ 97 mm
(2.99 ~ 3.82 in)
2. Remove:
Lever cover
3. Adjust:
Brake lever position
4. Install:
Lever cover Brake lever position adjustment steps:
Loosen the locknut 1.
Turn the adjusting bolt 2 until the lever
position a is within specified position.
Tighten the locknut.
T R..
Locknut:
5 Nm (0.5 m  kg, 3.6 ft  lb)
CAUTION:
Be sure to tighten the locknut, as it will
cause poor brake performance.

3 - 27
INSP
ADJREAR BRAKE ADJUSTMENT/
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
EC364002
REAR BRAKE ADJUSTMENT
1. Check:
Brake pedal height a
Out of specification → Adjust.
Brake pedal height
a:
10 mm (0.39 in)
2. Adjust:
Brake pedal height
Pedal height adjustment steps:
Loosen the locknut 1.
Turn the adjusting nut 2 until the pedal
height a is within specified height.
Tighten the locknut.
WARNING
Adjust the pedal height between the
maximum
È and the minimum
É as
shown. (In this adjustment, the bolt
3
end
b should protrude out of the
threaded portion
4 but not be less than
2 mm (0.08 in)
c away from the brake
pedal
5).
After the pedal height adjustment, make
sure that the rear brake does not drag.
È
É
EC365080
FRONT BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
Brake pad thickness a
Out of specification → Replace as a set.
2. Replace:
Brake pad
Brake pad thickness
a:
Standard
4.4 mm (0.17 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
Remove the pad pin plug 1.

3 - 28
INSP
ADJ
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
Loosen the pad pin 2.
Remove the caliper 3 from the front fork.
Remove the pad pin and brake pads 4.
Connect the transparent hose 5 to the
bleed screw 6 and place the suitable con-
tainer under its end.
Loosen the bleed screw and push the cali-
per piston in.
CAUTION:
Do not reuse the drained brake fluid.
Tighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m  kg, 4.3 ft  lb)
Install the brake pads 7 and pad pin.
NOTE:
Install the brake pads with their projections
a into the caliper recesses b.
Temporarily tighten the pad pin at this
point.
Install the caliper 8 and tighten the pad
pin 9.
T R..
Bolt (caliper):
23 Nm (2.3 m  kg, 17 ft  lb)
Pad pin:
18 Nm (1.8 m  kg, 13 ft  lb)