2005 YAMAHA WR 450F carburetor

2 - 24
SPECCABLE ROUTING DIAGRAM
ÍFasten 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.
ÎMake sure that the TPS coupler
does not go out the chassis.
ÏFasten the TPS lead to the
frame with a plastic band.
ÐFasten the neutral switch lead
and oil hose together with the
plastic locking ties and cut off
the tie ends.
ÑFasten 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 ends
outward.
ÓPass the oil tank breather hose
on the outside of the AC mag-
neto lead, neutral switch lead,
wire harness, rectifier/regulator
lead and cylinder head breather
hose.
ÔPass the wire harness on the
outside of the neutral switch
lead and AC magneto lead.
ÕPass the wire harness through
the cable guide.
ÖFasten the rectifier/regulator
lead to the cable guide with a
plastic locking tie and cut off the
tie end.×Fasten the AC magneto lead
and neutral switch lead to the
cable guide at their protecting
tube with a plastic locking tie.
ØPass the carburetor breather
hoses, overflow hose and cool-
ant reservoir tank breather
hose so that the hoses do not
contact the rear shock
absorber.
ÙUsing a plastic locking tie, fas-
ten the neutral switch lead to
the frame together with the CDI
unit lead on the right of the
frame and then cut off the tie
end.
2
Ù
B
BA
B-B
A
A
0Ò2
Ñ2 B ÓC Ô D
EFÕÖ2
×2F
1
È
2
É
3
2
Ê
452
Ë
2
Ì2
Í
6
7
Î
2
Ï
8
9
0
A 2
ÐØ GG
HI

2 - 25
SPECCABLE ROUTING DIAGRAM
1Hot starter cable
2Clutch cable
3Throttle cable (return)
4Throttle cable (pull)
5Ignition coil
6Negative battery lead
7Starter motor lead
8Coolant reservoir tank breather
hose
9Cable holder
0Coolant reservoir hose
AClamp
BCDI unit lead
CCDI unit
DCDI unit band
ECDI unit stay (frame)
FCable bracketÈPass the throttle cables, clutch
cable and hot starter cable
through the cable guides.
ÉPass the throttle cables, clutch
cable and hot starter cable
between the radiator and frame,
then over the middle radiator
mounting boss.
ÊPass the throttle cables and
clutch cable on the outside of
the ignition coil.
ËPass the carburetor breather
hose (throttle cable cover)
through the hose holder.
ÌFasten the coolant reservoir
tank breather hose and carbure-
tor breather hoses together with
a plastic locking tie.ÍFasten the grommet of the clutch
cable with the cable holder.
ÎFasten the CDI unit lead to the
frame with a plastic locking tie
ends at the lower of the frame
and cut off the tie end.
ÏInsert the CDI unit band over the
CDI unit stay (frame) as far as
possible.
ÐFasten the starter motor lead
and negative battery lead to the
cable bracket in its slot with a
plastic locking tie and cut off the
tie end.
A
A
D
ÏE A
Ð
B
B
C
F
Í90
ÎABCD
1
2
43
È
É
Ê
5
6 7 8 Ë Ì

2 - 27
SPECCABLE ROUTING DIAGRAM
1Starter motor lead
2Negative battery lead
3Wire harness
4Clamp
5Taillight lead
6Coolant reservoir tank breather
hose
7Coolant reservoir hose
8Positive battery lead
9Starting circuit cut-off relay
0BatteryÈPosition the starter motor lead,
negative battery lead and wire
harness in the tank damper slit.
ÉFasten the wire harness to the
frame with a plastic locking tie
and cut off the tie end.
ÊFasten the coolant reservoir
tank breather hose and coolant
reservoir hose to the frame with
a plastic locking tie.
ËDo not allow the taillight lead to
slacken.
ÌPass the starter motor lead and
negative battery lead over the
carburetor.
ÍFasten the coolant reservoir
tank breather hose and coolant
reservoir hose to the frame with
a plastic band.ÎPass the coolant reservoir hose
on the outside of the coolant
reservoir tank breather hose.
7Ì4
Í
5
Ë
4
Ê
7
6
È3
2
1
4
É
4
Í4
Í
Î 0
968
213
Zero ~ 10 mm
(Zero ~ 0.39 in)

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 - 19
INSP
ADJ
VALVE CLEARANCE ADJUSTMENT
VALVE CLEARANCE ADJUSTMENT
NOTE:
The valve clearance should be adjusted
when the engine is cool to the touch.
The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
Seat
Fuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
2. Remove:
Carburetor
Refer to “CARBURETOR” section in the
CHAPTER 4.
Spark plug
Engine stay (upper)
Cylinder head cover
Refer to “CAMSHAFTS” section in the
CHAPTER 4.
3. Remove:
Timing plug 1
Straight plug 2
O-ring
1
2
4. Check:
Valve clearance
Out of specification → Adjust.
Valve clearance (cold):
Intake valve:
0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)
Exhaust valve:
0.20 ~ 0.25 mm
(0.0079 ~ 0.0098 in)
Checking steps:
Turn the crankshaft counterclockwise with
a wrench.
Align the T.D.C. mark a on the rotor with
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.
b
a

3 - 48
INSP
ADJ
ELECTRICAL/SPARK PLUG INSPECTION
EC370000
ELECTRICAL
EC371001
SPARK PLUG INSPECTION
1. Remove:
Spark plug
2. Inspect:
Electrode 1
Wear/damage → Replace.
Insulator color 2
Normal condition is a medium to light tan
color.
Distinctly different color → Check the
engine condition.
NOTE:
When the engine runs for many hours at low
speeds, the spark plug insulator will become
sooty, even if the engine and carburetor are in
good operating condition.
3. Measure:
Plug gap a
Use a wire gauge or thickness gauge.
Out of specification → Regap.
Spark plug gap:
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
4. Clean the plug with a spark plug cleaner if
necessary.
5. Tighten:
Spark plug
NOTE:
Before installing a spark plug, clean the gas-
ket surface and plug surface.
Finger-tighten a the spark plug before torqu-
ing to specification b.
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)

4 - 8
ENGCARBURETOR
CARBURETOR
7 4
108 1
9
T R..2 Nm (0.2 m •
kg, 1.4 ft • Ib)
2
3
75
5
T R..4 Nm (0.4 m •
kg, 2.9 ft • Ib)
T R..3 Nm (0.3 m • kg, 2.2 ft • Ib)
6
T R..3 Nm (0.3 m • kg, 2.2 ft • Ib)
1
T R..4 Nm (0.4 m •
kg, 2.9 ft • Ib)
T R..11 Nm (1.1 m •
kg, 8.0 ft • Ib)
Extent of removal:
1 Carburetor removal
Extent of removal Order Part name Q’ty Remarks
CARBURETOR REMOVAL
Preparation for removal Fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Cylinder head breather hose Refer to “CAMSHAFTS” section.
1Clamp 1
2Band 1
3 TPS coupler 1
4 Throttle cable cover 1
5 Throttle cable 2
6 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
7 Clamp (carburetor joint) 2 Loosen the screws (carburetor joint).
8 Hot starter plunger 1
9 Carburetor 1
10 Carburetor joint 1
1

4 - 9
ENGCARBURETOR
CARBURETOR DISASSEMBLY
Extent of removal:
1 Carburetor disassembly
Extent of removal Order Part name Q’ty Remarks
CARBURETOR DISASSEMBLY
1 Breather hose 4
2 Valve lever housing cover 1
3 Screw (throttle shaft) 1
4 Throttle valve 1
5 Needle holder 1
6 Jet needle 1
7 Cover 1
8 Spring 1
9 Diaphragm (accelerator pump) 1
0 Air cut valve cover 1
A Spring (air cut valve) 1
B Diaphragm (air cut valve) 1
C Float chamber 1
D Leak jet 1
E Float pin 1
F Float 1
1