ignition YAMAHA YZ450F 2003 Owners Manual

CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM
...........................6-1
MAP-CONTROLLED CDI UNIT
.................6-2
IGNITION SYSTEM
....................................6-3
TPS (THROTTLE POSITION SENSOR)
SYSTEM
.....................................................6-7
CHAPTER 7
TUNING
ENGINE
......................................................7-1
CHASSIS
.................................................7-10

GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-1423, 90890-01423 Damper rod holder
Use this tool to remove and install the damper rod.YM-1423 90890-01423
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YU-3112-C, 90890-03112 Yamaha pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YU-8036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-8036-B 90890-03113
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-4019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-4019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-4116, 90890-04116
YM-4097, 90890-04097Valve guide remover
Intake 4.5 mm (0.18 in)
Exhaust 5.0 mm (0.20 in)
This tool is needed to remove and install the valve
guide.YM-4116
YM-409790890-04116
90890-04097
Part number Tool name/How to use Illustration

GEN
INFO
1 - 9
SPECIAL TOOLS
YM-4117, 90890-04117
YM-4098, 90890-04098Valve guide installer
Intake
Exhaust
This tool is needed to install the valve guide.YM-4117
YM-409890890-04117
90890-04098
YM-4118, 90890-04118
YM-4099, 90890-04099Valve guide reamer
Intake 4.5 mm (0.18 in)
Exhaust 5.0 mm (0.20 in)
This tool is needed to rebore the new valve guide.YM-4118
YM-4099 90890-04118
90890-04099
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.YM-34487 90890-06754
ACC-QUICK-GS-KT
90890-85505Quick gasket

YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.ACC-QUICK-GS-KT 90890-85505
Part number Tool name/How to use Illustration

SPEC

2 - 3
GENERAL SPECIFICATIONS
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 300 mm (11.8 in)
Rear wheel travel 315 mm (12.4 in)
Electrical:
Ignition system CDI magneto

SPEC
2 - 17
MAINTENANCE SPECIFICATIONS
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Advancer type Electrical ----
C.D.I.:
Magneto-model (stator)/manufacturer 5SF-00/YAMAHA ----
Source coil 1 resistance (color) 720 ~ 1,080 Ω at 20 ˚C (68 ˚F)
(Green – Brown)----
Source coil 2 resistance (color) 44 ~ 66 Ω at 20 ˚C (68 ˚F)
(Black – Pink)----
Pickup coil resistance (color) 248 ~ 372 Ω at 20 ˚C (68 ˚F)
(White – Red)----
CDI unit-model/manufacturer 5TA-00/YAMAHA ----
Ignition coil:
Model/manufacturer 5TA-00/DENSO ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.08 ~ 0.10 Ω at 20 ˚C (68 ˚F) ----
Secondary winding resistance 4.6 ~ 6.8 kΩ at 20 ˚C (68 ˚F) ----
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Stator M6 × 1.0 3 10 1.0 7.2
Rotor M12 × 1.25 1 56 5.6 40
Neutral switch M5 × 0.8 2 4 0.4 2.9

2 - 21
SPEC

CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Fuel tank breather hose
2
Hot starter cable
3
Radiator hose 4
4
Cylinder head breather hose
5
Radiator hose 1
6
Oil tank breather hose
7
Hose guide
8
Brake hose
9
“ENGINE STOP” button lead
0
Clamp
A
Sub wire harness
B
TPS (throttle position sen-
sor) lead
C
Neutral switch lead
D
Oil hose
E
Radiator breather hose
F
CDI magneto lead
G
Carburetor breather hose
H
Overflow hose
Å
Pass the fuel tank breather hose
between the handlebar and ten-
sion bar, then insert its end into
the hole of the number plate.
ı
Pass the hot starter cable
between the cylinder head
breather hose, oil tank breather
hose and ignition coil, then on
the outside of the left engine
bracket.
Ç
Pass the cylinder head breather
hose on the outside of the radia-
tor hose 1 and on the inside of the
radiator pipe (radiator hose 4).
Î
Fit the brake hose into the
guides on the protector.
‰
Fasten the “ENGINE STOP”
button lead and sub wire har-
ness to the frame with a plastic
locking tie and cut off the tie
end.
ÏFasten the sub wire harness
and hot starter cable to the
frame at the white tape for the
sub wire harness with a plastic
locking tie and cut off the tie
end.
ÌFasten the sub wire harness to
the frame with a plastic locking
tie and cut off the tie end.
C
9
0
A
0
0
0
0
0
B
C
D
0 0 E 0 F 0
1
2 8
7
6
5
4
3GHG9A
D
E
C
B
A
A
C
BB
Ç ÎÅ
ıØ
˜ ˆ
Ò
Ô ÈÌ Ó Ì Ï ‰ ‰
∏
*
*

2 - 23
SPECCABLE ROUTING DIAGRAM
1Cable holder
2CDI unit
3Hot starter cable
4Clutch cable
5Throttle cable (return)
6Throttle cable (pull)
7Ignition coil
8Radiator breather hose
9Radiator hose 4
0Cylinder head breather
hose
ACDI unit bracket
BCDI unit bandÅFasten the grommet of the clutch
cable with the cable holder.
ıPass the hot starter cable, clutch
cable and throttle cables through
the cable guides.
ÇPass the hot starter cable over the
top radiator mounting boss.
ÎPass the hot starter cable, clutch
cable and throttle cables between
the radiator and frame, then over
the middle radiator mounting
boss.
‰Pass the clutch cable and throttle
cables on the outside of the igni-
tion coil.
ÏPass the radiator breather hose at
the rear of the radiator, on the left
of the chassis, and then between
the frame and radiator hose 4.ÌInsert the CDI unit band over the
CDI unit bracket as far as possi-
ble.
ÓFirst install the CDI unit and CDI
unit band to the CDI unit bracket,
then the CDI unit bracket to the
frame.
0
8
92
BA
3
4
5
6
712 ÏÓÌ
ı
Ç
Î
‰ ÅB
A
A
B

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.1-17
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-13 ~ 17
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
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
Brakes Check the play of front brake and effect of front and rear brake. P.3-24 ~ 30
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-31 ~ 33
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-41 ~ 42
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-42 ~ 43
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-33 ~ 40
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.3-31
Lubrication Check for smooth operation. Lubricate if necessary. P.3-44
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-22
Lead connectorsCheck that the CDI 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

3 - 46
INSP
ADJ
IGNITION TIMING CHECK
IGNITION TIMING CHECK
1. Remove:
Timing plug 1
2. Attach:
Timing light
Inductive tachometer
To the spark plug lead.
3. Check:
Ignition timing
Timing light:
YM-33277-A/90890-03141
Inductive tachometer:
YU-8036-B
Engine tachometer:
90890-03113
Checking steps:
Start the engine and let it warm up. Let the
engine run at the specified speed.
Engine speed:
1,900 ~ 2,100 r/min
Visually check the stationary pointer a is
within the firing range b on the rotor.
Incorrect firing range → Check rotor and
pickup assembly.
4. Install:
Timing plug

4 - 80
ENGENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is no
danger of it falling over.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable and guide Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “CDI MAGNETO” section.
Cylinder head breather hose and
oil tank breather hoseRefer to “CAMSHAFTS” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Ignition coil
Disconnect the CDI magneto lead.