2000 YAMAHA YZ426F ignition

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

1 - 6
GEN
INFO
SPECIAL TOOLS
EC140001
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the
correct special tool will help prevent damage caused by the use of improper tools or improvised
techniques. The shape and part number used for the special tool differ by country, so two types are
provided. Refer to the list provided to avoid errors when placing an order.
NOTE:
lFor U.S.A. and Canada, use part number starting with “YM-” or “YU-”.
lFor others, use part number starting with “90890-”.
Part number Tool name/How to use Illustration
YU-01135-A, 90890-01135
YM-01305, 90890-01305Crankcase separating tool
Crankcase separating bolt
These tools are used to split the crankcase as well as
remove the crankshaft from either case.YU-01135-A
YM-0130590890-01135
90890-01305
YU-01235, 90890-01235 Rotor holding tool
This tool is used when loosening or tightening the fly-
wheel magneto securing nut.YU-01235 90890-01235
YU-03097, 90890-01252
YU-01256Dial gauge and stand
Stand
These tools are used to set the ignition timing.YU-03097
YU-0125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YU-91044, 90890-04081
YU-90062, 90890-01277Crankcase installing tool
Pot
Bolt
Spacer
Adapter
These tools are used to install the crankshaft.YU-90050
YU-90062
YU-9104490890-01274
90890-01275
90890-01277
90890-04081
YU-01304, 90890-01304 Piston pin puller
This tool is used to remove the piston pin.YU-01304 90890-01304
YU-24460-1, 90890-01325
YU-33984, 90890-01352Radiator cap tester
Adapter
These tools are used for checking the cooling sys-
tem.YU-24460-01
YU-3398490890-01325
90890-01352
YM-01189, 90890-01189 Flywheel puller
This tool is used to remove the flywheel magneto.YM-01189 90890-01189

1 - 7
GEN
INFO
SPECIAL TOOLS
YM-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YM-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-03112, 90890-03112 Yamaha pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-03112 90890-03112
YU-8036-1
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-8036-1 90890-03113
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-04019, 90890-04019
YM-04108, 90890-04108Valve spring compressor
Attachment
This tool needed to remove and install the valve
assemblies.YM-04019
YM-0410890890-04019
90890-04108
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)
Exhaust (5.0 mm)
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

1 - 8
GEN
INFO
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)
Exhaust (5.0 mm)
This tool is needed to rebore the new valve guide.YM-4118
YM-409990890-04118
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-11001-05-01
90890-85505Quick gasket
â
YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.ACC-11001-05-01 90890-85505
Part number Tool name/How to use Illustration

SPEC

2 - 3
GENERAL SPECIFICATIONS
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/manufacturer F5JG/YAMAHA ----
Source coil 1 resistance (color) 720 ~ 1,080 W at 20 ˚C (68 ˚F)
(Green – Brown)----
Source coil 2 resistance (color) 44 ~ 66 W at 20 ˚C (68 ˚F)
(Black – Pink)----
Pickup coil resistance (color) 248 ~ 372 W at 20 ˚C (68 ˚F)
(White – Red)----
CDI unit-model/manufacturer 5JG/YAMAHA ----
Ignition coil:
Model/manufacturer JF2/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary winding resistance 0.20 ~ 0.30 W at 20 ˚C (68 ˚F) ----
Secondary winding resistance 9.5 ~ 14.3 kW 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 M10 ´ 1.25 1 48 4.8 35
Ignition coil M6 ´ 1.0 2 7 0.7 5.1

2 - 23
SPEC
ôFit the brake hose into the guide on
the protector.
çFasten the ignition coil lead (in the
sub wire harness) on the upper
inside of the frame and cut off the tie
end.
óPass the ignition coil lead (in the sub
wire harness) under the cushion
bracket (frame).
Fasten the ignition coil lead (in the
sub wire harness) to the frame with
a plastic locking tie.
Pass the carburetor breather hoses
and overflow hose so that all there
hoses do not contact the rear
shock absorber.

CABLE ROUTING DIAGRAM

2 - 24
SPECCABLE ROUTING DIAGRAM
1Clamp
2Ignition coil
3High tension cord
4CDI unit
5CDI unit band
6Throttle cable (pull)
7Throttle cable (return)
8Radiator (left)
9Radiator breather hose
0Radiator (right)
ACDI unit stay (frame)Fasten the ignition coil lead to the
frame with a plastic band.
õFasten the ignition coil and
ground lead to the frame with the
bolt.
‚Pass the ignition coil lead (in the
sub wire harness) so that it does
not contact the carburetor and
rear shock absorber and connect
it with the lead from the ignition
coil on the inside of the frame.
ëPass the throttle cables over the
high tension cord.
äPass the throttle cables along the
outer side of the CDI unit leads.
ìFasten the CDI unit leads to the
frame with a plastic locking tie.
íPass the throttle cables between
the top radiator mounting boss
and middle radiator mounting
boss.îPass the CDI unit leads over the
top radiator mounting boss.
éCross the pull and return throttle
cables before the radiator.
ïPass the throttle cables through
cable guide on the frame.
ðPass the radiator breather hose
between the frame and the radia-
tor without pinching it.
ñPass the radiator breather hose
behind the decompression cable.
÷Insert the CDI unit band over the
CDI unit stay (frame) as far as
possible.