Page 24 of 762
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT BRAKE AND REAR BRAKE
..... 5-11
FRONT FORK
......................................... 5-28
HANDLEBAR
.......................................... 5-41
STEERING
.............................................. 5-46
SWINGARM
............................................ 5-52
REAR SHOCK ABSORBER
................... 5-59
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
LIGHTING SYSTEM
................................ 6-11
CHAPTER 7
TUNING
ENGINE
..................................................... 7-1
CHASSIS
................................................. 7-11
Page 39 of 762

1 - 8
GEN
INFO
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 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YU-08036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-08036-B 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 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-04019 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)
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
Page 40 of 762
1 - 9
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-QUICK-GS-KT
90890-85505Quick gasket
â
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
Page 76 of 762
2 - 3
SPEC
GENERAL SPECIFICATIONS (WR426F)
Tire:
Type With tube
Size (front) 80/100-21 51M (USA, CDN, ZA)
90/90-21 54R (EUROPE, AUS, NZ)
Size (rear) 110/100-18 64M (USA, CDN, ZA)
130/90-18 69R (EUROPE, AUS, NZ)
Tire pressure (front and rear) 100 kPa (1.0 kg/cm
2
, 15 psi)
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
Page 90 of 762
2 - 17
SPECMAINTENANCE SPECIFICATIONS (WR426F)
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI:
Magneto-model/manufacturer F5NG 00/YAMAHA ----
Source coil 1 resistance (color) 640 ~ 960 W at 20 ˚C (68 ˚F)
(Green – Brown)----
Source coil 2 resistance (color) 464 ~ 696 W at 20 ˚C (68 ˚F)
(Green – Pink)----
Lighting coil resistance (color) 0.16 ~ 0.24 W at 20 ˚C (68 ˚F)
(Black – Yellow)
Pickup coil resistance (color) 248 ~ 372 W at 20 ˚C (68 ˚F)
(White – Red)----
CDI unit-model/manufacturer 5NG-00/YAMAHA
(For USA)
5NG-10/YAMAHA
(Except for USA)----
Ignition coil:
Model/manufacturer 5BE-00/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
Page 93 of 762
2 - 20
SPECGENERAL SPECIFICATIONS (WR400F)
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
Page 107 of 762
2 - 34
SPECMAINTENANCE SPECIFICATIONS (WR400F)
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI:
Magneto-model/manufacturer F5BF 00/YAMAHA ----
Source coil 1 resistance (color) 640 ~ 960 W at 20 ˚C (68 ˚F)
(Green – Brown)----
Source coil 2 resistance (color) 464 ~ 696 W at 20 ˚C (68 ˚F)
(Green – Pink)----
Lighting coil resistance (color) 0.16 ~ 0.24 W at 20 ˚C (68 ˚F)
(Black – Yellow)
Pickup coil resistance (color) 248 ~ 372 W at 20 ˚C (68 ˚F)
(White – Red)----
CDI unit-model/manufacturer 5GS-60/YAMAHA ----
Ignition coil:
Model/manufacturer 5BE-00/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
Page 220 of 762

2 - 39
SPEC
CABLE ROUTING DIAGRAM
é
Fasten the TPS lead (in the
sub wire harness) under the
frame so that it does not con-
tact the carburetor.
ï
Fasten the TPS lead under the
coupler to the frame with a
plastic locking tie.
ð
Pass the carburetor breather
hose and overflow hose
between the connecting rod
and cross tube (frame).
ñ
Fasten the neutral switch lead
and oil hose together with a
plastic locking tie.
÷
Fasten the neutral switch lead
to the frame with a plastic
band.
öFasten the cylinder head
breather hose with the hose
holder.¯Fasten the neutral switch lead
and CDI magneto lead
together with a plastic band.
¸Pass the clutch cable through
the cable guide.
ÎPass the cylinder head
breather hose along the inner
side of the radiator pipe.
åPass the clutch cable between
the frame and radiator and
over the lower boss on the
radiator.
êPass the neutral switch lead
and CDI magneto lead over
the middle radiator mounting
boss. Then, pass the decom-
pression cable under the mid-
dle radiator mounting boss
and along the left side of the
neutral switch lead and CDI
magneto lead.æPass the clutch cable through
the cable guide.
èFit the brake hose into the
guide on the protector.
×Fasten the ignition coil lead
(in the sub wire harness) on
the upper inside of the frame
and cut off the tie end.
ãPass the ignition coil lead (in
the sub wire harness) under
the cushion bracket (frame).
ÅFasten the ignition coil lead
(in the sub wire harness) to
the frame with a plastic lock-
ing tie and cut off the tie end.
çPass the carburetor breather
hoses and overflow hose so
that all there hoses do not
contact the rear shock
absorber.