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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 82 of 762
2 - 9
SPEC
MAINTENANCE SPECIFICATIONS (WR426F)
Lubrication system:
Oil filter type Wire mesh type ----
Oil pump type Trochoid type ----
Tip clearance “A” 0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Tip clearance “B” 0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Side clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.007 in)
Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm
2
,
5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width 117.8 mm (4.6 in) ----
Height 260 mm (10.2 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure110 kPa (1.1 kg/cm
2
, 15.6 psi)----
Radiator capacity (total) 0.76 L (0.67 lmp qt, 0.80 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
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2 - 10
SPEC
MAINTENANCE SPECIFICATIONS (WR426F)
Item Standard
Lubrication chart:
Pressure feed
Splashed scavenge
Oil strainer
Oil pan Oil pump rotor 2
Oil pump rotor 1
Oil tank
Oil filter
Check ball
Cylinder head
Crank pinPiston pinPiston
Drive axleMain axleTransmission gears
Camshaft
Valve lifter
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2 - 13
SPECMAINTENANCE SPECIFICATIONS (WR426F)
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN
AUS, NZ, ZAEUROPE
Front fork travel 300 mm
(11.8 in)¬----
Fork spring free length 460 mm
(18.1 in)¬455 mm (17.9 in)
Spring rate, STD K = 4.51 N/mm
(0.46 kg/mm,
25.8 lb/in)K = 4.12 N/mm
(0.42 kg/mm,
23.5 lb/in)----
Optional spring/spacer Yes¬----
Oil capacity 573 cm
3
(20.2 lmp oz,
19.4 US oz) 583 cm3
(20.5 lmp oz,
19.7 US oz)----
Oil level 135 mm
(5.31 in)125 mm
(4.92 in)----
(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)80 ~ 150 mm
(3.15 ~ 5.91 in)¬----
Oil grade Suspension oil
“01”¬----
Inner tube outer diameter 46 mm (1.81 in)¬----
Front fork top end Zero mm
(Zero in)¬----
Rear suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Shock absorber travel 132 mm
(5.20 in)¬----
Spring free length 260 mm
(10.24 in)¬----
Fitting length 241 mm
(9.49 in)244 mm
(9.61 in)----
240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)¬----
Spring rate, STD K = 49.0 N/mm
(5.00 kg/mm,
280.0 lb/in)K = 47.0 N/mm
(4.80 kg/mm,
268.8 lb/in)----
Optional spring Yes¬----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)¬----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)
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SPECMAINTENANCE SPECIFICATIONS (WR400F)
Lubrication system:
Oil filter type Wire mesh type ----
Oil pump type Trochoid type ----
Tip clearance “A” 0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Tip clearance “B” 0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Side clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.007 in)
Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm
2,
5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width 117.8 mm (4.6 in) ----
Height 260 mm (10.2 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure110 kPa (1.1 kg/cm
2, 15.6 psi)----
Radiator capacity (total) 0.76 L (0.67 lmp qt, 0.80 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
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SPECMAINTENANCE SPECIFICATIONS (WR400F)
Item Standard
Lubrication chart:
Pressure feed
Splashed scavenge
Oil strainer
Oil pan Oil pump rotor 2
Oil pump rotor 1
Oil tank
Oil filter
Check ball
Cylinder head
Crank pinPiston pinPiston
Drive axleMain axleTransmission gears
Camshaft
Valve lifter
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2 - 30
SPECMAINTENANCE SPECIFICATIONS (WR400F)
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN
AUS, NZ, ZAEUROPE
Front fork travel 300 mm
(11.8 in)¬----
Fork spring free length 460 mm
(18.1 in)¬455 mm (17.9 in)
Spring rate, STD K = 4.51 N/mm
(0.46 kg/mm,
25.8 lb/in)K = 4.12 N/mm
(0.42 kg/mm,
23.5 lb/in)----
Optional spring/spacer Yes¬----
Oil capacity 573 cm
3
(20.2 lmp oz,
19.4 US oz) 583 cm3
(20.5 lmp oz,
19.7 US oz)----
Oil level 135 mm
(5.31 in)125 mm
(4.92 in)----
(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)80 ~ 150 mm
(3.15 ~ 5.91 in)¬----
Oil grade Suspension oil
“01”¬----
Inner tube outer diameter 46 mm (1.81 in)¬----
Front fork top end Zero mm
(Zero in)¬----
Rear suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Shock absorber travel 132 mm
(5.20 in)¬----
Spring free length 260 mm
(10.24 in)¬----
Fitting length 241 mm
(9.49 in)244 mm
(9.61 in)----
240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)¬----
Spring rate, STD K = 49.0 N/mm
(5.00 kg/mm,
280.0 lb/in)K = 47.0 N/mm
(4.80 kg/mm,
268.8 lb/in)----
Optional spring Yes¬----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)¬----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)
Page 228 of 762
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INSP
ADJ
MAINTENANCE INTERVALS
* marked: For USAFRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
c
cc
c
c
Suspension oil “01”
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
cc
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
c
cc
cc
(After
rain ride)
c
Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
cc
SWINGARM
Inspect and retighten
cc
RELAY ARM, CONNECTING ROD
Inspect and lube
cc
Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
cc
c
c
Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
c
cc
c
c
cc
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
c
cc
c
Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
race
Every
third
or
500 km
(300 mi)Every
fifth
or
1,000 km
(600 mi)
As re-
quiredRemarks