2002 YAMAHA WR 426F oil

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SPECGENERAL SPECIFICATIONS (WR426F)
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS (WR426F)
Model name: WR426FP (USA)
WR426F (EUROPE)
WR426F(P) (CDN, AUS, NZ, ZA)
Model code number: 5NG5 (USA)
5NG6 (EUROPE)
5NG8 (CDN, AUS, NZ, ZA)
Dimensions:
Overall length 2,171 mm (85.5 in)
Overall width 827 mm (32.6 in)
Overall height 1,303 mm (51.3 in)
Seat height 998 mm (39.3 in)
Wheelbase 1,490 mm (58.7 in)
Minimum ground clearance 373 mm (14.7 in)
Basic weight:
With oil and full fuel tank 121.5 kg (268 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 426 cm
3 (15.0 Imp oz, 14.4 US oz)
Bore × stroke 95.0 × 60.1 mm (3.74 × 2.37 in)
Compression ratio 12.5 : 1
Starting system Kick starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil
(For USA and CDN)
At 5 ˚C (40 ˚F) or higher Å
Yamalube 4 (20W-40) or SAE 20W-40 type SH
motor oil (Non-Friction modified)
At 15 ˚C (60 ˚F) or lower ı
Yamalube 4 (10W-30) or SAE 10W-30 type SH
motor oil (Non-Friction modified) and/or
Yamalube 4-R (15W-50) (Non-Friction modified)
(Except for USA and CDN)
API “SH” or higher grade
-20
-4-10
140
3010
5020
6830
8640 50
104
122°CTemp.
°F
10W-30
10W-40
20W-40
20W-50
15W-40

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SPECGENERAL SPECIFICATIONS (WR426F)
Oil capacity:
Engine oil
Periodic oil change 1.3 L (1.14 Imp qt, 1.37 US qt)
With oil filter replacement 1.4 L (1.23 Imp qt, 1.48 US qt)
Total amount 1.5 L (1.32 Imp qt, 1.59 US qt)
Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a
research octane number of 95 or higher.
(Except for ZA)
Premium gasoline (For ZA)
Tank capacity 12 L (2.64 Imp gal, 3.17 US gal)
(For USA, CDN, AUS and NZ)
8.0 L (1.76 Imp gal, 2.11 US gal)
(For EUROPE and ZA)
Reserve 1.6 L (0.35 Imp gal, 0.42 US gal)
(For USA, CDN, AUS and NZ)
1.4 L (0.31 Imp gal, 0.37 US gal)
(For EUROPE and ZA)
Carburetor:
Type FCR-MX39
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK
U24ESR-N/DENSO
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 62/21 (2.952)
Secondary reduction system Chain drive
Secondary reduction ratio 50/14 (3.571)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 29/12 (2.416)
2nd 26/15 (1.733)
3rd 21/16 (1.312)
4th 21/20 (1.050)
5th 21/25 (0.840)
Chassis:
Frame type Semi double cradle
Caster angle 27.8˚
Trail 123 mm (4.84 in)

2

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SPECGENERAL 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 kgf/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
Headlight type: Quartz bulb (halogen)
Bulb wattage × quantity:
Headlight 12 V 60/55 W × 1
Tail light 12 V 21/5 W × 1

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SPECMAINTENANCE SPECIFICATIONS (WR426F)
Piston rings:
Top ring
Type Barrel ----
Dimensions (B × T) 1.2 × 3.5 mm (0.05 × 0.14 in) ----
End gap (installed) 0.20 ~ 0.30 mm
(0.008 ~ 0.012 in)0.55 mm
(0.022 in)
Side clearance (installed) 0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)0.12 mm
(0.005 in)
2nd ring
Type Taper ----
Dimensions (B × T) 1.00 × 3.35 mm (0.04 × 0.13 in) ----
End gap (installed) 0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)0.85 mm
(0.033 in)
Side clearance 0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)0.12 mm
(0.005 in)
Oil ring
Dimensions (B × T) 2.0 × 2.9 mm (0.08 × 0.11 in) ----
End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----
Crankshaft:
Crank width “A”61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)----
Runout limit “C”0.03 mm (0.0012 in) 0.05 mm
(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 mm
(0.08 in)
Balancer:
Balancer drive method Gear ----
Decompression device:
Type Manual ----
Cable free play 5 ~ 9 mm (0.20 ~ 0.35 in)
Air filter oil grade: Engine oil ----Item Standard Limit
T
B
B
T
B
T

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SPECMAINTENANCE 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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SPECMAINTENANCE 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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SPECMAINTENANCE SPECIFICATIONS (WR426F)
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S × 1.0 1 13 1.3 9.4
Camshaft cap M6 × 1.0 10 10 1.0 7.2
Cylinder head (stud bolt) M6 × 1.0 2 7 0.7 5.1
M8 × 1.25 3 15 1.5 11
(bolt) M10 × 1.25 4 44 4.4 32
(nut) M6 × 1.0 2 10 1.0 7.2
M8 × 1.25 2 20 2.0 14
Cylinder head cover M6 × 1.0 2 10 1.0 7.2
Cylinder M6 × 1.0 1 10 1.0 7.2
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Tensioner cap bolt M6 × 1.0 1 7 0.7 5.1
Timing chain guide (rear) M6 × 1.0 2 10 1.0 7.2
Decompression shaft M6 × 1.0 1 7 0.7 5.1
Decompression cable guide M6 × 1.0 1 10 1.0 7.2
Exhaust pipe (nut) M8 × 1.25 1 13 1.3 9.4
(bolt) M8 × 1.25 1 24 2.4 17
Silencer M8 × 1.25 2 35 3.5 25
Silencer clamp M8 × 1.25 1 20 2.0 14
Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
Spark arrester (for USA) M6 × 1.0 3 10 1.0 7.2
Silencer end pipe (for USA) M6 × 1.0 1 10 1.0 7.2
Clamp (air cleaner joint) M5 × 0.8 1 3 0.3 2.2
Clamp (carburetor joint) M4 × 0.7 1 3 0.3 2.2
Air filter joint clamp M6 × 1.0 1 3 0.3 2.2
Throttle cable cover M5 × 0.8 1 4 0.4 2.9
Air filter element M6 × 1.0 1 2 0.2 1.4
Air filter case cover M6 × 1.0 4 4 0.4 2.9
Radiator panel (upper) M6 × 1.0 2 10 1.0 7.2
Radiator M6 × 1.0 6 10 1.0 7.2
Radiator hose clamp M6 × 1.0 8 2 0.2 1.4
Impeller M8 × 1.25 1 14 1.4 10
Water pump housing cover M6 × 1.0 3 10 1.0 7.2
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Oil pump cover M5 × 0.8 1 4 0.4 2.9
Oil pump M6 × 1.0 3 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 × 1.0 1 10 1.0 7.2
Oil filter cover M6 × 1.0 2 10 1.0 7.2
Oil delivery pipe 1 M10 × 1.25
M8 × 1.251
220
182.0
1.814
13
Oil hose clamp—2 2 0.2 1.4
Clutch cover M6 × 1.0 7 10 1.0 7.2
Crankcase cover (right) M6 × 1.0 10 10 1.0 7.2
Crankcase cover (left) M6 × 1.0 8 10 1.0 7.2
Crankcase M6 × 1.0 12 12 1.2 8.7

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SPECMAINTENANCE SPECIFICATIONS (WR426F)
Oil drain bolt (crankcase) M12 × 1.5 1 20 2.0 1.4
Oil drain bolt (frame) M8 × 1.25 1 23 2.3 17
Oil strainer (frame) M18 × 1.5 1 90 9.0 65
Crankcase bearing stopper M6 × 1.0 15 10 1.0 7.2
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kick crank M8 × 1.25 1 33 3.3 24
Primary drive gear M20 × 1.0 1 75 7.5 54
Clutch boss M20 × 1.0 1 75 7.5 54
Clutch spring M6 × 1.0 6 8 0.8 5.8
Balancer driven gear M14 × 1.0 1 50 5.0 36
Balancer weight plate M6 × 1.0 3 10 1.0 7.2
Drive sprocket M20 × 1.0 1 75 7.5 54
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22
Neutral switch M5 × 0.8 2 4 0.4 2.9 Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.