2000 YAMAHA YZ426F height

SPEC

2 - 1
GENERAL SPECIFICATIONS
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: YZ426FLC (EUROPE)
YZ426FM (USA)
YZ426F(M) (CDN, AUS, NZ, ZA)
Model code number: 5JG1 (USA)
5JG2 (EUROPE)
5JG4 (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 113.5 kg (250 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 SAE 20W40 SH or SAE 10W30 SH
Oil capacity:
Engine oil
Periodic oil change 1.5 L (1.32 Imp qt, 1.59 US qt)
With oil filter replacement 1.6 L (1.41 Imp qt, 1.69 US qt)
Total amount 1.7 L (1.50 Imp qt, 1.80 US qt)
Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
-20
-4-10
140
3010
5020
6830
8640 50
104
122¡CTemp.
¡F
10W/30
10W/40
20W/40
20W/50

2

SPEC

2 - 8
MAINTENANCE SPECIFICATIONS
Clutch:
Friction plate thickness 2.9 ~ 3.1 mm
(0.114 ~ 0.122 in)2.7 mm
(0.11 in)
Quantity 9 ----
Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in) ----
Quantity 8 ----
Warp limit ---- 0.1 mm
(0.004 in)
Clutch spring free length 44 mm (1.73 in) 43 mm
(1.69 in)
Quantity 6 ----
Clutch housing thrust clearance 0.20 ~ 0.45 mm
(0.0079 ~ 0.0177 in)----
Clutch housing radial clearance 0.010 ~ 0.044 mm
(0.0004 ~ 0.0017 in)----
Clutch release method Inner push, cam push ----
Shifter:
Shifter type Cam drum and guide bar ----
Guide bar bending limit ---- 0.05 mm
(0.002 in)
Kick starter:
Type Ratchet type ----
Carburetor:
USAEUROPE, CDN,
ZA, AUS, NZ
I. D. mark 5JG1 00 5JG2 10 ----
Main jet (M.J) #162
¬
----
Main air jet (M.A.J) #200
¬
----
Jet needle (J.N) OBEKR-4 OBEKQ-4 ----
Cutaway (C.A) 15
¬
----
Pilot air jet 1 (P.A.J.1) #100
¬
----
Pilot outlet (P.O) 0.9
¬
----
Pilot jet (P.J) #42
¬
----
Pilot screw (example) (P.S) 1-3/4 1-1/2 ----
Bypass 1 (B.P.1) 1.0
¬
----
Valve seat size (V.S) 3.8
¬
----
Starter jet 1 (G.S.1) #72
¬
----
Float height (F.H) 8 mm (0.31 in)
¬
----
Engine idle speed 1,700 ~
1,900 r/min
¬
----
Intake vacuum29.3 ~ 32.0 kPa
(220 ~ 240 mmHg,
8.66 ~ 9.45 inHg)
¬
---- Item Standard Limit

SPEC

2 - 9
MAINTENANCE SPECIFICATIONS
Lubrication system:
Oil filter type Wire mesh type ----
Oil pump type Trochoid type ----
Tip clearance “A” or “B” 0.07 ~ 0.12 mm
(0.0028 ~ 0.0047 in)0.15 mm
(0.006 in)
Side clearance 0.03 ~ 0.08 mm
(0.0012 ~ 0.0031 in)0.15 mm
(0.006 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

SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 21 ´ 1.60/Aluminum ----
Rear rim size/material 19 ´ 2.15/Aluminum ----
Rim runout limit:
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/manufacturer 520DM-DHA/DAIDO ----
Number of links 113 links + joint ----
Chain slack 40 ~ 50 mm (1.6 ~ 2.0 in) ----
Chain length (10 links) ----152.5 mm (6.00 in)
Front disc brake:
Disc outside dia. ´ Thickness 245 ´ 3.0 mm (9.65 ´ 0.12 in) 245 ´ 2.5 mm
(9.65 ´ 0.08 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 4.4 mm (0.17 in) 1 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 2 ----
Brake fluid type DOT #4 ----
Rear disc brake:
Disc outside dia. ´ Thickness 240 ´ 4.0 mm (9.45 ´ 0.16 in) 240 ´ 3.5 mm
(9.45 ´ 0.14 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 6.4 mm (0.25 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 12.7 mm (0.500 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 1 ----
Brake fluid type DOT #4 ----
Brake lever and brake pedal:
Brake lever position 82.5 mm (3.25 in) ----
Brake pedal height
(vertical height below footrest top)5 mm (0.20 in) ----
Clutch lever free play (at lever pivot) 2 ~ 4 mm (0.08 ~ 0.16 in) ----
Throttle grip free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----Item Standard Limit

3 - 2
INSP
ADJ

MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
c
Inspect wear
ROTOR NUT
Retighten
cc
MUFFLER
Inspect
Clean
Replace
cc
cc
* Whichever comes first
CRANK
Inspect and clean
cc
CARBURETOR
Inspect, adjust and clean
cc
When using a high-pres-
sure washer, make sure
that water does not enter
the accelerator pump.
SPARK PLUG
Inspect and clean
Replace
cc
c
DRIVE CHAIN
Lubricate, slack, alignment
Replace
cc
c
Use chain lube
Chain slack: 40~50 mm
(1.6~2.0 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
cc
cc
c
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
cc
Refer to “STARTING AND
BREAK-IN” section in the
CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
cc
c
Use foam air-filter oil
OIL STRAINER (frame)
Clean
c
FRAME
Clean and inspect
cc
FUEL TANK, COCK
Clean and inspect
cc
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid
c
c
c
c
cc
c
c
c
c
c
c
Every one year
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
c
cc
c
c
Suspension oil “01” ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks
3

3 - 26
INSP
ADJREAR BRAKE ADJUSTMENT/
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
EC364002
REAR BRAKE ADJUSTMENT
1. Check:
lBrake pedal height a
Out of specification ® Adjust.
Brake pedal height a:
5 mm (0.20 in)
2. Adjust:
lBrake pedal height
EC365080
FRONT BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
lBrake pad thickness a
Out of specification ® Replace as a
set.
2. Replace:
lBrake pad Pedal height adjustment steps:
lLoosen the locknut 1.
lTurn the adjusting nut 2 until the pedal
height a is within specified height.
lTighten the locknut.
Brake pad thickness a:
Standard
4.4 mm (0.17 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
lRemove the pad pin plug 1.
õ
WARNING
lAdjust the pedal height between the
maximum and the minimum õ as
shown. (In this adjustment the bolt 3
end b should protrude out of the lower
adjusting nut 4 but not be less than 2
mm (0.08 in) c away from the brake
pedal 5).
lAfter the pedal height adjustment, make
sure that the rear brake does not drag.

4 - 12
ENGCARBURETOR
EC464511
Float height
1. Measure:
lFloat height a
Out of specification ® Adjust.
Float height:
8.0 mm (0.31 in)
Measurement and adjustment steps:
lHold the carburetor in an upside down
position.
lMeasure the distance between the mating
surface of the float chamber and top of the
float using a vernier calipers.
lIf the float height is not within specifica-
tion, inspect the valve seat and needle
valve.
lIf either is worn, replace them both.
lIf both are fine, adjust the float height by
bending the float tab b on the float.
lRecheck the float height.
NOTE:
lSlowly tilt the carburetor in the opposite
direction, then take the measurement
when the needle valve aligns with the float
arm.
lIf the carburetor is level, the weight of the
float will push in the needle valve, result-
ing in an incorrect measurement.
NOTE:
The float arm should be resting on the nee-
dle valve, but not compressing the needle
valve.
EC464600
Float
1. Inspect:
lFloat 1
Damage ® Replace.

5 - 23
CHASFRONT BRAKE AND REAR BRAKE
3. Install:
lSpring 1
lBrake pedal 2
lO-ring 3
lBolt (brake pedal) 4
lClip 5
NOTE:
lApply the lithium soap base grease on the
bolt, O-ring and brake pedal bracket.
lInstall the clip with its stopper portion a fac-
ing inward.
New
T R..19 Nm (1.9 m · kg, 13 ft · lb)
4. Install:
lPin 1
lPlain washer 2
lCotter pin 3
NOTE:
After installing, check the brake pedal height.
Refer to “REAR BRAKE ADJUSTMENT” sec-
tion in the CHAPTER 3.
New
EC5A5900
Front brake hose
1. Install:
lBrake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
pass the brake hose in front of the axle boss
a, then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
2. Install:
lHose cover 1
lPlain washer 2
lBolt [hose cover (M8)] 3
lBolt [hose cover (M6)] 4
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)