transmission oil YAMAHA YZ426F 2002 Owners Manual

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
EXHAUST PIPE AND SILENCER
............ 4-2
RADIATOR
................................................ 4-4
CARBURETOR
......................................... 4-7
CAMSHAFTS
.......................................... 4-20
CYLINDER HEAD
................................... 4-27
VALVES AND VALVE SPRINGS
........... 4-31
CYLINDER AND PISTON
....................... 4-40
CLUTCH
.................................................. 4-46
OIL FILTER, WATER PUMP
AND CRANKCASE COVER (RIGHT)
.... 4-53
BALANCER
............................................ 4-60
OIL PUMP
............................................... 4-63
KICK AXLE AND SHIFT SHAFT
............ 4-67
CDI MAGNETO
....................................... 4-74
ENGINE REMOVAL
................................ 4-78
CRANKCASE AND CRANKSHAFT
....... 4-83
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
.................................. 4-92
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT BRAKE AND REAR BRAKE
..... 5-10
FRONT FORK
......................................... 5-27
HANDLEBAR
.......................................... 5-40
STEERING
.............................................. 5-46
SWINGARM
............................................ 5-51
REAR SHOCK ABSORBER
................... 5-58

SPEC

2 - 2
GENERAL SPECIFICATIONS
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 8.0 L (1.76 Imp gal, 2.11 US gal)
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: USA, CDN, ZA,
AUS, NZEUROPE
Primary reduction system Gear
←
Primary reduction ratio 62/21 (2.952)
←
Secondary reduction system Chain drive
←
Secondary reduction ratio 49/14 (3.500) 48/14 (3.429)
Transmission type Constant mesh,
5-speed
←
Operation Left foot operation
←
Gear ratio: 1st 24/13 (1.846)
←
2nd 23/15 (1.533)
←
3rd 23/18 (1.278)
←
4th 24/22 (1.091)
←
5th 20/21 (0.952)
←
Chassis:
Frame type Semi double cradle
Caster angle 27.8˚
Trail 123 mm (4.84 in)
Tire:
Type With tube
Size (front) 80/100-21 51M (For USA, CDN, ZA, AUS, NZ
and F)
80/100-21 51R (For EUROPE except F)
Size (rear) 110/90-19 62M (For USA, CDN, ZA, AUS, NZ
and F)
110/90-19 NHS (For EUROPE except F)
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2

, 15 psi)

2

SPEC

2 - 10
MAINTENANCE SPECIFICATIONS
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

2 - 4
CARACTERISTIQUES D’ENTRETIEN
SPEC

CARACTERISTIQUES D’ENTRETIEN
MOTEUR
Article Standard Limite
Culasse:
Limite de déformation ---- 0,05 mm
(0,002 in)
Cylindre:
Alésage 95,00 à 95,01 mm
(3,7402 à 3,7406 in)----
Limite d’ovalisation ---- 0,05 mm
(0,002 in)
Arbre à cames:
Méthode d’entraînement Transmission par chaîne (gauche) ----
Diamètre intérieur de chapeau d’arbre à cames 22,000 à 22,021 mm
(0,8661 à 0,8670 in)----
Diamètre de roulement d’arbre à cames 21,967 à 21,980 mm
(0,8648 à 0,8654 in)----
Jeu entre arbre à cames et chapeau 0,020 à 0,054 mm
(0,0008 à 0,0021 in)0,08 mm
(0,003 in)
Dimensions de came
Admission“A”31,7 à 31,8 mm
(1,2480 à 1,2520 in)31,6 mm
(1,244 in)
“B”22,95 à 23,05 mm
(0,9035 à 0,9075 in)22,85 mm
(0,900 in)
Echappement“A”31,2 à 31,3 mm
(1,2283 à 1,2323 in)31,1 mm
(1,224 in)
“B”22,95 à 23,05 mm
(0,9035 à 0,9075 in)22,85 mm
(0,900 in)
Limite de voile d’arbre à cames ---- 0,03 mm
(0,0012 in)
A
B

2 - 14
CARACTERISTIQUES D’ENTRETIENSPEC
Roue:
Type de roue avant Roue à rayons ----
Type de roue arrière Roue à rayons ----
Taille/matériau de jante avant 21 × 1,60/aluminum ----
Taille/matériau de jante arrière 19 × 2,15/aluminum ----
Limite de voile de jante:
Radial ---- 2,0 mm (0,08 in)
Latéral ---- 2,0 mm (0,08 in)
Chaîne de transmission:
Type/fabricant DID520DMA2 SDH/DAIDO ----
Nombre de maillons 113 maillons + attache ----
Flèche de la chaîne 40 à 50 mm (1,6 à 2,0 in) ----
Longueur de chaîne (10 maillons) ----152,5 mm (6,00 in)
Frein à disque avant:
Diamètre extérieur × épaisseur 250 × 3,0 mm (9,84 × 0,12 in) 250 × 2,5 mm
(9,84 × 0,10 in)
Epaisseur de plaquette 4,4 mm (0,17 in) 1 mm (0,04 in)
Diamètre intérieur de maître-cylindre 11,0 mm (0,433 in) ----
Diamètre intérieur de cylindre d’étrier 27,0 mm (1,063 in) × 2 ----
Type de liquide de frein DOT n˚4 ----
Frein à disque arrière:
Diamètre extérieur × épaisseur 245 × 4,0 mm (9,65 × 0,16 in) 245 × 3,5 mm
(9,65 × 0,14 in)
Limite de flèche ----0,15 mm (0,006 in)
Epaisseur de plaquette 6,4 mm (0,25 in) 1,0 mm (0,04 in)
Diamètre intérieur de maître-cylindre 12,7 mm (0,500 in) ----
Diamètre intérieur de cylindre d’étrier 27,0 mm (1,063 in) × 1 ----
Type de liquide de frein DOT n˚4 ----
Levier de frein et pédale de frein:
Position du levier de frein 95 mm (3,74 in) ----
Hauteur de la pédale de frein
(hauteur en dessous le haut du repose-pied)5 mm (0,20 in) ----
Jeu de levier d’embrayage (au pivot du levier) 8 à 13 mm (0,31 à 0,51 in) ----
Jeu à la poignée d’accélération 3 à 5 mm (0,12 à 0,20 in) ---- Article Standard Limite

3 - 1
INSP
ADJ

MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks
ENGINE OIL
Replace
●

●

OIL FILTER
Clean
●●

VALVES
Check the valve clearances.
Inspect
Replace
●

●

●

●
The engine must be cold.
Check the valve seats
and valve stems for wear.
VALVE SPRINGS
Inspect
Replace
●

●
Check the free length and
the tilt.
VALVE LIFTERS
Inspect
Replace
●

●
Check for scratches and
wear.
CAMSHAFTS
Inspect
Replace
●

●
Inspect the camshaft sur-
face.
CAMSHAFT SPROCKETS
Inspect
Replace
●

●
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
●

●

●

●
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
●

●

●
Check ring end gap
PISTON PIN
Inspect
Replace
●

●

CYLINDER HEAD
Inspect and clean
●
Remove carbon
Change gasket
CYLINDER
Inspect and clean
Replace
●

●
Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace
●

●

●
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
●

●

4 - 55
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
Impeller 1
Plain washer 2
Impeller shaft 3
NOTE:
Hold the impeller shaft on its width across the
flats a with spanners, etc. and remove the
impeller.
EC4G3210
Oil seal
NOTE:
It is not necessary to disassemble the water
pump, unless there is an abnormality such as
excessive change in coolant level, discolora-
tion of coolant, or milky transmission oil.
1. Remove:
Bearing 1
Oil seal 2
INSPECTION
EC444200
Impeller shaft
1. Inspect:
Impeller shaft 1
Bend/wear/damage → Replace.
Fur deposits → Clean.

4 - 85
ENGCRANKCASE AND CRANKSHAFT
CRANKCASE BEARING
Extent of removal:1 Crankcase bearing removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE BEARING
REMOVAL
Preparation for removal Transmission
Shift cam and shift forkRefer to “TRANSMISSION, SHIFT
CAM AND SHIFT FORK” section.
1 Oil seal 3
2 Bearing 10 Refer to “REMOVAL POINTS”.
1

4 - 90
ENGCRANKCASE AND CRANKSHAFT
NOTE:
Hold the connecting rod at top dead center
with one hand while turning the nut of the
installing tool with the other. Operate the
installing tool until the crankshaft bottoms
against the bearing.
Before installing the crankshaft, clean the
contacting surface of crankcase.
CAUTION:
Do not use a hammer to drive in the crank-
shaft.
2. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.
3. Install:
Oil strainer 1
Bolt (oil strainer) 2
4. Apply:
Sealant
On the crankcase (right) 1.
NOTE:
Clean the contacting surface of crankcase (left
and right) before applying the sealant.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 91
ENGCRANKCASE AND CRANKSHAFT
5. Install:
Dowel pin 1
O-ring 2
Crankcase (right)
To crankcase (left).
NOTE:
Fit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
When installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
6. Tighten:
Hose guide 1
Clutch cable holder 2
Bolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
7. Install:
Oil delivery pipe
O-ring
Bolt (oil delivery pipe)
8. Install:
Timing chain
Timing chain guide (rear)
Bolt (timing chain guide)
9. Remove:
Sealant
Forced out on the cylinder mating sur-
face.
10. Apply:
Engine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
Crankshaft and transmission operation.
Unsmooth operation → Repair.
New
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)