transmission oil YAMAHA YZ426F 2000 Betriebsanleitungen (in German)

CHAPTER 4
ENGINE
SEAT, FUEL TANK AND
SIDE COVERS
.......................................... 4-1
EXHAUST PIPE AND SILENCER
............ 4-3
RADIATOR
................................................ 4-4
CARBURETOR
......................................... 4-7
CAMSHAFTS
.......................................... 4-17
CYLINDER HEAD
................................... 4-24
VALVES AND VALVE SPRINGS
........... 4-27
CYLINDER AND PISTON
....................... 4-35
CLUTCH
.................................................. 4-41
OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT)
............. 4-47
BALANCER
............................................ 4-53
OIL PUMP
............................................... 4-56
KICK AXLE AND SHIFT SHAFT
............ 4-60
CDI MAGNETO
....................................... 4-67
ENGINE REMOVAL
................................ 4-71
CRANKCASE AND CRANKSHAFT
....... 4-76
TRANSMISSION, SHIFT CAM,
SHIFT FORK
........................................... 4-85
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
.............................................. 5-45
SWINGARM
............................................ 5-50
REAR SHOCK ABSORBER
................... 5- 57

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 - 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 520DM-DHA/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 245 ´ 3,0 mm (9,65 ´ 0,12 in) 245 ´ 2,5 mm
(9,65 ´ 0,08 in)
Limite de flèche ----0,15 mm (0,006 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 240 ´ 4,0 mm (9,45 ´ 0,16 in) 240 ´ 3,5 mm
(9,45 ´ 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 82,5 mm (3,25 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) 2 à 4 mm (0,08 à 0,16 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
EC310022
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
cc
OIL FILTER
Replace
cc
VALVES
Check the valve clearances.
Inspect
Replace
cc
c
c
The engine must be cold.
Check the valve seats and
valve stems for wear.
VALVE SPRINGS
Inspect
Replace
c
c
Check the free length and
the tilt.
VALVE LIFTERS
Inspect
Replace
c
c
Check for scratches and
wear.
CAMSHAFTS
Inspect
Replace
c
c
Inspect the camshaft sur-
face.
CAMSHAFT SPROCKETS
Inspect
Replace
c
c
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
cc
c
c
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
c
cc
Check ring end gap
PISTON PIN
Inspect
Replace
c
c
CYLINDER HEAD
Inspect and clean
Retighten
c
Remove carbon
Change gasket
CYLINDER
Inspect and clean
Replace
c
c
Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace
cc
c
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
c
c
3

4 - 49
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4G3000
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
lImpeller 1
lPlain washer 2
lImpeller 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:
lBearing 1
2. Remove:
lOil seal 1
EC4G4000
INSPECTION
EC444200
Impeller shaft
1. Inspect:
lImpeller shaft 1
Bend/wear/damage ® Replace.
Fur deposits ® Clean.

ENG
4 - 78
CRANKCASE AND CRANKSHAFT
CRANKCASE BEARING
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, SHIFT FORK” section.
1 Oil seal 3
2 Bearing 10

4 - 83
ENG

CRANKCASE AND CRANKSHAFT
NOTE:

l
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.
l
Before installing the crankshaft, clean the
contacting surface of crankcase.
CAUTION:

Do not use a hammer to drive in the crank-
shaft.
2. Check:
l
Shifter operation
l
Transmission operation
Unsmooth operation
®
Repair.
3. Install:
l
Oil strainer
1

l
Bolt (oil strainer)
2

T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4. Apply:
l
Sealant
On the crankcase (right)
1
.
NOTE:

Clean the contacting surface of crankcase (left
and right) before applying the sealant.
Quick gasket
®

:
ACC-11001-05-01
Yamaha bond No. 1215:
90890-85505

4 - 84
ENG

CRANKCASE AND CRANKSHAFT
5. Install:
l
Dowel pin
1

lO-ring 2
lCrankcase (right)
To crankcase (left).
NOTE:
lFit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
lWhen installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
6. Tighten:
lHose guide 1
lClutch cable holder 2
lBolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
7. Install:
lOil delivery pipe
lO-ring
lBolt (oil delivery pipe)
8. Install:
lTiming chain
lTiming chain guide (rear)
lPlate washer
lBolt (timing chain guide)
9. Remove:
lSealant
Forced out on the cylinder mating sur-
face.
10. Apply:
lEngine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
lCrankshaft 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)

4 - 87
ENGTRANSMISSION, SHIFT CAM, SHIFT FORK
EC4H4801
Shift fork, shift cam and segment
1. Inspect:
lShift fork 1
Wear/damage/scratches ® Replace.
2. Inspect:
lShift cam 1
lSegment 2
Bend/wear/damage ® Replace.
3. Check:
lShift fork movement
Unsmooth operation ® Replace shift
fork.
NOTE:
For a malfunctioning shift fork, replace not only
the shift fork itself but the two gears each adja-
cent to the shift fork.
EC4H5212
Transmission
1. Install:
l5th pinion gear (21T) 1
l3rd pinion gear (18T) 2
lCollar 3
l4th pinion gear (22T) 4
l2nd pinion gear (18T) 5
To main axle 6.
NOTE:
lApply the molybdenum disulfide oil on the
4th and 5th pinion gears inner circumference
and on the end surface.
lApply the molybdenum disulfide oil on the
2nd and 3rd pinion gears inner circumfer-
ence.

4 - 88
ENGTRANSMISSION, SHIFT CAM, SHIFT FORK
2. Install:
l2nd wheel gear (27T) 1
l4th wheel gear (24T) 2
l3rd wheel gear (23T) 3
l5th wheel gear (20T) 4
l1st wheel gear (24T) 5
lO-ring 6
To drive axle 7.
NOTE:
lApply the molybdenum disulfide oil on the
1st, 2nd and 3rd wheel gears inner circum-
ference and on the end surface.
lApply the molybdenum disulfide oil on the
4th and 5th wheel gears inner circumfer-
ence.
lApply the lithium soap base grease on the O-
ring.
3. Install:
lPlain washer 1
lCirclip 2
NOTE:
lBe sure the circlip sharp-edged corner a is
positioned opposite side to the plain washer
and gear b.
lBe sure the circlip end c is positioned at
axle spline groove d.
New
4. Install:
lSpacer 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lWhen installing the spacer into the crank-
case, pay careful attention to the crankcase
oil seal lip.