lock YAMAHA YZ426F 2002 Service Manual

4 - 26
ENGCAMSHAFTS
2. Install:
Timing chain tensioner
3. Turn:
Crankshaft
Counterclockwise several turns
4. Check:
Rotor “I” mark
Align with the crankcase stationary
pointer.
Camshaft match marks
Align with the cylinder head surface.
Out of alignment → Adjust.
Install the clips and camshaft caps 4.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
.Tighten the bolts (camshaft cap) 5 in a
crisscross pattern.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly, or damage to the cylinder
head, camshaft caps, and camshaft will
result.
Installation steps:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
With the rod fully wound and the chain
tensioner UP mark a facing upward,
install the gasket 1 and the chain ten-
sioner 2, and tighten the bolt 3 to the
specified torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m • kg, 7.2 ft • lb)
Release the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m • kg, 5.1 ft • lb)

4 - 48
ENGCLUTCH
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
Nut 1
Lock washer 2
Clutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4 to hold the clutch boss.
ÅFor USA and CDN
ıExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
Å
ı
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
Clutch housing 1
Cracks/wear/damage → Replace.
Clutch boss 2
Scoring/wear/damage → Replace.
EC484201
Primary driven gear
1. Check:
Circumferential play
Free play exists → Replace.
Gear teeth a
Wear/damage → Replace.
EC484400
Clutch spring
1. Measure:
Clutch spring free length a
Out of specification → Replace springs
as a set.
Clutch spring free length:
Standard
50 mm (1.97 in) 49 mm (1.93 in)

4 - 50
ENGCLUTCH
EC4A5000
ASSEMBLY AND INSTALLATION
Push lever
1. Install:
Push lever 1
Bolt (push lever)
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Apply the engine oil on the push lever.
Fit the seat plate 2 in the groove a of the
push lever 1 and tighten the bolt (seat
plate).
2
1
a
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Clutch
1. Install:
Primary driven gear 1
Thrust washer 2
Clutch boss 3
NOTE:
Apply the engine oil on the primary driven gear
inner circumference.
2. Install:
Lock washer 1
Nut (clutch boss) 2
NOTE:
Use the clutch holding tool 3 to hold the clutch
boss.
ÅFor USA and CDN
ıExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
New
T R..75 Nm (7.5 m · kg, 54 ft · lb)
Åı

4 - 51
ENG

CLUTCH
3. Bend the lock washer
1
tab.
4. Install:

Seat plate
1

Clutch damper spring
2
NOTE:


Install the seat plate with its chamfered por-
tion
a
facing the clutch boss
3
.

Install the seat plate so that it is not caught
on the step
b
.

Install the clutch damper spring with the
“OUT SIDE” mark
c
facing out.
1
2
c
3
a
b

5. Install:

Friction plate 1 [d = ø128 mm (5.04 in)]
1

Clutch plate
2

Friction plate 2 [d = ø119 mm (4.69 in)]
3
NOTE:


Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.

Use the friction plate 1 for the first while pay-
ing attention to the difference in inner diame-
ter.
1
2
2 1
3
E

6. Install:

Bearing
1


Plain washer
2


Circlip
3

To push rod 1
4
.
NOTE:

Apply the engine oil on the bearing and plain
washer.
New

4 - 60
ENGBALANCER
BALANCER
BALANCER
Extent of removal:1 Balancer drive gear2 Balancer
Extent of removal Order Part name Q’ty Remarks
BALANCER REMOVAL
Preparation for removal Clutch housing Refer to “CLUTCH” section.
Crankcase cover (right)Refer to “OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT)” section.
Stator Refer to “CDI MAGNETO” section.
1 Nut (primary drive gear) 1
Refer to “REMOVAL POINTS”.
2 Nut (balancer) 1
3 Lock washer 1
4 Primary drive gear 1
5 Balancer drive gear 1
6 Lock washer 1
7 Balancer driven gear 1
8 Balancer 1 Refer to “REMOVAL POINTS”.
2
1
2

4 - 61
ENGBALANCER
REMOVAL POINTS
Balancer drive gear and balancer driven
gear
1. Straighten the lock washer tab.
2. Loosen:
Nut (primary drive gear) 1
Nut (balancer) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer drive gear 3 and driven gear
4.
Balancer
1. Remove:
Balancer 1
NOTE:
When removing the balancer shaft, align the
center of the balancer shaft weight a along
the line connecting the centers of the crank-
shaft and balancer shaft.
INSPECTION
Primary drive gear, balancer drive gear and
balancer driven gear
1. Inspect:
Primary drive gear 1
Balancer drive gear 2
Balancer driven gear 3
Wear/damage → Replace.
Balancer
1. Inspect:
Balancer
Cracks/damage → Replace.

4 - 61
ENG

BALANCIER
AUSGLEICHSWELLE
AUSBAU
Ausgleichswellen-Antriebs- und -Abtriebs-
räder
1. Die Lasche der Sicherungsscheibe um-
biegen.
2. Lockern:

Mutter (Primärantriebsrad)
1


Mutter (Ausgleichswelle)
2

HINWEIS:

Ein Stückchen Aluminium
a
zwischen die
Zähne des Ausgleichswellen-Antriebsrades
3
und Ausgleichswellen-Abtriebrades
4
legen.
Ausgleichswelle
1. Demontieren:

Ausgleichswelle
1

HINWEIS:

Beim Ausbau der Ausgleichswelle muß sich
das Ausgleichsgewicht mittig
a
auf der
Fluchtlinie zwischen den Mittelpunkten der
Nockenwellen- und Ausgleichswellen-Enden
befinden.
PRÜFUNG
Primär- und Ausgleichswellen-Antriebs-
und -Abtriebsräder
1. Kontrollieren:

Primärantriebsrad
1


Ausgleichswellen-Antriebsrad
2


Ausgleichswellen-Abtriebsrad
3

Verschleiß/Beschädigung
→
Erneuern.
Ausgleichswelle
1. Kontrollieren:

Ausgleichswelle
Rißbildung/Beschädigung
→
Erneuern.
POINTS DE DEPOSE
Pignon menant et pignon mené du balancier
1. Redresser l’ongle de rondelle d’arrêt.
2. Desserrer:

Ecrou (pignon menant primaire)
1

Ecrou (balancier)
2
N.B.:

Placer une plaque en aluminium
a
entre les dents
du pignon menant
3
et le pignon mené
4
du
balancier.
Balancier
1. Déposer:

Balancier
1
N.B.:

Avant de déposer l’arbre de balancier, aligner le
centre du poids de l’arbre de balancier
a
avec
l’axe reliant le centre du vilebrequin et le centre de
l’arbre de balancier.
CONTROLE
Pignon menant primaire, pignon menant et
pignon mené du balancier
1. Contrôler:

Pignon menant primaire
1

Pignon menant du balancier
2

Pignon mené du balancier
3
Usure/endommagements
→
Remplacer.
Balancier
1. Contrôler:

Balancier
Craquelures/endommagement
→
Rempla-
cer.

4 - 62
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
Balancer 1
NOTE:
When installing the balancer shaft, align the
center of the balancer shaft weight a along
the line connecting the centers of the crank-
shaft and balancer shaft.
2. Install:
Balancer driven gear 1
NOTE:
Install the balancer driven gear onto the bal-
ancer while aligning the punch mark a on the
balancer driven gear with the cut b in the bal-
ancer end.
3. Install:
Balancer drive gear 1
NOTE:
Align the punched mark a on the balancer
drive gear with the punched mark b on the
balancer driven gear.
Align the punched mark c on the balancer
drive gear with the lower spline d on the
crankshaft.
4. Install:
Lock washer 1
Nut (balancer) 2
Primary drive gear 3
Nut (primary drive gear) 4
NOTE:
Install the primary drive gear with its stepped
side b facing the engine.
Place an aluminum plate a between the
teeth of the balancer drive gear 5 and
driven gear 6.
5. Bend the lock washer tab.
T R..50 Nm (5.0 m · kg, 3.6 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)
b3

4 - 69
ENGKICK AXLE AND SHIFT SHAFT
REMOVAL POINTS
EC4B3101
Kick axle assembly
1. Remove:
Kick axle assembly 1
NOTE:
Unhook the torsion spring 2 from the hole a
in the crankcase.
EC4C3101
Shift guide and shift lever assembly
1. Remove:
Bolt (shift guide)
Shift guide 1
Shift lever assembly 2
NOTE:
The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
Bolt (segment) 1
Segment 2
NOTE:
Turn the segment counterclockwise until it
stops and loosen the bolt.
INSPECTION
EC4C4200
Kick axle and ratchet wheel
1. Check:
Ratchet wheel 1 smooth movement
Unsmooth movement → Replace.
Kick axle 2
Wear/damage → Replace.
Spring 3
Broken → Replace.
EC4C4300
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
Kick gear 1
Kick idle gear 2
Ratchet wheel 3
Gear teeth a
Ratchet teeth b
Wear/damage → Replace.

4 - 73
ENGKICK AXLE AND SHIFT SHAFT
3. Install:
Spring guide 1
NOTE:
Slide the spring guide into the kick axle, make
sure the groove a in the spring guide fits on
the stopper of the torsion spring.
4. Install:
Kick axle assembly 1
Plain washer 2
NOTE:
Apply the molybdenum disulfide grease on
the contacting surfaces of the kick axle stop-
per a and stopper plate 3.
Apply the engine oil on the kick axle.
Slide the kick axle assembly into the crank-
case and make sure the kick axle stopper fits
into the stopper plate.
5. Hook:
Torsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
Kick idle gear 1
Plain washer 2
Circlip 3
NOTE:
Install the kick idle gear with its depressed
side a toward you.
Apply the engine oil on the kick idle gear
inner circumference.
New