2001 YAMAHA YZ426F lock

4 - 25
ENGCAMSHAFTS
2. Install:
lTiming chain tensioner
3. Turn:
lCrankshaft
Counterclockwise several turns
4. Check:
lRotor “I” mark
Align with the crankcase stationary
pointer.
lCamshaft match marks
Align with the cylinder head surface.
Out of alignment ® Adjust.
lInstall the dowel pins, 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:
lWhile pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
lWith 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)
lRelease 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 - 47
ENGCLUTCH
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
lNut 1
lLock washer 2
lClutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4 to hold the clutch boss.
For USA and CDN
õExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086

õ
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
lClutch housing 1
Cracks/wear/damage ® Replace.
lClutch boss 2
Scoring/wear/damage ® Replace.
EC484201
Primary driven gear
1. Check:
lCircumferential play
Free play exists ® Replace.
lGear teeth a
Wear/damage ® Replace.
EC484400
Clutch spring
1. Measure:
lClutch 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
3. Install:
lLock washer 1
lNut (clutch boss) 2
NOTE:
Use the clutch holding tool 3 to hold the clutch
boss.
For USA and CDN
õExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
New
T R..75 Nm (7.5 m · kg, 54 ft · lb)

õ
4. Bend the lock washer 1 tab.
5. Install:
lFriction plate 2 [d = ø119 mm (4.69 in)]
1
lClutch plate 2
NOTE:
lInstall the clutch plates and friction plates 2
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
lApply the engine oil on the friction plates and
clutch plates.
6. Install:
lBearing 1
lPlain washer 2
lCirclip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and plain
washer.
New

4 - 59
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 - 60
ENGBALANCER
REMOVAL POINTS
Balancer drive gear and balancer driven
gear
1. Straighten the lock washer tab.
2. Loosen:
lNut (primary drive gear) 1
lNut (balancer) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer drive gear 3 and driven gear
4.
Balancer
1. Remove:
lBalancer 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:
lPrimary drive gear 1
lBalancer drive gear 2
lBalancer driven gear 3
Wear/damage ® Replace.
Balancer
1. Inspect:
lBalancer
Cracks/damage ® Replace.

4 - 60
ENG
BALANCIER
AUSGLEICHSWELLE
AUSBAU
Ausgleichswellen-Antriebs- und -Abtriebs-
räder
1. Die Lasche der Sicherungsscheibe um-
biegen.
2. Lockern:
lMutter (Primärantriebsrad) 1
lMutter (Ausgleichswelle) 2
HINWEIS:
Ein Stückchen Aluminium a zwischen die
Zähne des Ausgleichswellen-Antriebsrades 3
und Ausgleichswellen-Abtriebrades 4 legen.
Ausgleichswelle
1. Demontieren:
lAusgleichswelle 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:
lPrimärantriebsrad 1
lAusgleichswellen-Antriebsrad 2
lAusgleichswellen-Abtriebsrad 3
Verschleiß/Beschädigung ® Erneuern.
Ausgleichswelle
1. Kontrollieren:
lAusgleichswelle
Rißbildung/Beschädigung ® Erneuern. POINTS DE DEPOSE
Pignon menant et pignon mené du balancier
1. Redresser l’ongle de rondelle d’arrêt.
2. Desserrer:
lEcrou (pignon menant primaire) 1
lEcrou (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:
lBalancier 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:
lPignon menant primaire 1
lPignon menant du balancier 2
lPignon mené du balancier 3
Usure/endommagements ® Remplacer.
Balancier
1. Contrôler:
lBalancier
Craquelures/endommagement ® Rempla-
cer.

4 - 61
ENG

BALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
l
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:
l
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:
l
Balancer drive gear
1

NOTE:

l
Align the punched mark
a
on the balancer
drive gear with the punched mark
b
on the
balancer driven gear.
l
Align the punched mark
c
on the balancer
drive gear with the lower spline
d
on the
crankshaft.
4. Install:
l
Lock washer
1

l
Nut (balancer)
2

l
Primary drive gear
3

l
Nut (primary drive gear)
4

NOTE:

l
Install the primary drive gear with its stepped
side
b
facing the engine.
l
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 - 68
ENGKICK AXLE AND SHIFT SHAFT
REMOVAL POINTS
EC4B3101
Kick axle assembly
1. Remove:
lKick 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:
lBolt (shift guide)
lShift guide 1
lShift lever assembly 2
NOTE:
The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
lBolt (segment) 1
lSegment 2
NOTE:
Turn the segment counterclockwise until it
stops and loosen the bolt.
INSPECTION
EC4C4200
Kick axle and ratchet wheel
1. Check:
lRatchet wheel 1 smooth movement
Unsmooth movement ® Replace.
lKick axle 2
Wear/damage ® Replace.
lSpring 3
Broken ® Replace.
EC4C4300
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
lKick gear 1
lKick idle gear 2
lRatchet wheel 3
lGear teeth a
lRatchet teeth b
Wear/damage ® Replace.