torque YAMAHA YZ426F 2002 User Guide

4 - 13
ENG
CARBURATEUR
VERGASER
Choke-Schieber
1. Kontrollieren:
Kaltstarter-Tauchkolben 1
Heißstarter-Tauchkolben (rot) 2
Verschleiß/Beschädigung → Erneuern.
Beschleunigungspumpe
1. Kontrollieren:
Membran (Beschleunigungspumpe) 1
Feder 2
Deckel 3
O-Ring 4
Druckstange 5
Rißbildung (Membran)/Beschädigung →
Erneuern.
Schmutz → Säubern.
2. Inspizieren:
Drosselwelle 1
Feder 2
Hebel 1 3
Feder 1 4
Hebel 2 5
Feder 2 6
Schmutz → Säubem
ZUSAMMENBAU UND MONTAGE
Vergaser
1. Montieren:
Heißstarter-Tauchkolben (rot) 1
Kaltstarter-Tauchkolben 2
2. Montieren:
Hauptluftdüse 1
Leerlaufluftdüse 2
O-Ring 3
Ansaugstutzen 4 T R..5 Nm (0,5 m · kg)
Plongeur de starter
1. Contrôler:
Plongeur de démarrage à froid 1
Plongeur de démarrage à chaud (rouge) 2
Usure/endommagement → Remplacer.
Pompe d’accélérateur
1. Contrôler:
Diaphragme (pompe d’accélérateur) 1
Ressort 2
Couvercle 3
Joint torque 4
Tige de commande 5
Déchirure (diaphragme)/endommagement
→ Remplacer.
Sale → Nettoyer.
2. Inspecter:
Axe de papillon 1
Ressort 2
Levier 1 3
Ressort 1 4
Levier 2 5
Ressort 2 6
Sale → Nettoyer
ASSEMBLAGE ET MONTAGE
Carburateur
1. Monter:
Plongeur de démarrage à chaud (rouge) 1
Plongeur de démarrage à froid 2
2. Monter:
Gicleur d’air principal 1
Gicleur d’air de ralenti 2
Joint torque 3
Raccord d’admission 4
T R..5 Nm (0,5 m · kg, 3,6 ft · lb)

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)

5 - 38
CHASFRONT FORK
26. Tighten:
Cap bolt (locknut) 1
NOTE:
While compressing the fork spring, set the
thin type spanners 2 between the spacer 3
and spring guide 4.
Hold the locknut 5 and tighten the cap bolt
with specified torque.
27. Install:
Cap bolt 1
To outer tube.
NOTE:
Temporarily tighten the cap bolt.
T R..29 Nm (2.9 m · kg, 21 ft · lb)
28. Install:
Protector guide 1
Installation
1. Install:
Front fork 1
NOTE:
Temporarily tighten the pinch bolts (under
bracket).
Do not tighten the pinch bolts (handle crown)
yet.
2. Tighten:
Cap bolt 1
3. Adjust:
Front fork top end a
Front fork top end (standard) a:
Zero mm (Zero in)
T R..30 Nm (3.0 m · kg, 22 ft · lb)

5 - 39
CHASFRONT FORK
4. Tighten:
Pinch bolt (handle crown) 1
Pinch bolt (under bracket) 2
ACHTUNG:CAUTION:
Tighten the under bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
5. Install:
Brake hose holder 1
Caliper 2
Bolt (caliper) 3
NOTE:
Fit the brake hose holder cut a over the pro-
jection b on the front fork and clamp the brake
hose.
6. Install:
Brake hose holder 1
Bolt (brake hose holder) 2
Protector 3
Bolt (protector) 4
NOTE:
When installing the brake hose holder, pass
the brake hose 5 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).
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
7. Adjust:
Rebound damping force
NOTE:
Turn in the damping adjuster 1 finger-tight
and then turn out to the originally set position.

5 - 50
CHASSTEERING
9. After tightening the nut, check the steer-
ing for smooth movement. If not, adjust
the steering by loosening the ring nut little
by little.
10. Adjust:
Front fork top end a
Front fork top end (standard) a:
Zero mm (Zero in)
11. Tighten:
Pinch bolt (handle crown) 1
Pinch bolt (under bracket) 2
ACHTUNG:CAUTION:
Tighten the under bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)

7 - 20
TUNSETTING
EC72H002
Suspension setting
Front fork
NOTE:
If any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
Before any change, set the rear shock absorber sunken length to the standard figure 90 ~
100 mm (3.5 ~ 3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff over entire range

Compression damping
Oil level (oil amount)
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with soft spring.
Unsmooth movement
over entire range

Outer tube
Inner tube
Under bracket tightening
torqueCheck for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Retighten to specified torque.
Poor initial
movement

Rebound damping
Oil sealTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Apply grease in oil seal wall.
Soft over entire range,
bottoming out

Compression damping
Oil level (oil amount)
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with stiff spring.
Stiff toward stroke end
Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end,
bottoming out
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial movement
Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture

Compression damping
Rebound damping
Balance with rear end
Oil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tend-
ing to upper front pos-
ture

Compression damping
Balance with rear end
Spring
Oil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when
one passenger is astride seat (upper rear posture).
Replace with soft spring.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).