2006 YAMAHA YZ125LC engine

2-3
SPECMAINTENANCE SPECIFICATIONS
Item Standard Limit
Cylinder head:
Combustion chamber capacity 8.4 cm
3…
(0.296 Imp oz, 0.284 US oz)
Warp limit…
0.03 mm (0.0012 in)
Cylinder:
Bore size 54.000~54.014 mm 54.1 mm (2.130 in)
(2.1260~2.1265 in)
Taper limit…
0.05 mm (0.0020 in)
Out of round limit…
0.01 mm (0.0004 in)
Piston:
Piston size/ 53.957~53.972 mm…
(2.1243~2.1249 in)
Measuring point* 17.5 mm (0.69 in)…
Piston clearance 0.040~0.045 mm 0.1 mm (0.004 in)
(0.0016~0.0018 in)
Piston offset 0.5 mm (0.019 in)/EX-side…
Piston pin:
Piston pin outside diameter 14.995~15.000 mm 14.975 mm
(0.5904~0.5906 in) (0.5896 in)
Piston ring:
Sectional sketch Plain…
B=1.0 mm (0.039 in)…
T=2.35 mm (0.093 in)…
End gap (installed) 0.5~0.7 mm (0.020~0.028 in) 1.2 mm (0.047 in)
Side clearance (installed) 0.035~0.070 mm 0.1 mm (0.004 in)
(0.0014~0.0028 in)
Crankshaft:
Crank width “A” 55.90~55.95 mm …
(2.201~2.203 in)
Runout limit “C” 0.03 mm (0.0012 in) 0.05 mm (0.0020 in)
Connecting rod big end
side clearance “D” 0.06~0.64 mm (0.002~0.025 in)…
Small end free play “F” 0.8~1.0 mm (0.031~0.039 in) 2.0 mm (0.08 in)
Clutch:
Friction plate thickness 2.9~3.1 mm (0.114~0.122 in) 2.8 mm (0.110 in)
Quantity 8 …
Clutch plate thickness 1.5~1.7 mm (0.059~0.067 in) …
Quantity 7 …
Warp limit … 0.2 mm (0.008 in)
Clutch spring free length 40.1 mm (1.579 in) 38.1 mm (1.500 in)
Quantity 5 …
Clutch housing thrust clearance 0.15~0.26 mm (0.006~0.010 in) …
Clutch housing radial clearance 0.014~0.046 mm …
(0.0006~0.0018 in)
Clutch release method Inner push, cam push …
EC212000
MAINTENANCE SPECIFICATIONSEC212100
ENGINE
1C3-9-31-2A 4/30/05 2:37 PM Page 4

2-10
SPECMAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q'tyT ightening torqueNm m•kg ft•lb
Rear brake master cylinder and frame M 6 ×1.0 2 10 1.0 7.2
Rear brake master cylinder cap M 4 ×0.7 2 2 0.2 1.4
Rear brake hose union bolt (caliper) M10 ×1.25 1 30 3.0 22
Rear brake hose union bolt (master cylinder) M10 ×1.25 1 30 3.0 22
Rear wheel axle and nut M20 ×1.5 1 125 12.5 90
Nipple (spoke) – 72 3 0.3 2.2
Driven sprocket and wheel hub M 8 ×1.25 6 42 4.2 30
Disc cover and rear brake caliper M 6 ×1.0 2 10 1.0 7.2
Protector and rear brake caliper M 6 ×1.0 2 7 0.7 5.1
Chain puller adjust bolt and locknut M 8 ×1.25 2 16 1.6 11
Engine mounting:
Engine and frame (front) M10 ×1.25 1 64 6.4 46
Engine and frame (lower) M10 ×1.25 1 64 6.4 46
Engine bracket and frame M 8 ×1.25 2 34 3.4 24
Engine bracket and engine M 8 ×1.25 1 34 3.4 24
Pivot shaft and nut M16 ×1.5 1 85 8.5 61
Relay arm and swingarm M14 ×1.5 1 70 7.0 50
Relay arm and connecting rod M14 ×1.5 1 80 8.0 58
Connecting rod and frame M14 ×1.5 1 80 8.0 58
Rear shock absorber and frame M10 ×1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 ×1.25 1 53 5.3 38
Rear frame and frame (upper) M 8 ×1.25 1 32 3.2 23
Rear frame and frame (lower) M 8 ×1.25 2 29 2.9 21
Swingarm and brake hose holder M 5 ×0.8 4 2 0.2 1.4
Swingarm and patch M 4 ×0.7 4 2 0.2 1.4
Chain tensioner mounting M 8 ×1.25 2 16 1.6 11
Chain support and swingarm M 6 ×1.0 3 7 0.7 5.1
Seal guard and swingarm M 5 ×0.8 4 6 0.6 4.3
Cable guide and frame M 5 ×0.8 2 4 0.4 2.9
Fuel tank mounting boss and frame M10 ×1.25 2 20 2.0 14
Fuel tank mounting M 6 ×1.0 2 10 1.0 7.2
Fuel tank and fuel cock M 6 ×1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M 6 ×1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M 6 ×1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M 6 ×1.0 4 7 0.7 5.1
Air scoop and fuel tank M 6 ×1.0 4 7 0.7 5.1
Air scoop and panel M 6 ×1.0 2 6 0.6 4.3
Front fender mounting M 6 ×1.0 4 7 0.7 5.1
Rear fender mounting (front) M 6 ×1.0 2 7 0.7 5.1
Rear fender mounting (rear) M 6 ×1.0 2 12 1.2 8.7
Side cover mounting M 6 ×1.0 2 7 0.7 5.1
Seat mounting M 8 ×1.25 2 19 1.9 13
Number plate M 6 ×1.0 1 7 0.7 5.1
NOTE:

- marked portion shall be checked for torque tightening after break-in or before each race.


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1C3-9-31-2A 4/30/05 2:37 PM Page 11

2-12
SPEC
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS
This chart specifies torque for standard faste-
ners with standard I.S.O. pitch threads. Torque
specifications for special components or assem-
blies are included in the applicable sections of
this book. To avoid warpage, tighten multi-faste-
ner assemblies in a crisscross fashion, in pro-
gressive stages, until full torque is reached.
Unless otherwise specified, torque specifications
call for clean, dry threads. Components should
be at room temperature.
A: Distance across flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
EC220001
GENERAL TORQUE SPECIFICATIONS
A B TORQUE SPECIFICATION
(Nut) (Bolt)
Nm m•kg ft•lb
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13 94
Unit Read Definition Measure
mm milimeter 10-
3meter Length
cm centimeter 10-2meter Length
kg kilogram 103gram Weight
N Newton 1 kg ×m/sec2Force
Nm Newton meter N ×m Torque
m•kg Meter kilogrma m ×kg Torque
Pa Pascal N/m2Pressure
N/mm Newton per millimeter N/mm Spring rate
L Liter — Volume or capacity
cm3Cubic centimeter — Volume or capacity
r/min Revolution per minute — Engine speed
1C3-9-31-2A 4/30/05 2:37 PM Page 13

2-13
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1“ENGINE STOP” button lead
2Throttle cable
3Clutch cable
4Ground lead
5High tension cord
6Clamp
7Air vent hose
8Radiator breather hose
9CDI magneto lead
0YPVS breather hose
qEngine bracket (right)
wEngine bracket (left)
eCrankcase breather hose
rOverflow hose
tConnector coverAPass the clutch cable on the
outside of the throttle cable and
“ENGINE STOP” button lead.
BAlign the throttle cable locating
tape with the cable guide.
CPass the throttle cable, clutch
cable and “ENGINE STOP”
button lead above the radiator
hose.
DInstall the ignition coil, side
core and ground lead together
to the frame. Take care to fas-
ten the ground lead so that its
terminal is within the indicated
range.
EClamp the throttle cable and
high tension cord to the frame.FClamp the clutch cable to the
left engine bracket. Clamp the
clutch cable below the posi-
tioning grommet.
GPass the air vent hose back of
the throttle cable.
HPass the air vent hose, over-
flow hose and crankcase
breather hose between the
frame and connecting rod.
IPass the radiator breather
hose and YPVS breather hose
outside the engine bracket and
inside the down tube. Then
pass the radiator breather
hose inside the YPVS breather
hose.
1C3-9-31-2B 5/11/05 9:50 AM Page 26

2-13
SPEC
SCHEMA DE CHEMINEMENT DES CABLES
KABELFÜHRUNGSÜBERSICHTPLAN
DIAGRAMMA DEL PASSAGGIO DEI CAVI
KABELFÜHRUNGSÜBER-
SICHTPLAN
1„ENGINE STOP“-Schalterkabel
2Gaszug
3Kupplungszug
4Erdungskabel
5Hochspannungskabel
6Klemme
7Belüftungsschlauch
8Kühler-Entlüftungsschlauch
9CDI-Magnetkabel
0YPVS-Entlüftungsschlauch
qMotorhalterung (rechts)
wMotorhalterung (links)
eKurbelgehäuse-Entlüftungsschlauch
rÜberlaufschlauch
tSteckverbinder-Abdeckung
ADen Kupplungszug außen am Gaszug
und am „ENGINE STOP“-Schalterkabel
entlangführen.
BDas Gaszug-Lokalisierungsband an der
Kabelführung ausrichten.
CDen Gaszug, den Kupplungszug und
das „ENGINE STOP“-Schalterkabel
über dem Kühlerschlauch entlang-
führen.
DDie Zündspule, den Seitenkern und das
Erdungskabel zusammen am Rahmen
installieren. Darauf achten, dass das
Erdungskabel angeschlossen wird,
damit sich der Anschluss innerhalb des
angezeigten Bereichs befindet.
EDen Gaszug und das Hochspannungs-
kabel am Rahmen festklammern.
FDen Kupplungszug an der linken Motor-
halterung festklammern. Den Kupp-
lungszug unter der Positionierungsgum-
mitülle festklammern.
GDen Belüftungsschlauch an der Rück-
seite des Gaszugs entlangführen.
HDen Belüftungsschlauch, den Überlauf-
schlauch und den Kurbelgehäuse-Ent-
lüftungsschlauch zwischen dem Rah-
men und der Verbindungsstange ent-
langführen.
IDen Kühler-Entlüftungsschlauch und
den YVPS-Entlüftungsschlauch an der
Außenseite der Motorhalterung und der
Innenseite des Rahmenunterzuges ent-
langführen. Anschließend den Kühler-
Entlüftungsschlauch innerhalb des
YVPS-Entlüftungsschlauches entlang-
führen.
SCHEMA DE
CHEMINEMENT DES
CABLES
1Fil du bouton “ENGINE STOP”
2Câble des gaz
3Câble d’embrayage
4Fil de masse
5Fil haute tension
6Collier à pince
7Durit de ventilation
8Durit de mise à l’air du radiateur
9Fil de magnéto CDI
0Durit de mise à l’air YPVS
qSupport du moteur (droit)
wSupport du moteur (gauche)
eDurit de mise à l’air de carter
rDurit de trop-plein
tCapuchon de connecteur
åFaire passer le câble d’embrayage à
l’extérieur du câble des gaz et du fil du
bouton “ENGINE STOP”.
∫Aligner la bande de positionnement du
câble des gaz sur le guide du câble.
çFaire passer le câble des gaz, le câble
d’embrayage et le fil du bouton “ENGI-
NE STOP” au-dessus de la durit de mise
à l’air du radiateur.
∂Installer la bobine d’allumage, le fais-
ceau latéral et le fil de masse ensemble
sur le cadre. Fixer le fil de masse de
façon à ce que sa borne se trouve dans la
plage indiquée.
´Brider le câble des gaz et le fil haute ten-
sion au cadre.
ƒBrider le câble d’embrayage sur le sup-
port gauche du moteur. Brider le câble
d’embrayage sous l’œillet de positionne-
ment.
©Refaire passer la durit de ventilation du
câble des gaz.
˙Faire passer la durit de ventilation, la
durit de trop-plein et la durit de mise à
l’air du carter moteur entre le cadre et la
bielle.
ˆFaire passer la durit de mise à l’air du
radiateur et la durit de mise à l’air YPVS
à l’extérieur du support du moteur et à
l’intérieur du tube inférieur. Ensuite,
faire passer la durit de mise à l’air du
radiateur à l’intérieur de la durit de mise
à l’air YPVS.
IC240000
DIAGRAMMA DEL
PASSAGGIO DEI CAVI
1Conduttore del pulsante “ARRESTO
MOTORE”
2Cavo acceleratore
3Cavo frizione
4Conduttore di terra
5Cavo alta tensione
6Morsetto
7Flessibile di sfiato aria
8Flessibile di sfiato aria del radiatore
9Cavo magnete CDI
0Flessibile di sfiato YPVS
qStaffa motore (destra)
wStaffa motore (sinistra)
eTubo di sfiato del carter
rFlessibile di troppopieno carburante
tCoperchio del connettore
åFar passare il cavo della frizione dal lato
esterno del cavo dell’acceleratore e del
conduttore del pulsante “ARRESTO
MOTORE”.
∫Allineare il nastro di posizione del cavo
acceleratore con la guida per cavi.
çFar passare il cavo dell’acceleratore, il
cavo della frizione e il conduttore del
pulsante “ARRESTO MOTORE” sopra
il flessibile entrata radiatore.
∂Installare insieme nel telaio la bobina di
accensione, il nucleo laterale e il condut-
tore di terra. Il conduttore di terra deve
essere agganciato in modo tale che il suo
terminale rientri nella gamma indicata.
´Agganciare al telaio il cavo acceleratore
e il cavo alta tensione.
ƒAgganciare il cavo frizione alla staffa
sinistra del motore. Agganciare il cavo
frizione sotto la boccola isolante di posi-
zionamento.
©Passare il flessibile di sfiato aria dietro al
cavo acceleratore.
˙Far passare il flessibile di sfiato aria, il
flessibile di troppopieno carburante e il
flessibile di sfiato del carter tra il telaio e
la biella.
ˆPassare il flessibile di sfiato aria e il fles-
sibile di sfiato YPVS all’esterno della
staffa del motore e dentro il tubo discen-
dente. Quindi passare il flessibile di sfia-
to aria del radiatore dentro il flessibile di
sfiato YPVS.
1C3-9-31-2B 5/11/05 9:50 AM Page 27

2-15
SPECCABLE ROUTING DIAGRAM
1High tension cord
2“ENGINE STOP” button lead
3Ignition coil lead
4Clamp
5CDI unit
6CDI unit band
7Radiator breather hose
8CDI magneto lead
9Connector cover
0Throttle cable
qClutch cable
wCDI unit stay
APass the high tension cord to
the left of the radiator hose.
BUsing a plastic locking tie,
clamp the “ENGINE STOP”
button lead, ignition coil leadand CDI magneto lead togeth-
er with the clamp ends back-
ward and then cut off the tie
end.
CClamp to the frame the throttle
cable, clutch cable, ignition coil
lead and “ENGINE STOP” but-
ton lead. In so doing, clamp
the ignition coil lead and
“ENGINE STOP” button lead at
their protecting tubes. Tighten
the clamp so that the “ENGINE
STOP” button lead is not
pulled when the handlebar is
turned to the right and left.
DPass the CDI magneto lead
and radiator breather hose
between the frame and the
radiator(right).EClamp the CDI magneto lead
to the frame at its locating
tape.
FBring the connector cover into
contact with the coupler.
GLocate the clamp ends in the
arrowed range.
HInsert the CDI unit band until it
stops at the CDI unit stay.
IPass the CDI magneto lead
and radiator breather hose
between the frame and the
radiator hose so that they
come within the arrow-indicat-
ed range. Also take care so
that the CDI magneto lead
passes on the left of the radia-
tor breather hose.
1C3-9-31-2B 5/11/05 9:50 AM Page 30

2-15
SPEC
SCHEMA DE CHEMINEMENT DES CABLES
KABELFÜHRUNGSÜBERSICHTPLAN
DIAGRAMMA DEL PASSAGGIO DEI CAVI
1Hochspannungskabel
2„ENGINE STOP“-Schalterkabel
3Zündspulenkabel
4Klemme
5CDI-Einheit
6CDI-Einheitsband
7Kühler-Entlüftungsschlauch
8CDI-Magnetkabel
9Steckverbinder-Abdeckung
0Gaszug
qKupplungszug
wCDI-Einheitshalterung
ADas Hochspannungskabel links am
Kühlerschlauch vorbeiführen.
BDas „ENGINE STOP“-Schalterkabel,
das Zündspulenkabel und das CDI-
Magnetkabel mit den Enden nach hin-
ten unter Verwendung eines Plastik-
Kabelbinders zusammenklammern und
das Ende des Kabelbinders abschnei-
den.
CDen Gaszug, den Kupplungszug, das
Zündspulenkabel und das „ENGINE
STOP“-Schalterkabel am Rahmen fest-
klammern. Dabei das Zündspulenkabel
und das „ENGINE STOP“-Schalterkabel
an ihren Schutzschläuchen festklam-
mern. Die Klemme festziehen, damit
nicht am „ENGINE STOP“-Schalterka-
bel gezogen werden kann, wenn der
Lenker nach rechts oder nach links
bewegt wird.
DDas CDI-Magnetkabel und den Kühler-
Entlüftungsschlauch zwischen dem
Rahmen und dem Kühler (rechts) ent-
langführen.
EDas CDI-Magnetkabel an seinem Loka-
lisierungsband am Rahmen festklam-
mern.
FDie Steckverbinder-Abdeckung mit dem
Steckverbinder in Kontakt bringen.
GDie Klemmenenden im zulässigen
Bereich anbringen.
HDas CDI-Einheitsband einschieben, bis
es an der CDI-Einheitshalterung stoppt.
IDas CDI-Magnetkabel und den Kühler-
Entlüftungsschlauch zwischen dem
Rahmen und dem Kühlerschlauch ent-
langführen, damit sie sich innerhalb des
angezeigten Bereichs befinden. Auch
darauf achten, dass das CDI-Magnetka-
bel links vom Kühler-Entlüftungs-
schlauch entlanggeführt wird.1Fil haute tension
2Fil du bouton “ENGINE STOP”
3Fil de la bobine d’allumage
4Collier à pince
5Boîtier CDI
6Collier de l’unité CDI
7Durit de mise à l’air du radiateur
8Fil de magnéto CDI
9Capuchon de connecteur
0Câble des gaz
qCâble d’embrayage
wSupport de l’unité CDI
åFaire passer le fil haute tension à gauche
de la durit de mise à l’air du radiateur.
∫A l’aide d’un collier de serrage en plas-
tique, brider le fil du bouton “ENGINE
STOP”, le fil de la bobine d’allumage et
le fil de magnéto CDI ensemble avec les
extrémités du collier vers l’arrière et cou-
per ensuite l’extrémité du collier de ser-
rage.
çBrider sur le cadre le câble des gaz, le
câble d’embrayage, le fil de la bobine
d’allumage et le fil du bouton “ENGINE
STOP”. Pour cela, brider sur leurs tubes
protecteurs le fil de la bobine d’allumage
et le fil du bouton “ENGINE STOP”.
Serrer le collier à pince de façon à ce que
le fil du bouton “ENGINE STOP” ne soit
pas tiré lorsque le guidon tourne vers la
gauche et vers la droite.
∂Faire passer le fil du volant magnétique
CDI et la durit de mise à l’air du radia-
teur entre le cadre et le radiateur (droite).
´Brider le fil de magnéto CDI au cadre sur
sa bande adhésive de positionnement.
ƒMettre le capuchon de connecteur en
contact avec le coupleur.
©Placer les extrémités du collier dans le
sens de la flèche.
˙Insérer la bande de l’unité CDI jusqu’à
ce qu’il s’arrête contre le support de
l’unité CDI.
ˆFaire passer le fil de magnéto CDI et la
durit de mise à l’air du radiateur entre le
cadre et la durit du radiateur de façon à
ce qu’ils se trouvent dans la zone indi-
quée par la flèche. De même, veiller à ce
que le fil de magnéto CDI passe à gauche
de la durit de mise à l’air du radiateur.1Cavo alta tensione
2Conduttore del pulsante “ARRESTO
MOTORE”
3Conduttore bobina d’accensione
4Morsetto
5Unità CDI
6Nastro unità CDI
7Flessibile di sfiato aria del radiatore
8Cavo magnete CDI
9Coperchio del connettore
0Cavo acceleratore
qCavo frizione
wSostegno dell’unità CDI
åPassare il cavo alta tensione a sinistra del
flessibile del radiatore.
∫Usando un serrafili di plastica, aggancia-
re insieme il conduttore del pulsante
“ARRESTO MOTORE”, il conduttore
della bobina d’accensione e il cavo
magnete CDI, con le estremità del mor-
setto rivolte all’indietro, quindi tagliare
l’estremità del serrafili.
çAgganciare al telaio il cavo acceleratore,
il cavo frizione, il conduttore della bobi-
na d’accensione e il conduttore del pul-
sante “ARRESTO MOTORE”. Nel farlo,
agganciare il conduttore della bobina
d’accensione e il conduttore del pulsante
“ARRESTO MOTORE” ai loro tubi di
protezione. Serrare il morsetto in modo
tale che il conduttore del pulsante
“ARRESTO MOTORE” non possa sfug-
gire quando il manubrio ruota a sinistra e
a destra.
∂Passare il conduttore magnete CDI e il
flessibile di sfiato aria del radiatore tra il
telaio e il radiatore (destra).
´Agganciare il conduttore magnete CDI al
telaio, nel punto del nastro di posizione.
ƒPortare il coperchio del connettore a con-
tatto con l’accoppiatore.
©Collocare le estremità del morsetto entro
la gamma indicata dalle frecce.
˙Inserire nel sostegno dell’unità CDI il
nastro dell’unità CDI, finché non si arre-
sta.
ˆPassare il conduttore magnete CDI e il
flessibile di sfiato aria del radiatore tra il
telaio e il flessibile entrata radiatore in
modo da farli stare entro la gamma indi-
cata dalle frecce. Badare inoltre che il
cavo magnete CDI passi a sinistra del
flessibile di sfiato aria del radiatore.
1C3-9-31-2B 5/11/05 9:50 AM Page 31

2-17
SPECCABLE ROUTING DIAGRAM
AInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the master cylinder.
BPass the “ENGINE STOP” button lead in the
middle of the clutch holder.
CClamp the “ENGINE STOP” button lead to the
handlebar to 3 clicks.
DPass the brake hose in front of the number
plate and through the cable guide.
EPass the clutch cable through the cable guide
on the number plate. 1Brake hose
2Master cylinder
3“ENGINE STOP” button lead
4“ENGINE STOP” button
5Throttle cable
6Clutch cable
7Clamp
8Cable guide
1C3-9-31-2B 5/11/05 9:50 AM Page 34