2005 YAMAHA YZ125LC oil

3-37
LUBRICATION
INSP
ADJ
EC36a042
LUBRICATION
To ensure smooth operation of all components,
lubricate your machine during setup, after break-
in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Throttle roller sliding surface
8Tube guide cable winding portion
9Throttle cable end
0Clutch cable endÅUse Yamaha cable lube or equivalent on
these areas.
ıUse SAE10W-30 motor oil or suitable chain
lubricants.
ÇLubricate the following areas with high quali-
ty, lightweight lithium-soap base grease.
cC
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
A
A
CC
AB
AA
1C3-9-30-3B 17/5/04 1:22 PM Page 38

4-12
ENG
CARBURATEUR ET SOUPAPE FLEXIBLE
VERGASER UND ZUNGENVENTIL
CARBURATORE E VALVOLA A LAMELLA
9Altezza del fermo della valvola
b
Fuori specificaRegolare fermo
/Sostituire fermo della valvola.
IC465000
MONTAGGIO E
INSTALLAZIONE
IC465190
Valvola a lamella
1. Installare:
9Valvola a lamella 1
9Fermo (valvola a lamella) 2
9Vite (valvola a lamella) 3
NOTA:
9Installare la valvola a lamella con la
curvatura della valvola a lamella
come illustrato.
9Notare il taglio anell’angolo inferio-
re della lamella e della piastra del
fermo.
iI
Serrare gradualmente ciascuna vite
per evitare svergolamenti.
9Ventilanschlaghöhe b
Abweichung von Spezifikation
Anschalg einstellen/ Ven-
tilanschlag erneuern.
MONTAGE UND EINBAU
Zungenventil
1. Einbauen:
9Zungenventil 1
9Anschlag (Zungenventil) 2
9Schraube (Zungenventil) 3
HINWEIS:
9Das Zungenventil so einbauen, daß
die Biegung des Zungenventils
gemäß Abbildung angeordnet ist.
9Es ist darauf zu achten, daß der
Ausschnitt aan der unteren Ecke
der Ventilzunge richtig am Ventilan-
schag positioniert.
dD
Die Schrauben allmählich festzie-
hen, um ein Verziehen des Ventils
zu vermeiden.
9Hauteur de la butée de soupape
b
Hors spécification Régler/
changer la butée de clapet.
REMONTAGE ET
MONTAGE
Soupape flexible
1. Monter:
9Soupape flexible 1
9Butée (soupape flexible) 2
9Vis (soupape flexible) 3
N.B.:
9Mettre la lame soupape avec la cour-
bure de lame soupape de la manière
indiquée.
9Noter l’entaille adans le coin infé-
rieur de la soupape et de la plaque de
butée.
fF
Serrer les vis granduellement pour
éviter de voiler le dispositif.
Ventilanschlaghöhe:
8,2~8,6 mm
(0,323~0,339 in)
1 Nm (0,1 m•kg, 0,7 ft•lb)
Altezza del fermo della
valvola:
8,2~8,6 mm
(0,323~0,339 in)
1 Nm (0,1 m•kg, 0,7 ft•lb)
1 Nm (0,1 m•kg, 0,7 ft•lb)
Hauteur de la butée de
soupape:
8,2~8,6 mm
(0,323~0,339 in)
IC464701Valvola a lamella
1. Misurare:
9Curvatura della valvola a lamel-
la a
Fuori specificaSostituirla.Zungenventil
1. Messen:
9Verbiegung des Zungenventils
a
Abweichung von Spezifikation
Erneuern. Schwimmer
1. Prüfen:
9Schwimmer 1
BeschädigungErneuern.
Flotteur
1. Examiner:
9Flotteur 1
EndommagementChanger.
Soupape flexible
1. Mesurer:
9Torsion de la soupape flexible
a
Hors spécificationChanger.IC464600Galleggiante
1. Ispezionare
9Galleggiante 1
DanniSostituirlo.
Verbiegungsgrenze des
Zungenventils:
0,2 mm (0,008 in)Limite di curvatura della
valvola a lamella:
0,2 mm (0,008 in)Limite de torsion de la
soupape flexible:
0,2 mm (0,008 in)
1C3-9-30-4A 25/5/04 7:23 PM Page 25

4-20
ENG
CULASSE, CYLINDRE ET PISTON
ZYLINDERKOPF, ZYLINDER UND KOLBEN
TESTA CILINDRO, CILINDRO E PISTONE
INSPEKTION
Zylinderkopf
1. Entfernen:
9Ölkohleablagerungen
Einen abgerundeten Schaber
1verwenden.
HINWEIS:
Dabei vorsichtig vorgehen, damit das
Gewinde der Zündkerzenbohrung
nicht beschädigt wird. Niemals scharf-
kantige Werkzeuge verwenden, um
ein Zerkratzen des Aluminiums zu
vermeiden.
2. Prüfen:
9Zylinderkopf-Kühlwasserman-
tel
Wasserstein/RostEntfernen.
9Zylinderkopf-Verwerfung
Abweichnung von Spezifikation
Bearbeitung der Oberfläche.
Zylinder
1. Entfernen:
9Ölkohleablagerungen
Einem abgerundeten Schaber
verwenden 1.
HINWEIS:
Kein scharfkantiges Instrument ver-
wenden. Kratzer auf dem Aluminium
vermeiden.
VERIFICATION
Culasse
1. Éliminer:
9Depôts de carbone
Utiliser le grattoir arrondi 1.
N.B.:
Prendre garde à ne pas rayer le filetage
du trou de bougie et les sièges de sou-
pape. Ne pas utiliser d’instrument poin-
tu. Eviter de rayer l’aluminium.
2. Examiner:
9Chemise d’eau de la culasse
Couche de minéraux/rouille
Eliminer.
9Déformation de la culasse
Hors-spécificationRectifier.
IC474002
ISPEZIONE
IC474102
Testa cilindro
1. Eliminare:
9Depositi carboniosi
Usare un raschietto arrotondato
1.
NOTA:
Fare attenzione a evitare di danneggiare
le filettature della candela. Non usare
uno strumento appuntito. Evitare di
graffiare l’alluminio.
2. Ispezionare:
9Camicia d’acqua della testa
cilindro
Crosta di
minerali/RuggineToglierle.
9Svergolamento della testa cilin-
dro
Fuori specificaRispianare e
rifinire la superficie.
Schritte für Messung der Ver-
werfung und Bearbeitung der
Oberfläche:
9Am Zylinderkopf ein Lineal 1
und Einstell-Lehre 2anbringen.
9Die Verwerfungsgrenze messen.
9Wenn die Verwerfung nicht den
erforderlichen Maßen entspricht,
Zylinderkopffläche bearbeiten.
9Ein feuchtes Sandpapier 3
(Feinheit 400~600) auf die Ober-
flächenplatte legen und den
Zylinderkopf 4durch Aus-
führung einer Achterfigur
abschleifen.
HINWEIS:
Um zu vermeiden, daß an einer
Seite zu viel abgeschliffen wird,
den Zylinderkopf mehrmals dre-
hen.
Verwerfungsgrenze:
0,03 mm (0,0012 in)
Passi della misurazione e la
rispianatura e rifinitura della
superficie dello svergolamento:
9Collegare alla testa cilindro un
guardapiano 1e uno spessimetro
2.
9Misurare lo svergolamento.
9Se lo svergolamento è fuori speci-
fica, rispianare e rifinire la super-
ficie della testa cilindro.
9Collocare carta vetrata umida di
grana no. 400~600 3sul piano di
riscontro e rispianare e rifinire la
superficie della testa 4usando
uno schema di carteggiatura a
forma di otto.
NOTA:
Ruotare la testa cilindro diverse
volte per evitare di togliere troppo
materiale da un lato.
Limite di svergolamento:
0,03 mm (0,0012 in)
Procédure mesure de la déforma-
tion et rectification:
9Poser une règle 1et un calibre
d’épaisseur 2sur la culasse.
9Mesurer la déformation.
9Si la déformation est hors-spécifi-
cation, rectifier la culasse.
9Mettre un morceau de toile émeri
humide de N°400~600 3sur un
marbre et rectifier la culasse 4en
lui faisant faire des “huit”.
N.B.:
Tourner la culasse plusieurs fois
pouréviter d’enlever trop de matière
d’un côté.
Limite de déformation:
0,03 mm (0,0012 in)
Cylindre
1. Éliminer:
9Dépôts du carbone
Utiliser le grattoir arrondi 1.
N.B.:
Eviter d’utiliser un outil acéré, éviter de
rayer l’aluminium.
IC474201Cilindro
1. Eliminare:
9Depositi carboniosi
Usare un raschietto arrotondato
1.
NOTA:
Non usare uno strumento appuntito.
Evitare di graffiare l’alluminio.
1C3-9-30-4B 25/5/04 7:20 PM Page 7

4-26
ENGCYLINDER HEAD, CYLINDER AND PISTON
2. Install:
9Spring 1
9Link lever 2
9Collar 3
9Valve shaft 4
9Valve holder 5
9Bolt (link lever) 6
NOTE:
9Install the spring to the link lever, and then to
the cylinder.
9Install the spring with its stopper portion afac-
ing inward.
9Apply the lithium soap base grease on the oil
seal lip.
3. Install:
9Thrust plate 1
9Screw (thrust plate) 2
4. Check:
9Power valve smooth movement
Unsmooth movement Repair or replace.
5. Install:
9Gasket (power valve cover) 1
9Power valve cover 2
9Screw (power valve cover) 3
9YPVS breather hose 4
NOTE:
9Install the power valve cover so that the arrow
mark afaces upward.
9Install the clamp of the YPVS breather hose
with its opening portion bfacing backward.
4 Nm (0.4 m•kg, 2.9 ft•lb)
4 Nm (0.4 m•kg, 2.9 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
1C3-9-30-4B 25/5/04 7:20 PM Page 18

4-27
ENGCYLINDER HEAD, CYLINDER AND PISTON
EC475280
Piston ring and piston
1. Install:
9Piston ring 1
NOTE:
9Take care not to scratch the piston or damage
the piston ring.
9Align the piston ring gap with the pin 2.
9After installing the piston ring, check the
smooth movement of it.
2. Install:
9Gasket (cylinder) 1
9Small end bearing 2
9Dowel pin 3
NOTE:
9Apply the engine oil onto the bearing (crank-
shaft and connecting rod) and connecting rod
big end washers.
9Install the gasket with the seal print side toward
the crankcase.
3. Install:
9Piston 1
9Piston pin 2
9Piston pin clip 3
NOTE:
9The arrow aon the piston dome must point to
exhaust side.
9Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the pis-
ton pin clip from falling into the crankcase cavi-
ty.
cC
9When installing the piston pin clip, use
the hand so that it may not be distorted.
9Do not allow the clip open ends to meet
the piston pin slot b.
1C3-9-30-4B 25/5/04 7:20 PM Page 20

4-28
ENGCYLINDER HEAD, CYLINDER AND PISTON
3. Install:
9Nut (cylinder) 1
NOTE:
Tighten the nuts in stage, using a crisscross pat-
tern.
4. Install:
9Collar 1
9Push rod 2
9Plain washer 3
9Bolt (push rod) 4
NOTE:
9Set the collar 5included in owner's tool kit to
install the bolt (push rod).
9Do not forget to remove the collar.
EC4753A2
Cylinder head and cylinder
1. Apply:
9Engine oil
To piston 1, piston ring 2and cylinder
surface.
2. Install:
9Cylinder 1
cC
Make sure the piston ring is properly posi-
tioned. Install the cylinder with one hand
while compressing the piston ring with the
other hand.
NOTE:
After installing, check the smooth movement of
the piston.
30 Nm (3.0 m•kg, 22 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
1C3-9-30-4B 25/5/04 7:20 PM Page 22

4-30
CLUTCH AND PRIMARY DRIVEN GEARENG
Extent of removal Order Part name Q’ty Remarks
CLUTCH PLATE AND
FRICTION PLATE REMOVAL
Preparation for Drain the transmission oil.
Refer to “TRANSMISSION OIL REPLACE-
removalMENT“ section in the CHAPTER 3.
Bolt (brake pedal) Shift the brake pedal downward.
Rotor and stator Refer to
“CDI MAGNETO“section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Screw (clutch spring) 6
3 Clutch spring 6
4 Pressure plate 1
5 Friction plate 8
6 Clutch plate 7
Extent of removal:1Clutch plate and friction plate removal
EC490000
CLUTCH AND PRIMARY DRIVEN GEAREC498000
CLUTCH PLATE AND FRICTION PLATE
1
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
1C3-9-30-4B 25/5/04 7:20 PM Page 26

4-33
CLUTCH AND PRIMARY DRIVEN GEARENG
EC484500
Friction plate
1. Measure:
9Friction plate thickness
Out of specification Replace friction
plate as a set.
Measure at all four points.
EC484600
Clutch plate
1. Measure:
9Clutch plate warpage
Out of specification Replace clutch plate
as a set.
Use a surface plate 1and thickness
gauge 2.
EC484700
Push lever axle
1. Inspect:
9Push lever axle 1
Wear/Damage Replace.
EC484810
Push rod
1. Inspect:
9Push rod 1 1
9Bearing 2
9Plain washer 3
9Push rod 2 4
9Ball 5
Wear/Damage/Bend Replace.
EC495000
ASSEMBLY AND INSTALLATION
EC485120
Push lever axle
1. Install:
9Push lever axle 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip and push lever axle.
Friction plate thickness:
Standard
2.9~3.1 mm 2.8 mm
(0.114~0.122 in) (0.110 in)
Warp limit:
0.2 mm (0.008 in)
1C3-9-30-4B 25/5/04 7:20 PM Page 32