2006 YAMAHA YZ125LC lock

3-36
STEERING HEAD INSPECTION AND ADJUSTMENT
INSP
ADJ
9Loosen the ring nut one turn.
9Retighten the ring nut using the ring nut
wrench.
w
Avoid over-tightening.
9Check the steering shaft by turning it lock to
lock. If there is any binding, remove the
steering shaft assembly and inspect the
steering bearings.
9Install the plain washer 5, handle crown 6,
plain washer 7, steering shaft nut 8, steer-
ing shaft cap 9, handlebar 0, handlebar
holder (upper) q and number plate w.
NOTE:
9The handlebar holder (upper) should be
installed with the punched mark aforward.
9Install the handlebar so that the marks b
are in place on both sides.
9Insert the end of the fuel breather hose e
into the hole in the steering shaft cap.
cC
First tighten the bolts on the front side of
the handlebar holder (upper), and then
tighten the bolts on the rear side.
Ring nut wrench:
YU-33975/90890-01403
Ring nut (initial tightening):
38 Nm (3.8 m•kg, 27ft•lb)
Steering shaft nut:
145 Nm (14.5 m•kg, 105 t•lb)
Handlebar holder (upper):
28 Nm (2.8 m•kg, 20 ft•lb)
Pinch bolt (handle crown):
23 Nm (2.3 m•kg, 17 ft•lb)
Number plate:
7 Nm (0.7 m•kg, 5.1 ft•lb)
Ring nut (final tightening):
7 Nm (0.7 m•kg, 5.1 ft•lb)
1C3-9-31-3B 4/30/05 3:00 PM Page 36

3-39
IGNITION TIMING CHECK
INSP
ADJ
EC372012
IGNITION TIMING CHECK
1. Remove:
9Fuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
9Spark plug
9Crankcase cover (left)
2. Attach:
9Dial gauge 1
9Spark plug hole dial stand 2
3. Rotate the magneto rotor 1until the
piston reaches top dead center (TDC).
When this happens, the needle on the dial
gauge will stop and reverse directions even
though the rotor is being turned in the same
direction.
4. Set the dial gauge to zero at TDC.
5. From TDC, rotate the rotor clockwise
until the dial gauge indicates that the
piston is at a specified distance from TDC.
6. Check:
9Ignition timing
Punch mark aon rotor should be aligned
with punch mark bon stator.
Not aligned Adjust.
Dial gauge:
YU-3097/90890-01252
Spark plug hole dial stand:
YU-1256
Ignition timing (B.T.D.C.):
0.48 mm (0.019 in)
1C3-9-31-3B 4/30/05 3:00 PM Page 42

4-5
ENGRADIATOR
EC456000
HANDLING NOTE
w
Do not remove the radiator cap when the
engine and radiator are hot. Scalding hot
fluid and steam may be blown out under
pressure, which could cause serious in-
jury.
When the engine has cooled, open the ra-
diator cap by the following procedure:
Place a thick rag, like a towel, over the radi-
ator cap, slowly rotate the cap counter-
clockwise to the detent. This procedure al-
lows any residual pressure to escape.
When the hissing sound has stopped,
press down on the cap while turning coun-
terclockwise and remove it.
EC454000
INSPECTION
EC444100
Radiator
1. Inspect:
9Radiator core 1
Obstruction Blow out with compressed air
through rear of the radiator.
Bent fin Repair/replace.
1C3-9-31-4A 4/28/05 2:36 PM Page 10

4-5
ENG
RADIATEUR
KÜHLER
RADIATORE
HANDHABUNGSHINWEISE
W
Wenn der Motor und der Kühler
heiß sind, darf niemals der Kühler-
deckel entfernt werden. Brühend
heiße Flüssigkeit und Dampf könn-
ten unter hohem Druck herausge-
presst werden, welches zu schwe-
ren Verletzungen führen könnte.
Wenn der Motor abgekühlt ist, den
Kühlerdeckel wie folgt öffnen:
Einen dicken Lappen, wie z.B. ein
Tuch, über den Kühlerdeckel legen,
und danach den Deckel langsam
gegen den Uhrzeigersinn bis zum
Sperrpunkt drehen. Dieser Vorgang
gewährleistet, dass jeder verblei-
bende Restdruck entweichen kann.
Wenn das Zischgeräusch ver-
stummt ist, den Deckel nieder-
drücken und gegen den Uhrzeiger-
sinn drehen, um den Deckel zu ent-
fernen.
INSPEKTION
Kühler
1. Prüfen:
9Kühlerblock 1
VerstopfungMit Druckluft von
Rückseite des Kühlers durch-
blasen.
Verbogene RippeReparie-
ren/Erneuern.
REMARQUES
CONCERNANT LA
MANIPULATION
XG
Ne jamais enlever le bouchon du
radiateur quand le moteur et la
radiateur sont chauds. Du liquide
bouillonnant et de la vapeur risquent
de jaillir sous forte pression, ce qui
est très dangereux.
Quand le moteur est froid, enlever le
bouchon du radiateur en procédant
comme suit:
Quand le moteur est froid, mettre un
chiffon épais tel qu’une serviette sur
ce bouchon puis le tourner lentement
vers la gauche jusqu’au point de
détente. Cette procédure permet
d’éliminer toute pression résiduelle.
Quand le sifflement s’est arrêté,
appuyer sur le bouchon tout en le
tournant vers la gauche puis l’enle-
ver.
VERIFICATION
Radiateur
1. Examiner:
9Carcasse 1
EncrasséNettoyer en soufflant
de l’air comprimé par l’arrière
du radiateur.
TorduRéparer/changer.
IC456000
NOTA PER IL MANEGGIO
T
Non togliere il tappo del radiatore
quando il motore e il radiatore sono
caldi. Sotto pressione possono essere
eruttati liquido e vapore bollenti che
potrebbero provocare lesioni gravi.
Quando il motore si è raffreddato,
aprire il tappo del radiatore con la
procedura che segue:
Collocare uno straccio spesso, come
un asciugamano, sul tappo del radia-
tore, ruotare lentamente il tappo in
senso antiorario fino al fermo. Que-
sta procedura consente all’eventuale
pressione residua di fuoriuscire.
Quando il sibilo si è fermato, preme-
re il tappo verso il basso ruotandolo
in senso antiorario e toglierlo.
IC454000
ISPEZIONE
IC444100
Radiatore
1. Ispezionare:
9Massa radiante 1
OstruzioneSoffiarla fuori con
aria compressa attraverso la
parte posteriore del radiatore.
Aletta piegataRipararla/sosti-
tuirla.
1C3-9-31-4A 4/28/05 2:36 PM Page 11

4-9
ENGCARBURETOR AND REED VALVE
EC466030
HANDLING NOTE
cC
Do not disassemble the venturi block 1 1
and main nozzle 2 2

because it will cause a
drop in carburetor performance.
EC463000
REMOVAL POINTS
EC463110
Throttle valve
1. Remove:
9Throttle valve 1
9Ring 2
9Spring (throttle valve) 3
9Mixing chamber top 4
9Throttle cable 5
NOTE:
While compressing the spring (throttle valve),
disconnect the throttle cable.
EC464000
INSPECTION
EC464140
Carburetor
1. Inspect:
9Carburetor body
Contamination Clean.
cC
When cleaning the main air passage a
a, do
not blow air at the filter side because it will
clog the passage with mud or sand.
NOTE:
9Use a petroleum based solvent for cleaning.
Blow out all passages and jets with com-
pressed air.
9Never use a wire.
9When cleaning the main air passage, blow air
through it while covering the nozzle with a
clean rag.
1C3-9-31-4A 4/28/05 2:36 PM Page 18

4-9
ENG
CARBURATEUR ET SOUPAPE FLEXIBLE
VERGASER UND ZUNGENVENTIL
CARBURATORE E VALVOLA A LAMELLA
HANDHABUNGSHINWEISE
dD
Venturiblock 1 1
und Hauptdüse 2 2
nicht ausbauen, weil dadurch ein
Leistungsabfall beim Vergaser
bewirkt wird.
AUSBAUPUNKTE
Drosselventil
1. Ausbauen:
9Drosselventil 1
9Ring 2
9Feder (Drosselventil) 3
9Mischkammer-Oberteil 4
9Gasseil 5
HINWEIS:
Die Feder zusammendrücken (Dros-
selventil), und das Gasseil abtrennen.
INSPEKTION
Vergaser
1. Prüfen:
9Vergasergehäuse
VerschmutzungReinigen.
dD
Beim Säubern des Hauptluftkanals
a a
darf man keine Luft an der Filter-
seite einblasen, weil dadurch der
Kanal mit Schlamm oder Sand ver-
stopft wird.
HINWEIS:
9Lösungmittel auf Petroleumbasis für
das Reinigen verwenden. Alle
Kanäle und Düsen mit Druckluft
durchblasen.
9Niemals einen Draht verwenden.
9Beim Säubern des Hauptluftkanals
soll man diesen mit Luft durchblasen
und dabei die Düse mit einem sau-
beren Lappen abdecken.
REMARQUES
CONCERNANT LA
MANIPULATION
fF
Ne pas démonter le bloc 1 1
de ventu-
ri et le gicleur principal 2 2
, car cela
provoquerait une réduction des per-
formances du carburateur.
POINTS DE DEPOSE
Boisseau
1. Déposer:
9Boisseau 1
9Bague 2
9Ressort (boisseau) 3
9Haut de chambre de méclange
4
9Cáble d’accélérateur 5
N.B.:
Tout en comprimant le ressort (bois-
seau), déconnecter le câble d’accéléra-
teur.
VERIFICATION
Carburateur
1. Examiner:
9Corps du carburateur
EncrasséNettoyer.
fF
Lors du nettoyage du conduit d’air
principal a a
, ne pas diriger le souffle
d’air comprimé du côté du filtre, car
cela risque d’obstruer le conduit avec
de la boue ou du sable.
N.B.:
9Pour le nettoyage, employer un dis-
solvant à base de pétrole. Passer tous
les conduits et gicleurs à l’air compri-
mé.
9Ne jamais utiliser de fil.
9Lors du nettoyage du conduit d’air
principal, diriger le souffle d’air com-
primé à l’intérieur tout en recouvrant
le gicleur d’un chiffon.
IC466030
NOTA PER IL MANEGGIO
iI
Non smontare il blocco del diffusore
1 1
e l’ugello principale 2 2
perché
questo provocherebbe un calo di ren-
dimento del carburatore.
IC463000
PUNTI DI RIMOZIONE
IC463140
Valvola regolatrice del flusso
1. Togliere:
9Valvola regolatrice del flusso 1
9Anello 2
9Molla (valvola regolatrice del
flusso) 3
9Parte superiore del diffusore 4
9Cavo dell’acceleratore 5
NOTA:
Scollegare il cavo dell’acceleratore
comprimendo la molla (valvola regola-
trice del flusso).
IC464100
ISPEZIONE
IC464140
Carburatore
1. Ispezionare
9Corpo del carburatore
ContaminazionePulirlo.
iI
Quando si pulisce il passaggio
dell’aria principale a a
, non soffiare
aria dal lato del filtro perché ciú
rischia di intasarlo con fango o sab-
bia.
NOTA:
9Per la pulitura, usare un solvente a
base di petrolio. Soffiare tutti i pas-
saggi e i getti con aria compressa.
9Non usare mai un filo metallico.
9Per pulire il passaggio dell’aria princi-
pale, soffiare aria attraverso di esso
coprendo al tempo stesso l’ugello con
un panno pulito.
1C3-9-31-4A 4/28/05 2:36 PM Page 19

4-13
ENGCARBURETOR AND REED VALVE
2. Install:
9Reed valve assembly 1
9Reed valve spacer 2
3. Install:
9Carburetor joint 1
9Bolt (carburetor joint) 2
EC4652C2
Carburetor
1. Install:
9Throttle stop screw 1
9Locknut 2
9Pilot air screw 3
Pilot air screw:
2-1/4 turns out
Note the following installation points:
9Screw in the pilot air screw until it is lightly
seated.
9Back out it by the specified number of turns.
10 Nm (1.0 m•kg, 7.2 ft•lb)
2. Install:
9Starter plunger 1
1C3-9-31-4A 4/28/05 2:36 PM Page 26

4-15
ENGCARBURETOR AND REED VALVE
7. Install:
9Throttle cable 1
9Locknut 2
9Mixing chamber top 3
9Spring (throttle valve) 4
9Ring 5
9Throttle valve 6
NOTE:
9While compressing the spring, connect the
throttle cable.
9Align the projection aon the ring with the
groove bin the needle holder 7.
8. Install:
9Mixing chamber top 1
9Screw (mixing chamber top) 2
To carburetor 3.
NOTE:
After installing, check the throttle grip for smooth
movement.
9. Install:
9Air vent hose 1
9Overflow hose 2
9Clamp 3
NOTE:
Pass the air vent hose at the rear (on the air
cleaner side) of the throttle cable 4.
EC465352
Carburetor installation
1. Install:
9Carburetor 1
NOTE:
Install the projection between the carburetor joint
slots.
4 Nm (0.4 m•kg, 2.9 ft•lb)
1C3-9-31-4A 4/28/05 2:36 PM Page 30