2004 YAMAHA YZ250LC engine

1-1
DESCRIPTION
BESCHREIBUNG
DESCRIZIONE
GEN
INFO
ALLGEMEIN
ANGABEN
BESCHREIBUNG1Kupplungshebel
2Motorstoppknopf „ENGINE STOP“
3Handbremshebel
4Gasdrehgriff
5Kühlerdeckel
6Kraftstofftank-Verschluß
7Kickstarter
8Kraftstofftank
9Kühler
0Kühlmittel-Ablaßschraube
qPrüfschraube (Getriebeölstand)
wFußbremshebel
eVentilverbindung
rKraftstoffhahn
tStarterknopf
yAntriebskette
uLuftfilter
iSchalthebel
oVorderradgabel
HINWEIS:
9Die von Ihnen gekaufte Maschine
könnte etwas von den hier gezeigten
Abbildungen abweichen.
9Anderungen des Designs und der
Technischen Daten ohne vorherge-
hende Bekanntgage vorbehalten.
RENSEIGNEMENTS
GENERAUX
DESCRIPTION1Levier d’embrayage
2Bouton de coupe-circuit de sécurité
“ENGINE STOP”
3Levier de frein avant
4Poignée d’accélérateur
5Bouchon du radiateur
6Bouchon de réservoir à essence
7Kickstarter
8Réservoir de carburant
9Radiateur
0Boulon de vidange du liquide de
refroidissement
qBoulon de contrôle
(niveau d’huile de transmission)
wPédale de frein arrière
eJoint de robinet
rRobinet à essence
tBouton de starter
yChaîne de transmission
uFiltre à air
iPédale de sélecteur
oFourche avant
N.B.:
9La machine que vous avez achetée
diffère peutêtre partiellement de celles
montrées sur ces photos.
9La conception et les caractéristiques
peuvent êtres changées sans préavis.
IC100000
INFORMAZIONI
GENERALI
IC110000
DESCRIZIONE
1Leva di comando della frizione
2Pulsante “ARRESTO MOTORE”
3Leva di comando del freno anteriore
4Manopola dell’acceleratore
5Tappo del radiatore
6Tappo del serbatoio del carburante
7Pedivella della messa in moto
8Serbatoio del carburante
9Radiatore
0Bullone di drenaggio del liquido
refrigerante
qBullone di controllo
(livello dell’olio della trasmissione)
wPedale di comando del freno posteriore
eGiunto della valvola
rRubinetto del carburante
tManopola dell’avviamento
yCatena di trasmissione
uFiltro dell’aria
iPedale del cambio
oForcella anteriore
NOTA:
9Il veicolo acquistato può essere leg-
germente diverso da quelli illustrati
qui sotto.
9Progetti e specifiche sono soggetti a
variazioni senza preavviso.
1
5XF-9-30-1 4/22/03 8:54 AM Page 3

GEN
INFO
1-2
MACHINE IDENTIFICATION
EC120001
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number of your machine:
1. When ordering parts, you can give the num-
ber to your Yamaha dealer for positive iden-
tification of the model you own.
2. If your machine is stolen, the authorities will
need the number to search for and identify
your machine.
EC121001
VEHICLE IDENTIFICATION NUMBER
(For USA, CDN, AUS, NZ and E)
The vehicle identification number 1is stamped
on the right of the steering head pipe.
EC122001
FRAME SERIAL NUMBER
(For F, D, GB, I and ZA)
The frame serial number 1is stamped on the
right of the steering head pipe.
EC123001
ENGINE SERIAL NUMBER
The engine serial number 1is stamped into the
elevated part of the right-side of the engine.
EC124000
MODEL LABEL
The model label 1is affixed to the frame under
the rider’s seat. This information will be needed
to order spare parts.
5XF-9-30-1 4/22/03 8:54 AM Page 4

1-4
IMPORTANT INFORMATION
GEN
INFO
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should be
replaced when an engine is overhauled. All
gasket surfaces, oil seal lips, and O-rings
must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
EC134000
LOCK WASHERS/PLATES AND COTTER
PINS
1. All lock washers/plates 1and cotter pins
must be replaced when they are removed.
Lock tab(s) should be bent along the bolt or
nut flat(s) after the bolt or nut has been
properly tightened.
EC135001
BEARINGS AND OIL SEALS
1. Install the bearing (s) 1and oil seal (s) 2
with their manufacturer’s marks or numbers
facing outward. (In other words, the
stamped letters must be on the side
exposed to view.) When installing oil seal(s),
apply a light coating of light-weight lithium
base grease to the seal lip(s). Oil the bear-
ings liberally when installing.
cC
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.
EC132000
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha genuine
parts for all replacements. Use oil and/or
grease recommended by Yamaha for
assembly and adjustment.
5XF-9-30-1 4/22/03 8:54 AM Page 8

1-8
SPECIAL TOOLS
GEN
INFO
Part number Tool name / How to use IIIustration
YU-33975, 90890-01403 Ring nut wrenchYU-33975 90890-01403
This tool is used when tighten the steering ring nut
to specification.
YM-01442, 90890-01442 Fork seal driver
YM-01442 90890-01442
This tool is used when install the fork oil seal.
YM-01494, 90890-01494 Damper rod holder
YM-01494 90890-01494
Use this tool to remove and install the damper rod.
YU-3112-C, 90890-03112 Yamaha pocket tester
YM-3112-C 90890-03112
Use this tool to inspect the coil resistance,
output voltage and amperage.
YU-8036-B Inductive tachometer
YU-8036-B 90890-03113
90890-03113 Engine tachometer
This tool is needed for observing engine rpm.
YM-91042, 90890-04086 Clutch holding tool
YM-91042 90890-04086
This tool is used to hold the clutch when removing
or installing the clutch boss securing nut.
YM-34487 Dynamic spark tester
YM-34487 90890-06754
90890-06754 Ignition checker
This instrument is necessary for checking the igni-
tion system components.
ACC-QUICK-GS-KT Quick gasket
®ACC-QUICK-GS-KT 90890-85505
90890-85505 YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.
5XF-9-30-1 4/22/03 8:54 AM Page 15

1-9
CONTROL FUNCTIONS
GEN
INFO
EC150000
CONTROL FUNCTIONS
EC151000
“ENGINE STOP” BUTTON
The “ENGINE STOP” button 1is located on the
left handlebar. Continue pushing the “ENGINE
STOP” button till the engine comes to a stop.
EC152000
CLUTCH LEVER
The clutch lever 1is located on the left handle-
bar; it disengages or engages the clutch. Pull
the clutch lever to the handlebar to disengage
the clutch, and release the lever to engage the
clutch. The lever should be pulled rapidly and
released slowly for smooth starts.
EC153000
SHIFT PEDAL
The gear ratios of the constant-mesh 5 speed
transmission are ideally spaced. The gears can
be shifted by using the shift pedal 1on the left
side of the engine.
EC154000
KICK STARTER
Rotate the kick starter 1away from the engine.
Push the starter down lightly with your foot until
the gears engage, then kick smoothly and force-
fully to start the engine. This model has a prima-
ry kick starter so the engine can be started in
any gear if the clutch is disengaged. In normal
practices, however, shift to neutral before start-
ing.
EC155001
THROTTLE GRIP
The throttle grip 1is located on the right han-
dlebar; it accelerates or decelerates the engine.
For acceleration, turn the grip toward you; for
deceleration, turn it away from you.
5XF-9-30-1 4/22/03 8:54 AM Page 22

1-9
FONCTIONS DES COMMANDES
BEDIENUNGSELEMENTE
FUNZIONI DEI COMANDI
GEN
INFO
FONCTIONS DES
COMMANDES
BOUTON D’ARRET DE MOTEUR
“ENGINE STOP”
Ce bouton d’arrêt de moteur “ENGINE
STOP” 1est situé sur le guidon
gauche. Continuer à appuyer sur le bou-
ton d’arrêt de moteur “ENGINE STOP”
jusqu’a que ce le moteur s’arrête.
LEVIER D’EMBRAYAGE
Le levier d’embrayage 1est situé sur
le guidon gauche et permet d’embrayer
ou de débrayer. Tirer le levier
d’embrayage vers le guidon pour
débrayer et relâcher le levier pour
embrayer. Pour des démarrages doux,
le levier doit être tiré rapidement et
relâché lentement.
PEDALE DE CHANGEMENT DE
VITESSE
Les 5 rapports pour de la boîte de
vitesses à prise constante sont idéale-
ment échelonnés. Le changement de
vitesse est commandé par le sélecteur à
pédale 1situé du côté gauche du
moteur.
KICKSTARTER
Déployer la pédale de démarreur au
pied 1. Appuyer légèrement sur la
pédale jusqu’à ce que les pignons se
mettent en prise puis l’actionner vigou-
reusement pour démarrer le moteur. Ce
modèle est muni d’un démarreur au
pied primaire, de sorte qu’on peut
démarrer sur n’importe quelle vitesse à
condition de débrayer. Toutefois, nor-
malement, on remettra les vitesses au
point mort avant la mise en marche.
POIGNEE DES GAZ
La poignée des gaz 1est située sur le
guidon droit; elle permet d’accélérer ou
de décélérer le moteur. Pour une accé-
lération, tourner la poignée vers soi;
pour une décélération, la tourner de
l’autre côté.
BEDIENUNGSELEMENTE
MOTORSTOPPKNOPF „ENGINE
STOP“
Dieser Motorstoppknopf „ENGINE
STOP“ 1befindet sich am linken
Lenkerrohr.
Den Motorstoppknopf „ENGINE
STOP“ drücken, bis der Motor
abstirbt.
KUPPLUNGSHEBEL
Der Kupplungshebel 1befindet sich
am linken Lenkerrohr und dient zum
Aus- bzw. Einrücken der Kupplung.
Den Kupplungshebel bis zum Lenker-
rohr durchziehen, um die Kupplung
auszurücken; den Hebel wieder frei-
geben, sobald die Kupplung wieder
eingerückt werden soll. Der Hebel
sollte schnell durchgezogen, aber
langsam freigegeben werden, um ein
ruckfreies Anfahren zu gewährleisten.
FUSSSCHALTHEBEL
Das Untersetzungsverhältnis dieses 5
Gang Synchrongetriebes ist optimal
abgestimmt, um bestes Leistungsver-
mögen bei allen Fahrbedingungen zu
garantieren. Das Einlegen der einzel-
nen Gänge erfolgt mittels Fußschalt-
hebel 1, angebrancht an der linken
Seite des Motors.
KICKSTARTER
Den Kickstarter 1vom Motor weg-
schwenken. Den Kickstarter langsam
niedertreten, bis die Zahnräder einra-
sten; danach den Kickstarter
schwungvoll durchtreten, um den
Motor anzulassen. Dieses Modell ist
mit einem Primärkickstarter ausgerü-
stet, d.h. der Motor kann auch bei ein-
gelegtem Gang angelassen werden,
vorausgesetzt, daß die Kupplung aus-
gerückt wird. Normalerweise sollte
jedoch in den Leerlauf geschaltet wer-
den, bevor der Motor gestartet wird.
GASDREHGRIFF
Der Gasdrehgriff 1ist am rechten
Lenkerrohr angeordnet; mit diesem
Gasdrehgriff wird die Drehzahl des
Motors erhöht bzw. reduziert. Für eine
Drehzahlerhöhung (Beschleunigung)
den Gasdrehgriff gegen sich drehen,
wogegen für eine Drehzahlreduzie-
rung der Gasdrehgriff von sich wegge-
dreht werden muß.
IC150000
FUNZIONI DEI COMANDI
IC151000
PULSANTE “ARRESTO
MOTORE”
Il pulsante “ARRESTO MOTORE” 1
è situato sul manubrio sinistro. Conti-
nuare a premere il pulsante “ARRE-
STO MOTORE” finché il motore non
si arresta.
IC152000
LEVA DI COMANDO DELLA
FRIZIONE
La leva di comando della frizione 1è
situata sul manubrio sinistro; disinnesta
o innesta la frizione. Tirare la leva di
comando della frizione verso il manu-
brio per disinnestare la frizione e lascia-
re andare la leva per innestare la frizio-
ne. La leva dovrebbe essere tirata rapi-
damente e lasciata andare lentamente
per partenze dolci.
IC153000
PEDALE DI COMANDO DEL
CAMBIO
I rapporti di trasmissione della trasmis-
sione a 5 marce a ingranamento costan-
te sono distanziati in maniera ideale. Si
possono cambiare le marce usando il
pedale di comando del cambio 1sul
lato sinistro del motore.
IC154000
PEDIVELLA DELLA MESSA IN
MOTO
Ruotare la pedivella della messa in
moto 1allontanandola dal motore.
Spingere leggermente la pedivella verso
il basso con il piede finché le marce
non si innestano, quindi scalciare senza
strappi e con forza per avviare il moto-
re. Questo modello ha una pedivella
primaria della messa in moto, quindi il
motore può essere avviato in qualsiasi
marcia se la frizione è disinnestata.
Nella prassi normale, però, mettere in
folle prima di avviare.
IC155001
MANOPOLA DELL’ACCELERA-
TORE
La manopola dell’acceleratore 1è
situata sul manubrio destro; accelera o
decelera il motore. Per l’accelerazione,
ruotare la manopola verso il guidatore;
per la decelerazione, ruotarla lontano
dal guidatore.
5XF-9-30-1 4/22/03 8:54 AM Page 23

1-10
CONTROL FUNCTIONS
GEN
INFO
EC156000
FRONT BRAKE LEVER
The front brake lever 1is located on the right
handlebar. Pull it toward the handlebar to acti-
vate the front brake.
EC157000
REAR BRAKE PEDAL
The rear brake pedal 1is located on the right
side of the machine. Press down on the brake
pedal to activate the rear brake.
EC158001
FUEL COCK
The fuel cock supplies fuel from the tank to car-
buretor while filtering the fuel. The fuel cock has
the two positions:
OFF: With the lever in this position, fuel will not
flow. Always return the lever to this posi-
tion when the engine is not running.
ON: With the lever in this position, fuel flows to
the carburetor. Normal riding is done with
the lever in this position.
EC159000
STARTER KNOB (CHOKE)
When cold, the engine requires a richer air-fuel
mixture for starting. A separate starter circuit,
which is controlled by the starter knob 1, sup-
plies this mixture. Pull the starter knob out to
open the circuit for starting. When the engine
has warmed up, push it in to close the circuit.
5XF-9-30-1 4/22/03 8:54 AM Page 24

1-11
CONTROL FUNCTIONS
GEN
INFO
EC15F000
VALVE JOINT
This valve joint 1prevents fuel from flowing out
and is installed to the fuel tank breather hose.
cC
In this installation, make sure the arrow
faces the fuel tank and also downward.
EC15R001
DETACHABLE SIDESTAND
This sidestand 1is used to support only the
machine when standing or transporting it.
w
9Never apply additional force to the side-
stand.
9Remove this sidestand before starting
out.
EC15f000
SET PIN
This set pin 1is used to remove and install the
push rod of the engine.
cC
Be sure to use the set pin. If the set pin is
not used, the power valve constituent parts
will result in damage.
EC15e000
NIPPLE WRENCH
This nipple wrench 1is used to tighten the
spoke.
5XF-9-30-1 4/22/03 8:54 AM Page 26