2003 YAMAHA YZ250F radiator

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS ................................. 4-1
EXHAUST PIPE AND SILENCER ............ 4-3
RADIATOR ................................................ 4-5
CARBURETOR ......................................... 4-8
CAMSHAFTS .......................................... 4-21
CYLINDER HEAD ................................... 4-30
VALVES AND VALVE SPRINGS ........... 4-33
CYLINDER AND PISTON ....................... 4-42
CLUTCH .................................................. 4-49
OIL FILTER ELEMENT, WATER PUMP
AND RIGHT CRANKCASE COVER ...... 4-56
BALANCER ............................................ 4-63
OIL PUMP ............................................... 4-66
KICK SHAFT AND SHIFT SHAFT .......... 4-71
CDI MAGNETO ....................................... 4-78
ENGINE REMOVAL ................................ 4-82
CRANKCASE AND CRANKSHAFT ....... 4-87
TRANSMISSION, SHIFT CAM
AND SHIFT FORK .................................. 4-96
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL ...... 5-1
FRONT BRAKE AND REAR BRAKE ..... 5-10
FRONT FORK ......................................... 5-26
HANDLEBAR .......................................... 5-39
STEERING .............................................. 5-45
SWINGARM ............................................ 5-50
REAR SHOCK ABSORBER ................... 5-58

KAPITEL 4
MOTOR
SITZBANK, KRAFTSTOFFTANK
UND SEITENABDECKUNGEN .. 4-1
KRÜMMER
UND SCHALLDÄMPFER ........... 4-3
KÜHLER ..................................... 4-5
VERGASER ................................ 4-8
NOCKENWELLE ...................... 4-21
ZYLINDERKOPF ...................... 4-30
VENTILE
UND VENTILFEDERN ............. 4-33
ZYLINDER UND KOLBEN ....... 4-42
KUPPLUNG .............................. 4-49
ÖLFILTEREINSATZ, WASSER-
PUMPE UND RECHTE KURBEL-
WELLENABDECKUNG ........... 4-56
AUSGLEICHSWELLE .............. 4-63
ÖLPUMPE ................................ 4-66
KICKSTARTER UND KICKSTAR-
TERWELLE .............................. 4-71
CDI-SCHWUNGRADMAGNETZÜN-
DER .......................................... 4-78
MOTOR DEMONTIEREN ......... 4-82
KURBELGEHÄUSE UND KURBEL-
WELLE ..................................... 4-87
GETRIEBE, SCHALTWALZE UND
SCHALTGABELN .................... 4-96
KAPITEL 5
FAHRWERK
VORDER- UND HINTERRAD .... 5-1
VORDER-
UND HINTERRADBREMSE .... 5-10
TELESKOPGABEL .................. 5-26
LENKER ................................... 5-39
LENKKOPF .............................. 5-45
SCHWINGE .............................. 5-50
FEDERBEIN ............................. 5-58
CHAPITRE 4
MOTEUR
SELLE, RESERVOIR
DE CARBURANT ET CACHES
LATERAUX .................................... 4-1
TUYAU D’ECHAPPEMENT
ET SILENCIEUX ........................... 4-3
RADIATEUR .................................. 4-5
CARBURATEUR ........................... 4-8
ARBRES A CAMES ..................... 4-21
CULASSE ...................................... 4-30
SOUPAPES ET
RESSORTS DE SOUPAPE ......... 4-33
CYLINDRE ET PISTON ............. 4-42
EMBRAYAGE .............................. 4-49
ELEMENT DE FILTRE
A HUILE, POMPE A EAU ET
DEMI-CARTER DROIT ............. 4-56
BALANCIER ................................ 4-63
POMPE A HUILE ........................ 4-66
ARBRE DE KICK
ET ARBRE DE SELECTEUR .... 4-71
VOLANT MAGNETIQUE
CDI ................................................. 4-78
DEPOSE DU MOTEUR .............. 4-82
CARTER ET VILEBREQUIN .... 4-87
BOITE A VITESSES,
TAMBOUR ET FOURCHETTES
DE SELECTION .......................... 4-96
CHAPITRE 5
PARTIE CYCLE
ROUE AVANT
ET ROUE ARRIERE ..................... 5-1
FREIN AVANT ET FREIN
ARRIERE ...................................... 5-10
FOURCHE AVANT ..................... 5-26
GUIDON ........................................ 5-39
DIRECTION ................................. 5-45
BRAS OSCILLANT ..................... 5-50
AMORTISSEUR ARRIERE ....... 5-58
CAPITOLO 4
MOTORE
SELLA, SERBATOIO
CARBURANTE
E CARENATURA LATERALE ... 4-1
TUBO DI SCARICO
E SILENZIATORE ........................ 4-3
RADIATORE .................................. 4-5
CARBURATORE ........................... 4-8
ALBERI A CAMME .................... 4-21
TESTATA DEL CILINDRO ....... 4-30
VALVOLE
E MOLLE VALVOLE ................. 4-33
CILINDRO E PISTONE .............. 4-42
FRIZIONE ..................................... 4-49
ELEMENTO FILTRANTE
DELL’OLIO, POMPA
DELL’ACQUA E COPERCHIO
CARTER DESTRO ...................... 4-56
BILANCIERE ............................... 4-63
POMPA DELL’OLIO .................. 4-66
ALBERO PEDALE
E ALBERO DEL CAMBIO ......... 4-71
MAGNETE CDI ........................... 4-78
RIMOZIONE DEL MOTORE .... 4-82
CARTER E ALBERO
MOTORE ...................................... 4-87
TRASMISSIONE, CAMMA DEL
CAMBIO E FORCELLA
DEL CAMBIO .............................. 4-96
CAPITOLO 5
PARTE CICLISTICA
RUOTA ANTERIORE E RUOTA
POSTERIORE ................................ 5-1
FRENO ANTERIORE E
POSTERIORE .............................. 5-10
FORCELLA ANTERIORE ......... 5-26
MANUBRIO .................................. 5-39
STERZO ........................................ 5-45
FORCELLONE
OSCILLANTE .............................. 5-50
AMMORTIZZATORE
POSTERIORE .............................. 5-58

GEN
INFO
1 - 1
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1Clutch lever
2Hot starter lever
3Front brake lever
4Throttle grip
5Radiator cap
6Fuel tank cap
7Engine stop switch
8Kickstarter crank
9Fuel tank
0Radiator
ACoolant drain bolt
BRear brake pedal
CValve joint
DFuel cock
ECold starter knob
FDrive chain
GAir filter
HShift pedal
IDipstick
JFront forkNOTE:
The machine you have purchased may differ
slightly from those shown in the following.
Designs and specifications are subject to
change without notice.

GEN
INFO
DESCRIPTION
FAHRZEUGBESCHREIBUNG
DESCRIZIONE
ALLGEMEINE
ANGABEN
FAHRZEUGBESCHREI-
BUNG
1Kupplungshebel
2Heißstarter-Hebel
3Handbremshebel
4Gasdrehgriff
5Kühlerverschlußdeckel
6Kraftstoffankverschluß
7Motorstoppschalter
8Kickstarterhebel
9Kraftstofftank
0Kühler
AKühlmittel-Ablaßschraube
BFußbremshebel
CAuslaufschutzventil
DKraftstoffhahn
EKaltstarterknopf
FAntriebskette
GLuftfilter
HSchalthebel
IMeßstab
JTeleskopgabel
HINWEIS:
Leichte Modell-Abweichungen
möglich.
Änderungen an Design und techni-
schen Daten jederzeit vorbehalten.
RENSEIGNEMENTS
GENERAUX
DESCRIPTION
1Levier d’embrayage
2Levier de démarreur à chaud
3Levier de frein avant
4Poignée des gaz
5Bouchon de radiateur
6Bouchon de réservoir de carburant
7Coupe-circuit du moteur
8Kick
9Réservoir de carburant
0Radiateur
ABoulon de vidange du liquide de
refroidissement
BPédale de frein arrière
CJoint de robinet
DRobinet de carburant
EBouton de démarrage à froid
FChaîne de transmission
GFiltre à air
HSélecteur
IJauge
JFourche avant
N.B.:
Votre machine diffère peut-être par-
tiellement de celle montrée sur ces
photos.
La conception et les caractéristiques
peuvent êtres changées sans préavis.
1 - 1
INFORMAZIONI
GENERALI
DESCRIZIONE
1Leva della frizione
2Leva dell’avviamento a caldo
3Leva del freno anteriore
4Manopola dell’acceleratore
5Tappo del radiatore
6Tappo del serbatoio del carburante
7Interruttore di arresto motore
8Pedivella di avviamento
9Serbatoio del carburante
0Radiatore
ABullone di scarico del refrigerante
BPedale del freno posteriore
CGiunto a valvola
DRubinetto del carburante
EManopola di avviamento a freddo
FCatena di trasmissione
GFiltro aria
HPedale del cambio
IAstina dell’olio
JForcella anteriore
NOTA:
Il veicolo acquistato potrebbe differire
leggermente da quelli illustrati qui di
seguito.
I modelli e le specifiche sono soggetti
a variazioni senza preavviso.
1

GEN
INFO
1 - 7
SPECIAL TOOLS
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the
correct special tool will help prevent damage caused by the use of improper tools or improvised
techniques. The shape and part number used for the special tool differ by country, so two types are
provided. Refer to the list provided to avoid errors when placing an order.
NOTE:
For U.S.A. and Canada, use part number starting with “YM-”, “YU-” or “ACC-”.
For others, use part number starting with “90890-”.
Part number Tool name/How to use Illustration
YU-1135-A, 90890-01135 Crankcase separating tool
These tool is used to remove the crankshaft from
either case.YU-1135-A 90890-01135
YM-1189, 90890-01189 Flywheel puller
This tool is used to remove the flywheel magneto.YM-1189 90890-01189
YU-1235, 90890-01235 Rotor holding tool
This tool is used when loosening or tightening the fly-
wheel magneto securing nut.YU-1235 90890-01235
YU-3097, 90890-01252
YU-1256Dial gauge and stand
Stand
These tools are used to check each part for runout or
bent.YU-3097
YU-125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YU-91044, 90890-04081
YU-90063, 90890-01278Crankshaft installing tool
Crankshaft installing pot
Crankshaft installing bolt
Spacer (crankshaft installer)
Adapter (M12)
These tools are used to install the crankshaft.YU-90050
YU-90063
YU-9104490890-01274
90890-01275
90890-01278
90890-04081
YU-1304, 90890-01304 Piston pin puller set
This tool is used to remove the piston pin.YU-1304 90890-01304
YU-24460-01, 90890-01325
YU-33984, 90890-01352Radiator cap tester
Radiator cap tester adapter
These tools are used for checking the cooling sys-
tem.YU-24460-01
YU-3398490890-01325
90890-01352

GEN
INFO
UTENSILI SPECIALI
UTENSILI SPECIALI
Sono necessari idonei utensili speciali per una messa a punto e un assemblaggio completi e accurati.
L’impiego dell’attrezzo speciale adatto aiuterà a prevenire eventuali danni causati dall’impiego di utensili non
idonei o di tecniche improvvisate. La forma e il numero di pezzo utilizzato per l’attrezzo speciale differiscono
da paese a paese, pertanto ne vengono indicati due tipi. Fare riferimento all’elenco fornito onde evitare errori
quando si effettua un’ordinazione.
NOTA:
Per U.S.A. e Canada, utilizzare il numero di pezzo che comincia con “YM-”, “YU-” o “ACC-”.
Per gli altri, utilizzare il numero di pezzo che comincia con “90890-”.
Numero di pezzo Nome dell’attrezzo/Come utilizzarlo Figura
YU-1135-A, 90890-01135 Utensile per la separazione del carter
Questo attrezzo è utilizzato per disaccoppiare i due
semicarter.YU-1135-A 90890-01135
YM-1189, 90890-01189 Estrattore del volano
Questo attrezzo viene utilizzato per estrarre il magnete del
volano.YM-1189 90890-01189
YU-1235, 90890-01235 Utensile di sostegno per il rotore
Questo attrezzo viene utilizzato quando si svita o si avvita
la vite di fissaggio del magnete del volano.YU-1235 90890-01235
YU-3097, 90890-01252
YU-1256Comparatore e supporto
Supporto
Questi strumenti sono usati per controllare ciascuna parte
per usura o deviazioni.YU-3097
YU-125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YU-91044, 90890-04081
YU-90063, 90890-01278Utensile per il montaggio dell’albero motore
Contenitore per il montaggio dell’albero motore
Bullone per il montaggio dell’albero motore
Distanziatore (dispositivo di installazione dell’albero motore)
Adattatore (M12)
Questi utensili sono utilizzati per installare l’albero motore.YU-90050
YU-90063
YU-9104490890-01274
90890-01275
90890-01278
90890-04081
YU-1304, 90890-01304 Kit estrattore dello spinotto pistone
Questo attrezzo è utilizzato per rimuovere gli spinotti.YU-1304 90890-01304
YU-24460-01, 90890-01325
YU-33984, 90890-01352Tester del tappo radiatore
Adattatore del tester tappo radiatore
Questi utensili sono utilizzati per il controllo del sistema di
raffreddamento.YU-24460-01
YU-3398490890-01325
90890-01352
1 - 7

SPEC

2 - 9
MAINTENANCE SPECIFICATIONS
Lubrication system:
Oil filter type Wire mesh type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Side clearance 0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Housing and rotor clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.0067 in)
Cooling:
Radiator core size
Width 107.8 mm (4.2 in) ----
Height 220 mm (8.7 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure110 kPa (1.1 kg/cm
2

, 15.6 psi)----
Radiator capacity (total) 0.56 L (0.49 Imp qt, 0.59 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

SPEC

2 - 10
MAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S
×
1.0 1 13 1.3 9.4
Camshaft cap M6
×
1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12
×
1.0 1 37 3.7 27
Cylinder head (stud bolt) M6
×
1.0 2 7 0.7 5.1
(stud bolt) M8
×
1.25 1 15 1.5 11
(bolt) M9
×
1.25 4 38 3.8 27
(nut) M6
×
1.0 2 10 1.0 7.2
Cylinder head cover M6
×
1.0 2 10 1.0 7.2
Cylinder M6
×
1.0 1 10 1.0 7.2
Balancer weight M6
×
1.0 2 10 1.0 7.2
Balancer shaft driven gear M14
×
1.0 1 50 5.0 36
Timing chain guide (intake side) M6
×
1.0 2 10 1.0 7.2
Timing chain tensioner M6
×
1.0 2 10 1.0 7.2
Timing chain tensioner cap bolt M6
×
1.0 1 7 0.7 5.1
Impeller M8
×
1.25 1 14 1.4 10
Radiator hose clamp M6
×
1.0 8 2 0.2 1.4
Coolant drain bolt M6
×
1.0 1 10 1.0 7.2
Water pump housing M6
×
1.0 4 10 1.0 7.2
Radiator M6
×
1.0 6 10 1.0 7.2
Radiator guard M6
×
1.0 2 10 1.0 7.2
Radiator pipe M6
×
1.0 1 10 1.0 7.2
Oil pump cover M4
×
0.7 1 2 0.2 1.4
Oil pump M6
×
1.0 3 10 1.0 7.2
Oil filter element drain bolt M6
×
1.0 1 10 1.0 7.2
Oil filter element cover M6
×
1.0 2 10 1.0 7.2
Oil strainer M6
×
1.0 2 10 1.0 7.2
Oil delivery pipe 1 (M10) M10
×
1.25 1 20 2.0 14
(M8) M8
×
1.25 2 18 1.8 13
Oil hose M6
×
1.0 2 10 1.0 7.2
Oil hose clamp—2 2 0.2 1.4
Oil strainer and frame M14
×
1.5 1 70 7.0 50
Carburetor joint clamp M4
×
0.7 2 3 0.3 2.2
Air filter joint clamp M6
× 1.0 1 3 0.3 2.2
Throttle cable cover M5 × 0.8 2 4 0.4 2.9
Hot starter plunger M12 × 1.0 1 2 0.2 1.4
Air filter case M6 × 1.0 2 8 0.8 5.8
Air filter joint and air filter case M5 × 0.8 1 4 0.4 2.9
Air filter element M6 × 1.0 1 2 0.2 1.4
Exhaust pipe (nut) M8 × 1.25 1 13 1.3 9.4
(bolt) M8 × 1.25 1 24 2.4 17
Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2