2002 YAMAHA WR 250F diagram

EC083000
MANUAL FORMAT
All of the procedures in this manual are organized in a sequential, step-by-step format. The informa-
tion has been complied to provide the mechanic with an easy to read, handy reference that contains
comprehensive explanations of all disassembly, repair, assembly, and inspection operations.
In this revised format, the condition of a faulty component will precede an arrow symbol and the
course of action required will follow the symbol, e.g.,

Bearings
Pitting/damage
→
Replace.
EC084002
HOW TO READ DESCRIPTIONS
To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
1. An easy-to-see exploded diagram
1
is provided for removal and disassembly jobs.
2. Numbers
2
are given in the order of the jobs in the exploded diagram. A number that is
enclosed by a circle indicates a disassembly step.
3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol
marks
3
. The meanings of the symbol marks are given on the next page.
4. A job instruction chart
4
accompanies the exploded diagram, providing the order of jobs,
names of parts, notes in jobs, etc.
5. Extent of removal
5
is provided in the job instruction chart to save the trouble of an unneces-
sary removal job.
6. For jobs requiring more information, the step-by-step format supplements
6
are given in addi-
tion to the exploded diagram and job instruction chart.

AUFBAU
Diese Anleitung wurde zusammen-
gestellt, um dem Benutzer ein leicht
verständliches Nachschlagewerk in
die Hand zu geben, in dem alle dar-
gestellten Arbeitsvorgänge (Ein- und
Ausbau, Zerlegung und Zusammen-
bau, Prüfung und Reparatur) detail-
liert und in der entsprechenden
Reihenfolge beschrieben sind.
Je nach Zustand eines fehlerhaften
Bauteils weist ein Pfeilsymbol auf die
erforderliche Maßnahme hin. Bei-
spiel:

Lager
Pitting/Beschädigung
→
Erneuern.
LESEN DER BESCHREIBUNGEN
Um bei der Identifikation der Teile zu
helfen und die Arbeitsschritte zu ver-
deutlichen, sind Explosionsdia-
gramme am Beginn jedes Ausbau-
und Demontageabschnittes darge-
stellt.
1. Für die Ausbau- und Demonta-
gearbeiten ist meistens ein über-
sichtliches Explosionsdiagramm
1
dargestellt.
2. Die Nummern
2
in dem Explosi-
onsdiagramm sind in der Rei-
henfolge der Arbeiten
aufgeführt. Eine in einen Kreis
eingeschriebene Nummer
bezeichnet einen Demontage-
schritt.
3. Eine Erläuterung der Arbeiten
und Hinweise ist durch ablese-
freundliche Symbolmarkierun-
gen
3
gegeben. Die
Bedeutungen der Symbolmar-
kierungen sind auf der nächsten
Seite aufgeführt.
4. Eine Arbeitsanweisungstabelle
4
begleitet das Explosionsdia-
gramm und gibt die Arbeitsrei-
henfolge, Bezeichnung der
Teile, Hinweise zu den Arbeiten
usw. an.
5. Der Umfang des Ausbaus
5
ist
in der Arbeitsanweisungstabelle
aufgeführt, um nicht erforderli-
che Ausbauarbeiten zu vermei-
den.
6. Für Arbeiten, für die weitere
Informationen benötigt werden,
sind schrittweise Ergänzungen
6
zusätzlich zu dem Explosi-
onsdiagramm und der Arbeitsan-
weisungstabelle aufgeführt.
FORMAT DU MANUEL
Dans ce manuel, toutes les procédures
sont décrites pas à pas. Les informations
ont été condensées pour fournir au méca-
nicien un guide pratique et facile à lire,
contenant des explications claires pour
toutes les procédures de démontage,
réparation, remontage et vérification.
Dans ce nouveau format, l’état d’un
composant défectueux est suivi d’une
flèche qui indique les mesures à prendre.
Exemple:

Roulements
Piqûres/endommagement
→
Rempla-
cer.
COMMENT LIRE LES DESCRIP-
TIONS
Chaque section détaillant des étapes de
démontage ou de remontage est précédée
de vues en éclaté qui permettent de clari-
fier ces opérations.
1. Exemple de vue en éclaté
1
clari-
fiant les opérations de démontage et
de remontage.
2. Sur les vues en éclaté, les pièces
sont numérotées
2
dans l’ordre des
opérations à effectuer. Un chiffre
entouré d’un cercle correspond à
une étape de démontage.
3. Les vues en éclaté portent égale-
ment des symboles
3
qui rappel-
lent des points importants à ne pas
oublier. La signification de ces sym-
boles est expliquée à la page sui-
vante.
4. Les vues en éclaté sont suivies d’un
tableau
4
fournissant l’ordre des
opérations, le nom des pièces, des
remarques, etc.
5. Pour éviter la dépose superflue de
pièces, l’étendue de la dépose
5
est
indiquée dans le tableau de descrip-
tion du travail.
6. Pour les travaux qui demandent des
explications supplémentaires, la vue
en éclaté et le tableau sont suivis
d’une description détaillée
6
des
opérations.
STRUTTURA DEL
MANUALE
Tutte le procedure di questo manuale
sono organizzate in sequenze passo a
passo. Le informazioni sono state redatte
in modo tale da fornire al meccanico un
riferimento comodo e di agevole lettura
che comprenda, al contempo, spiega-
zioni complete relative alle operazioni di
smontaggio, riparazione, montaggio ed
ispezione.
In questo nuovo formato, la condizione
di un componente non funzionante pre-
cede una freccia e l’azione richiesta
segue il simbolo., ad es.:

Cuscinetti
Puntinatura/danno
→
Sostituire.
COME LEGGERE LE DESCRI-
ZIONI
Allo scopo di agevolare l’identificazione
dei pezzi e di chiarire le fasi delle varie
procedure, sono state inserite rappresen-
tazioni esplose all’inizio di ciascun para-
grafo dedicato alla rimozione e allo
smontaggio.
1. Una rappresentazione esplosa di
immediata comprensione
1
viene
fornita per agevolare le operazioni
di rimozione e smontaggio.
2. I numeri
2
sono indicati nella rap-
presentazione esplosa secondo la
sequenza di lavoro. Un numero rac-
chiuso in un cerchietto indica una
fase di un’operazione di smontag-
gio.
3. Una spiegazione delle operazioni e
delle note viene illustrata in maniera
chiara dall’impiego di riferimenti
simbolici
3
. Il significato dei riferi-
menti simbolici viene fornito alla
pagina seguente.
4. Uno schema di istruzioni di lavoro
4
unitamente alla rappresenta-
zione esplosa, fornisce la sequenza
dei lavori, i nomi dei pezzi, le note
relative ai lavori, ecc.
5. L’indicazione relativa alla portata
dell’intervento di rimozione
5
viene fornita nello schema di istru-
zioni per evitare operazioni di rimo-
zione non necessaire.
6. Per quegli interventi che richiedono
maggiori informazioni, vengono
forniti supplementi in formato passo
a passo
6
oltre alla rappresenta-
zione esplosa e allo schema di istru-
zioni.

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols
1
to
7
are designed as
thumb tabs to indicate the chapter’s number
and content.
1
General information
2
Specifications
3
Regular inspection and adjustments
4
Engine
5
Chassis
6
Electrical
7
Tuning
Illustrated symbols
8
to
D
are used to identify
the specifications appearing in the text.
8
With engine mounted
9
Special tool
0
Filling fluid
A
Lubricant
B
Tightening
C
Specified value, Service limit
D
Resistance (
Ω
), Voltage (V), Electric current (A)
Illustrated symbols
E
to
H
in the exploded
diagrams indicate grade of lubricant and loca-
tion of lubrication point.
E
Apply engine oil
F
Apply molybdenum disulfide oil
G
Apply lightweight lithium-soap base grease
H
Apply molybdenum disulfide grease
Illustrated symbols
I
to
J
in the exploded
diagrams indicate where to apply a locking
agent and where to install new parts.
IApply locking agent (LOCTITE®)
JUse new one 12
34
56
78
90
AB
CD
EF
GH
IJ
GEN
INFOSPEC
INSP
ADJENG
CHAS–+ELEC
TUN
T R..
EM
BM

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION
.......................................... 1-1
MACHINE IDENTIFICATION
.................... 1-2
IMPORTANT INFORMATION
................... 1-3
CHECKING OF CONNECTION
................ 1-6
SPECIAL TOOLS
...................................... 1-7
CONTROL FUNCTIONS
......................... 1-10
FUEL
....................................................... 1-14
STARTING AND BREAK-IN
................... 1-15
TORQUE-CHECK POINTS
..................... 1-19
CLEANING AND STORAGE
.................. 1-20
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
.................. 2-1
MAINTENANCE SPECIFICATIONS
......... 2-4
GENERAL TORQUE
SPECIFICATIONS
.................................. 2-18
DEFINITION OF UNITS
.......................... 2-18
CABLE ROUTING DIAGRAM
................ 2-19
CHAPTER 3
REGULAR INSPECTION AND
ADJUSTMENTS
MAINTENANCE INTERVALS
................... 3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
............................... 3-4
ENGINE
..................................................... 3-5
CHASSIS
................................................. 3-26
ELECTRICAL
.......................................... 3-47

CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM
.......................... 6-1
MAP-CONTROLLED CDI UNIT
................ 6-2
IGNITION SYSTEM
................................... 6-3
THROTTLE POSITION SENSOR
SYSTEM
.................................................... 6-7
LIGHTING SYSTEM
................................ 6-12
CHAPTER 7
TUNING
ENGINE
..................................................... 7-1
CHASSIS
................................................. 7-12

2 - 19
SPEC

CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Hose guide
2
Brake hose
3
Voltage regulator
4
Light switch lead
5
Fuel tank breather hose
6
Engine stop switch lead
7
Clamp
8
Oil tank breather hose
9
Sub-wire harness
0
Taillight lead
A
Throttle position sensor lead
B
Neutral switch lead
C
Oil hose
D
Cylinder head breather hose
E
CDI magneto lead
F
Clutch cable
G
Cable guide
H
Carburetor breather hose
I
Carburetor overflow hose
J
Coolant reservoir breather hose
K
Decompression cable
L
Ground lead
M
Ignition coil lead
N
CDI unit lead
O
Voltage regulator lead
Å
Pass the fuel tank breather hose
behind handlebar, then insert it
into the steering stem hole.
ı
Pass the decompression cable,
engine stop switch lead and light
switch lead under where the oil
hose is attached.
Ç
Pass the voltage regulator lead,
engine stop switch lead and light
switch lead over the radiator
hose.
Î
Fasten the engine stop switch
lead, light switch lead and igni-
tion coil lead of the sub-wire har-
ness.
‰
Fasten the sub-wire harness
and engine stop switch lead.
Ï
Pass the cylinder head breather
hose along the right side of the
oil tank breather hose.
Ì
Fasten the sub-wire harness
and light switch lead in front of
the upper engine brackets.
Ó
Fasten the sub-wire harness.
È
Pass the sub-wire harness
between the upper engine
brackets.
Ô
Fasten the sub-wire harness.

Fasten the throttle position sen-
sor lead.

2 - 20
SPEC

CABLE ROUTING DIAGRAM
Ò
Make sure that the throttle
position sensor lead coupler
does not go outside the chas-
sis.
˜
Pass the carburetor breather
hoses and overflow hose
between the connecting rod
and cross tube (frame).
ˆ
Fasten the neutral switch lead
on the oil hose with a plastic
locking tie and cut off the tie
end.
Ø
Pass the cylinder head
breather hose through the hose
guide.
∏
Pass the clutch cable through
the cable guide.
Œ
Fasten the neutral switch lead
and CDI magneto lead.
Â
Pass the clutch cable along the
inner side of the cylinder head
breather hose.
Í
Pass the cylinder head
breather hose along the inner
side of the radiator hose.
Ê
Pass the clutch cable in front of
the radiator mounting boss.
Ë
Fit the brake hose into the
guides on the protector.
◊
Pass the neutral switch lead
and CDI magneto lead through
the cable guide.
„
Fasten the ground lead
together with the ignition coil
lead.
Ù
Do not allow the light switch
lead to slacken between the
two clamps.
Á
Pass the decompression cable
along the right side of the cylin-
der head breather hose.
Û
Pass the clutch cable through
the cable guides.
Pass the carburetor breather
hoses, overflow hose and
coolant reservoir breather
hose so that all there hoses
do not contact the rear shock
absorber.
Position each lead at the
lower left of the main tube
(frame).
AA
AB

2 - 21
SPEC

1
Coolant reservoir breather hose
2
Radiator breather hose
3Ignition coil
4CDI unit
5CDI unit band
6Throttle cable (return)
7Throttle cable (pull)
8Cable guide
9CDI unit lead
0Spark plug lead
ACDI unit stayÅFasten the coolant reservoir breather hose and
carburetor breather hoses together.
ıPass the throttle cables along inner side of the
spark plug lead.
ÇPass the CDI unit lead between the radiator hose
and radiator mounting boss.
ÎPass the throttle cables through the cable guides.
‰Insert the CDI unit band over the CDI unit stay
(frame) as far as possible.
CABLE ROUTING DIAGRAM