2001 YAMAHA WR 250F stop start

3 - 5
INSP
ADJ
EC350000
ENGINE
EC351011
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap 1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
1. Place the machine on a level place, and
hold it in an upright position.
2. Inspect:
lCoolant level
Coolant level should be between the
maximum a and minimum b marks.
Coolant level is below the “LOW” level
line ® Add soft water (tap water) up to
the proper level.
3. Start the engine and let it warm up for
several minutes.
4. Turn off the engine and check the coolant
level again.
NOTE:
Before checking the coolant level, wait a few
minutes until the coolant settles.
LOWFULLCOOLANT
a
b
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
ENGINE/COOLANT LEVEL INSPECTION/
COOLANT REPLACEMENT

3 - 12
INSP
ADJ
AIR FILTER CLEANING
2. Adjust:
lDecompression lever free play
Adjustment steps:
lLoosen the locknut 1.
lTurn the adjuster 2 in or out until the
adjustment is suitable.
lTighten the locknut.
CAUTION:
After the adjustment, start the engine
and make sure that the engine does not
stop when the handlebar is turned fully
both ways. If the decompression cable is
too tense, the engine will stop by the
decompression system.
AIR FILTER CLEANING
NOTE:
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage.
CAUTION:
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage.
1. Remove:
lSeat
2. Disconnect:
lTaillight lead connectors 1
3. Remove:
lAir filter case cover 2
4. Remove:
lFitting bolt 1
lWasher 2
lAir filter element 3
lAir filter guide 4

INSP
ADJ
CHANGEMENT DE L’HUILE DE MOTEUR
MOTORÖL WECHSELN
SOSTITUZIONE DELL’OLIO MOTORE
MOTORÖL WECHSELN
1. Den Motor starten, mehrere
Minuten warmlaufen lassen,
und dann ausschalten und
fünf Minuten warten.
2. Die Maschine auf ebenem Ort
abstellen und auf dem Motor
aufbocken.
3. Einen geeigneten Behälter un-
ter den Motor stellen.
4. Demontieren:
lÖltankdeckel 1
lRahmen des Ölablaufstop-
fens 2
lKurbelwellen-Ölablaufstop-
fen 3
lÖlfilterelement-Ablaufstop-
fen 4
Das Kurbelgehäuse und den
Öltank (Rahmen) leerlaufen
lassen.
5. Demontieren:
lUnterer Motorbügel
lÖlschlauchklammer 1
lSteckschraube (Öl-
schlauch) 2
lÖlschlauch 3
lÖlsieb (Rahmen) 4
6. Kontrollieren:
lÖlsieb (Rahmen)
lVerstopft ® Ausblasen. CHANGEMENT DE L’HUILE DE
MOTEUR
1. Mettre le moteur en marche, le
faire chauffer pendant quelques
minutes, puis le couper et atten-
dre cinq minutes.
2. Placer le véhicule sur un plan
horizontal et le dresser à la verti-
cale en plaçant un support adé-
quat sous le moteur.
3. Déposer un récipient adéquat
sous le moteur.
4. Déposer:
lBouchon du réservoir d’huile
1
lBoulon de vidange d’huile au
cadre 2
lBoulon de vidange d’huile de
carter 3
lBoulon de vidange d’élément
de filtre à huile 4
Vidanger l’huile du carter
moteur et du réservoir d’huile
(cadre).
5. Déposer:
lSupport inférieur de moteur
lBride de durit d’huile 1
lBoulon (durit d’huile) 2
lDurit d’huile 3
lCrépine d’huile (cadre) 4
6. Vérifier:
lCrépine d’huile (cadre)
lBouché ® Passer à l’air com-
primé.SOSTITUZIONE DELL’OLIO
MOTORE
1. Avviare il motore, riscaldarlo per
alcuni minuti e quindi spegnerlo
ed attendere cinque minuti.
2. Posizionare il veicolo su una
superficie piana e tenerlo in posi-
zione eretta utilizzando il caval-
letto apposito posto sotto al
motore.
3. Posizionare un contenitore ido-
neo sotto al motore.
4. Rimuovere:
lTappo del serbatoio dell’olio
1
lBullone di scarico dell’olio del
telaio 2
lBullone di scarico dell’olio del
carter 3
lBullone di scarico elemento fil-
trante 4
Scaricare l’olio dal carter e dal
serbatoio dell’olio (telaio).
5. Rimuovere:
lStaffa motore inferiore
lFascetta fermatubo dell’olio 1
lBullone (tubo flessibile
dell’olio) 2
lTubo flessibile dell’olio 3
lFiltro dell’olio (telaio) 4
6. Ispezionare:
lFiltro dell’olio (telaio)
lIntasato ® Pulire con aria.
3 - 16

3 - 19
INSP
ADJ
ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it
up.
2. Attach:
lInductive tachometer
To spark plug lead.
3. Adjust:
lEngine idling speed
Adjustment steps:
lAdjust the pilot screw.
Refer to “PILOT SCREW ADJUSTMENT”
section.
lTurn the throttle stop screw 1 until the
engine runs at the lowest possible speed.
To increase idle speed ®
Turn the throttle stop screw 1 in a.
To decrease idle speed ®
Turn the throttle stop screw 1 out b.
Inductive tachometer:
YU-08036-B
Engine tachometer:
90890-03113
Engine idling speed:
1,700 ~ 1,900 r/min
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
NOTE:
lThe valve clearance should be adjusted
when the engine is cool to the touch.
lThe piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
lSeat
lFuel tank
Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section in the CHAP-
TER 4.
2. Drain:
lCoolant
Refer to “COOLANT REPLACEMENT”
section.
ENGINE IDLING SPEED ADJUSTMENT/
VALVE CLEARANCE INSPECTION AND ADJUSTMENT

4 - 16
ENGCARBURETOR
10. Install:
lStarter jet 1
lPilot jet 2
lSpacer 3
lNeedle jet 4
lMain jet 5
11. Install:
lValve seat
lScrew (valve seat) 1
lNeedle valve 2
lFloat 3
lFloat pin 4
NOTE:
lAfter installing the needle valve to the float,
install them to the carburetor.
lCheck the float for smooth movement.
12. Install:
lPilot screw 1
lSpring 2
lWasher 3
lO-ring 4
Note the following installation points:
lTurn in the pilot screw until it is lightly
seated.
lTurn out the pilot screw by the number of
turns recorded before removing.
Pilot screw:
1-3/4 turns out (example)
13. Install:
lO-ring
lLeak jet 1
lFloat chamber 2
lBolt (float chamber) 3
lCable holder (throttle stop screw cable)
4
lHose holder (carburetor breather hose)
5

6 - 4
–+ELEC

IGNITION SYSTEM
SPARK GAP TEST
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester
1
(ignition checker
2
) as shown.
l
Spark plug cap
3

l
Spark plug
4


For USA and CDN
õ
Except for USA and CDN
3. Kick the kickstarter crank.
4. Check the ignition spark gap.
5. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only)
Minimum spark gap:
6.0 mm (0.24 in)

õ

EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
l
Couplers and leads connection
Rust/dust/looseness/short-circuit
®

Repair or replace.
ENGINE STOP SWITCH INSPECTION
1. Inspect:
l
Engine stop switch conduct
No continuous while being pushed
®
Replace.
Continuous while being freed
®
Replace.
Tester (+) lead
®
Black/White lead
1

Tester (–) lead
®
Black lead
2

B/W
1
B
2
Tester selec-
tor position
PUSH IN
W

´
1
FREE

–+ELEC
SYSTEME D’ALLUMAGE
ZÜNDANLAGE
IMPIANTO DI ACCENSIONE
ZÜNDFUNKENSTRECKE KON-
TROLLIEREN
1. Den Zündkerzenstecker von
der Zündkerze abziehen.
2. Den Zündfunkenstreckente-
ster 1 (bzw. 2) wie abgebil-
det anschließen.
lZündkerzenstecker 3
lZündkerze 4
Nur USA und CDN
õNicht USA und CDN
3.Den Motor mit dem Kick-
starter durchdrehen
.
4. Die Zündfunkenstrecke kon-
trollieren.
5. Den Motor anlassen und die
Zündfunkenstrecke vergrö-
ßern, bis es zu Fehlzündun-
gen kommt (nur USA und
CDN).
Min. Zündfunkenstrecke
6,0 mm
STECKVERBINDER- UND KABEL-
ANSCHLÜSSE KONTROLLIEREN
1. Kontrollieren:
lSteckverbinder- und Kabel-
anschlüsse
Rost/Staub/Lockerheit/Kurz-
schluß ® Instand setzen
oder erneuern.
MOTORSTOPPSCHALTER
KONTROLLIEREN
1. Kontrollieren:
lMotorstoppschalter
(auf Durchgang)
Kein Durchgang bei gedrücktem
Schalter ® Erneuern.
Durchgang bei freigelassenem
Schalter ® Erneuern. Meßkabel (+) ®
schwarz/weiß 1
Meßkabel (–) ® schwarz 2
B/W
1 B
2 Meßge-
rät-
Einstel-
GE-
DRÜCKT
W ´ 1
FREI
TEST DE LA LONGUEUR D’ETIN-
CELLE D’ALLUMAGE
1. Déconnecter le capuchon de bou-
gie de la bougie.
2. Connecter le testeur dynamique
d’étincelle 1 (testeur d’allu-
mage 2) comme indiqué.
lCapuchon de bougie 3
lBougie 4
Pour les USA et le CDN
õExcepté pour les USA et le CDN
3. Actionner le kick.
4. Contrôler la longueur d’étincelle
d’allumage.
5. Démarrer le moteur et augmenter
la longueur d’étincelle jusqu’à ce
qu’un raté se produise. (unique-
ment USA et CDN)
Longueur d’étincelle mini-
mum:
6,0 mm (0,24 in)
CONTROLE DES CONNEXIONS
DE COUPLEURS ET FILS
1. Contrôler:
lConnexion de coupleurs et fils
Rouille/poussière/jeu/court-cir-
cuit ® Réparer ou Remplacer.
CONTROLE DU COUPE-CIRCUIT
DU MOTEUR
1. Vérifier:
lContinuité du coupe-circuit du
moteur
Pas de continuité lorsqu’enfoncé ®
Remplacer.
Continuité lorsque relâché ® Rempla-
cer.Fil (+) de multimètre ®
Fil noir/blanc 1
Fil (–) de multimètre ®
Fil noir 2
B/W
1B
2Position de
sélecteur
du multi-
mètre
EN-
FONCE
W ´ 1
RE-
LACHE
6 - 4
Test della distanza tra gli elettrodi
1. Staccare il cappuccio della can-
dela.
2. Collegare il tester della dinami-
cità della scintilla 1 (tester
dell’accensione 2) come illu-
strato.
lCappuccio della candela 3
lCandela 4
Per USA e CDN
õTranne USA e CDN
3. Agire sulla pedivella di avvia-
mento.
4. Controllare la distanza tra gli
elettrodi.
5. Avviare il motore ed aumentare
la distanza tra gli elettrodi fino a
che non si verifica uno scatto a
vuoto. (Solo per USA e CDN)
Distanza minima tra gli
elettrodi:
6,0 mm (0,24 in)
ISPEZIONE DEI COLLEGAMENTI
DEGLI ACCOPPIATORI E DEI
CAVI
1. Controllare:
lCollegamento degli accoppia-
tori e dei cavi
Ruggine/polvere/allentamento/
cortocircuito ® Riparare o
sostituire.
ISPEZIONE DELL’INTERRUT-
TORE DI ARRESTO DEL MOTORE
1. Ispezionare:
lConduzione interruttore di
arresto motore
Assenza di continuità se premuto ®
Sostituire.
Continuità se rilasciato® Sostituire. Conduttore (+) del tester ®
Conduttore nero/bianco 1
Conduttore (–) del tester ®
Conduttore nero 2
B/W
1B
2Posizione
selettore
tester
PRE-
MUTO
W ´ 1
RILA-
SCIATO

7 - 2
TUN
CAUTION:

l
The carburetor is extremely sensitive to
foreign matter (dirt, sand, water, etc.).
During installation, do not allow foreign
matter to get into the carburetor.
l
Always handle the carburetor and its
components carefully. Even slight
scratches, bends or damage to carbure-
tor parts may prevent the carburetor from
functioning correctly. Carefully perform
all servicing with the appropriate tools
and without applying excessive force.
l
When the engine is stopped or when
riding at no load, do not open and close
the throttle unnecessarily. Otherwise, too
much fuel may be discharged, starting
may become difficult or the engine may
not run well.
l
After installing the carburetor, check that
the throttle operates correctly and opens
and closes smoothly.
Atmospheric conditions and carburetor
settings
The air density (i.e., concentration of oxygen
in the air) determines the richness or lean-
ness of the air/fuel mixture. Therefore, refer
to the above table for mixture settings.
That is:
l
Higher temperature expands the air with its
resultant reduced density.
l
Higher humidity reduces the amount of oxy-
gen in the air by so much of the water vapor
in the same air.
l
Lower atmospheric pressure (at a high alti-
tude) reduces the density of the air.
Air temp. HumidityAir
pressure
(altitude)Mixture Setting
High High Low (high) Richer Leaner
Low Low High (low) Leaner Richer
SETTING