lock YAMAHA YZ250F 2001 Manuale duso (in Italian)

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 (
W
), 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

1 - 4
GEN
INFO

IMPORTANT INFORMATION
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.
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should
be replaced when an engine is over-
hauled. 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
1
and 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)
1
and oil seal(s)
2
with their manufacturer’s marks or num-
bers 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 bearings liberally when
installing.
CAUTION:

Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.

1 - 19
GEN
INFO
CLEANING AND STORAGE
EC1B0000
CLEANING AND STORAGE
EC1B1000
CLEANING
Frequent cleaning of your machine will
enhance its appearance, maintain good over-
all performance, and extend the life of many
components.
1. Before washing the machine, block off
the end of the exhaust pipe to prevent
water from entering. A plastic bag
secured with a rubber band may be used
for this purpose.
2. If the engine is excessively greasy, apply
some degreaser to it with a paint brush.
Do not apply degreaser to the chain,
sprockets, or wheel axles.
3. Rinse the dirt and degreaser off with a
garden hose; use only enough pressure
to do the job.
CAUTION:
Excessive hose pressure may cause water
seepage and contamination of wheel bear-
ings, front forks, brakes and transmission
seals. Many expensive repair bills have
resulted from improper high pressure
detergent applications such as those avail-
able in coin-operated car washers.
4. After the majority of the dirt has been
hosed off, wash all surfaces with warm
water and a mild detergent. Use an old
toothbrush to clean hard-to-reach places.
5. Rinse the machine off immediately with
clean water, and dry all surfaces with a
soft towel or cloth.
6. Immediately after washing, remove
excess water from the chain with a paper
towel and lubricate the chain to prevent
rust.
7. Clean the seat with a vinyl upholstery
cleaner to keep the cover pliable and
glossy.
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid com-
bination cleaner-waxes, as they may con-
tain abrasives.
9. After completing the above, start the
engine and allow it to idle for several min-
utes.

1 - 20
GEN
INFO
CLEANING AND STORAGE
EC1B2001
STORAGE
If your machine is to be stored for 60 days or
more, some preventive measures must be
taken to avoid deterioration. After cleaning the
machine thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and the
carburetor float bowl.
2. Remove the spark plug, pour a table-
spoon of SAE 10W-30 motor oil in the
spark plug hole, and reinstall the plug.
With the engine stop switch pushed in,
kick the engine over several times to coat
the cylinder walls with oil.
3. Remove the drive chain, clean it thor-
oughly with solvent, and lubricate it.
Reinstall the chain or store it in a plastic
bag tied to the frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels off
the ground.
6. Tie a plastic bag over the exhaust pipe
outlet to prevent moisture from entering.
7. If the machine is to be stored in a humid
or salt-air environment, coat all exposed
metal surfaces with a film of light oil. Do
not apply oil to rubber parts or the seat
cover.
NOTE:
Make any necessary repairs before the
machine is stored.

SPEC

2 - 6
MAINTENANCE SPECIFICATIONS
Stem runout limit ---- 0.01 mm
(0.0004 in)
Valve seat width IN 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
EX 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
Valve spring:
Free length IN 37.81 mm (1.49 in) 35.9 mm
(1.41 in)
EX 37.54 mm (1.48 in) 35.7 mm
(1.41 in)
Set length (valve closed) IN 29.13 mm (1.15 in) ----
EX 29.30 mm (1.15 in) ----
Compressed pressure
(installed) IN 99 ~ 114 N
(10.1 ~ 11.6 kg, 22.27 ~ 25.57 lb)----
EX 126 ~ 144 N
(12.9 ~ 14.7 kg, 28.44 ~ 32.41 lb)----
Tilt limit IN ----2.5˚/ 1.7 mm
(2.5˚/0.067 in)
EX ----2.5˚/1.6 mm
(2.5˚/0.063 in)
Direction of winding
(top view) IN Clockwise ----
EX Clockwise ----
Piston:
Piston to cylinder clearance 0.040 ~ 0.065 mm
(0.0016 ~ 0.0026 in)0.1 mm
(0.004 in)
Piston size “D” 76.955 ~ 76.970 mm
(3.0297 ~ 3.0303 in)----
Measuring point “H” 8 mm (0.31 in) ----
Piston off-set 0.5 mm (0.020 in)/IN-side ----Item Standard Limit
*
H
D

SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the steering
nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 7 Nm (0.7 m • kg, 5.1 ft • lb).Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Upper bracket and outer tube M8 ´ 1.25 4 23 2.3 17
Lower bracket and outer tube M8 ´ 1.25 4 20 2.0 14
Upper bracket and steering stem M24 ´ 1.0 1 145 14.5 105
Handlebar holder and upper bracket M8 ´ 1.25 4 28 2.8 20
Steering stem and steering ring nut M28 ´ 1.0 1 Refer to NOTE.
Front fork and front fork cap bolt M48 ´ 1.0 2 30 3.0 22
Front fork and base valve M30 ´ 1.0 2 55 5.5 40
Front fork cap bolt and damper rod M12 ´ 1.25 2 29 2.9 21
Front fork bleed screw and front fork cap bolt M5 ´ 0.8 2 1 0.1 0.7
Front fork and front fork protector M6 ´ 1.0 6 10 1.0 7.2
Front fork and brake hose guide M5 ´ 0.8 1 4 0.4 2.2
Front fork and brake hose holder M6 ´ 1.0 2 10 1.0 7.2
Front fork and brake hose cover (M8) M8 ´ 1.25 1 16 1.6 11
(M6) M6 ´ 1.0 1 7 0.7 5.1
Throttle grip cap M5 ´ 0.8 2 4 0.4 2.2
Front brake master cylinder M6 ´ 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 ´ 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 ´ 1.0 1 6 0.6 4.3
Brake lever position locknut M6 ´ 1.0 1 5 0.5 3.6
Clutch lever holder M5 ´ 0.8 2 4 0.4 2.2
Clutch lever mounting bolt M6 ´ 1.0 1 2 0.2 1.4
Decompression lever holder M5 ´ 0.8 2 4 0.4 2.2
Front brake master cylinder cap M4 ´ 0.7 2 2 0.2 1.4
Front brake hose union bolt M10 ´ 1.25 2 30 3.0 22
Front brake caliper M8 ´ 1.25 2 23 2.3 17
Pad pin plug M10 ´ 1.0 2 3 0.3 2.2
Front brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Rear brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Brake caliper and bleed screw M8 ´ 1.25 2 6 0.6 4.3
Front wheel axle and axle nut M16 ´ 1.5 1 105 10.5 75
Front wheel axle holder M8 ´ 1.25 4 23 2.3 17
Front brake disc M6 ´ 1.0 6 12 1.2 8.7
Rear brake disc M6 ´ 1.0 6 14 1.4 10
Brake pedal M8 ´ 1.25 1 26 2.6 19
Rear brake master cylinder M6 ´ 1.0 2 10 1.0 7.2
Rear brake reservoir tank M6 ´ 1.0 1 10 1.0 7.2
Rear brake reservoir tank cap M4 ´ 0.7 2 2 0.2 1.4
Rear brake hose union bolt M10 ´ 1.25 2 30 3.0 2.2
Rear wheel axle and axle nut M20 ´ 1.5 1 125 12.5 90

3 - 5
INSP
ADJ
EC350000
ENGINE
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. Remove:
lRadiator cap
3. Check:
lCoolant level a
Coolant level low ® Add coolant.
1Radiator
1a
ENGINE/COOLANT LEVEL INSPECTION

3 - 9
INSP
ADJ
CLUTCH ADJUSTMENT
NOTE:
lDo not apply pressure more than specified
pressure.
lRadiator should be filled fully.
4. Inspect:
lPressure
Impossible to maintain the specified
pressure for 10 seconds ® Repair.
lRadiator 1
lRadiator hose joint 2
Coolant leakage ® Repair or replace.
lRadiator hose 3
Swelling ® Replace.
CLUTCH ADJUSTMENT
1. Check:
lClutch lever free play a
Out of specification ® Adjust.
Clutch lever free play a:
2 ~ 4 mm (0.08 ~ 0.16 in)
2. Adjust:
lClutch lever free play
NOTE:
lMake minute adjustment on the lever side
using the adjuster 2.
lAfter adjustment, check proper operation of
clutch lever. Clutch lever free play adjustment steps:
lLoosen the locknuts 1.
lAdjust the free play by changing their
tightening position.
lTighten the locknuts.

INSP
ADJ
REGLAGE DE L’EMBRAYAGE
KUPPLUNG EINSTELLEN
REGOLAZIONE FRIZIONE
HINWEIS:
lDen vorgeschriebenen Druck nicht
Überschreiten.
lDer Kühler muß bis zum Rand ge-
füllt sein.
4. Kontrollieren:
lDruck
Druckverlust innerhalb 10
Sekunden ® Instand set-
zen.
lKühler 1
lSchlauchanschlüsse 2
Undichtigkeit ® Instand set-
zen oder erneuern.
lKühlerschläuche 3
Quellung ® Erneuern.
KUPPLUNG EINSTELLEN
1. Kontrollieren:
lKupplungszugspiel a
Unvorschriftsmäßig ® Ein-
stellen.
Kupplungszugspiel am
Hebeldrehpunkt a
2–4 mm
2. Einstellen:
lKupplungszugspiel
HINWEIS:
lDas Kupplungszugspiel mit der vor
dem Hebel liegenden Einstell-
schraube 2 feineinstellen.
lNach der Einstellung des Seilzug-
spiels die Funktion des Kupplungs-
hebels prüfen. Arbeitsschritte
lSicherungsmutter 1 lockern.
lAnzugsposition verdrehen, bis
das vorgeschriebene Spiel er-
reicht ist
lSicherungsmutter festziehen.
N.B.:
lNe pas appliquer de pression supé-
rieure à la pression spécifiée.
lLe radiateur doit être entièrement rem-
pli.
4. Vérifier:
lPression
Impossible de maintenir la
pression spécifiée pendant 10
secondes ® Réparer.
lRadiateur 1
lRaccord des tuyaux du radia-
teur 2
Fuites du liquide de refroidis-
sement ® Réparer ou changer.
lTuyaux du radiateur 3
Gonflement ® Remplacer.
REGLAGE DE L’EMBRAYAGE
1. Contrôler:
lJeu du levier d’embrayage a
Hors spécification ® Régler.
Jeu du levier d’embrayage
a:
2 à 4 mm (0,08 à 0,16 in)
2. Régler:
lJeu de levier d’embrayage
N.B.:
lFaire un réglage plus fin du côté du
levier à l’aide du dispositif de réglage
2.
lAprès le réglage, contrôler de bon
fonctionnement du levier d’embrayage. Etapes de réglage du jeu du levier
d’embrayage:
lDesserrer les contre-écrous 1.
lRégler le jeu en modifiant leur ser-
rage.
lSerrer les contre-écrous.
3 - 9
NOTA:
lNon applicare pressione superiore a
quella specificata.
lRiempire completamente il radiatore.
4. Ispezionare:
lPressione
Impossibile mantenere la pres-
sione specificata per 10
secondi ® Riparare.
lRadiatore 1
lGiunto tubo flessibile radia-
tore 2
Perdita refrigerante ® Riparare
o sostituire.
lFlessibile radiatore 3
Campanatura ® Sostituire.
REGOLAZIONE FRIZIONE
1. Controllare:
lGioco libero della frizione a
Fuori specifica ® Regolare.
Gioco libero della frizione
a:
2 ~ 4 mm (0,08 ~ 0,16 in)
2. Regolare:
lGioco della leva della frizione
NOTA:
lEffettuare una minuta regolazione sul
lato della leva utilizzando il disposi-
tivo di regolazione 2.
lDopo la regolazione controllare
l’azionamento corretto della leva della
frizione. Fasi per la regolazione del gioco
libero della frizione:
lSvitare i controdadi 1.
lRegolare il gioco modificando la
posizione di serraggio.
lSerrare i controdadi.

3 - 10
INSP
ADJ
THROTTLE CABLE ADJUSTMENT
THROTTLE CABLE ADJUSTMENT
1. Check:
lThrottle grip free play a
Out of specification ® Adjust.
Throttle grip free play a:
3 ~ 5 mm (0.12 ~ 0.20 in)
2. Adjust:
lThrottle grip free play
Throttle grip free play adjustment steps:
lRemove the throttle cable cover 1.
NOTE:
lBefore adjusting the throttle cable free
play, the engine idle speed should be
adjusted.
lWhen the motorcycle is accelerating,
throttle cable #1 2 is pulled and throttle
cable #2 3 is pushed.
1st step:
lLoosen the locknuts 4 on throttle cable
#2.
lAdjust the free play by changing their
tightening position.
2nd step:
lLoosen the locknuts 5 on throttle cable
#1.
lAdjust the free play by changing their
tightening position.
lTighten the locknuts.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
lInstall the throttle cable cover.
T R..
Throttle cable cover:
4 Nm (0.4 m • kg, 2.9 ft • lb)