2005 YAMAHA YZ250LC oil

7-2
SETTINGTUN
That is:
9Higher temperature expands the air with its
resultant reduced density.
9Higher humidity reduces the amount of oxygen
in the air by so much of the water vapor in the
same air.
9Lower atmospheric pressure (at a high altitude)
reduces the density of the air.
EC713001
Test run
After warming up the engine equipped with the
standard type carburetor(s) and spark plug(s),
run two or three laps of the circuit and check the
smooth operation of the engine and discoloration
of spark plug(s).
åNormal
∫Over burned (too lean)
çOil fouled (too rich)
Discoloration Condition of spark plug
NormalInsulator is dry and
burnt brown.
Over burned
Insulator is whitish.
(too lean)
Oil fouled Insulator is sooty and
(too rich) wet.
A
B
C
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7-12
SETTINGTUN
EC71M010
Change of the heat range of spark plugs
Judging from the discoloration of spark plugs, if
they are found improper, it can be corrected by
the following two methods; changing carburetor
settings and changing the heat range of spark
plug.
9In principle, it is advisable to first use spark
plugs of standard heat range, and judging from
the discoloration of spark plugs, adjust carbure-
tor settings.
9If the calibration No. of the main jet must be
changed by ±15, it is advisable to change the
heat range of spark plugs and newly select the
proper main jet.
NOTE:
9When checking the discoloration of spark
plugs, be sure to stop the engine immediately
after a run and check.
9Avoid racing.
9When changing the heat range of spark plugs,
never attempt to change it more than ±1 rank.
9When using a spark plug other than standard,
check its heat range against the standard and
check that it is a resistance type.
9Note that even if the discoloration seems prop-
er, it may slightly vary with the spark plug
maker and oil in use.
Standard spark plugBR8EG/NGK(resistance type)
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7-15
SETTINGTUN
A
EC722011
Front fork setting
The front fork setting should be made depending
on the rider’s feeling of an actual run and the cir-
cuit conditions.
The front fork setting includes the following three
factors:
1. Setting of air spring characteristics
9Change the fork oil amount.
2. Setting of spring preload
9Change the spring.
9Install the adjustment washer.
3. Setting of damping force
9Change the compression damping.
9Change the rebound damping.
The spring acts on the load and the damp-
ing force acts on the cushion travel speed.
EC723001
Change in amount and characteristics of fork
oil
Damping characteristic near the final stroke can
be changed by changing the fork oil amount.
cC
Adjust the oil amount in 5 cm3(0.2 Imp oz,
0.2 US oz) increments or decrements. Too
small oil amount causes the front fork to
produce a noise at full rebound or the rider
to feel some pressure on his hands or
body. Alternatively, too large oil amount
will develop unexpectedly early oil lock
with the consequent shorter front fork trav-
el and deteriorated performance and char-
acteristics. Therefore, adjust the front fork
within the specified range.
åAir spring characteristics in relation to oil amount
change
∫Load
çStroke
1Max. oil amount
2Standard oil amount
3Min. oil amount
Standard oil amount:
245 cm
3(8.62 Imp oz, 8.28 US oz)
Extent of adjustment:
200~300 cm
3(7.04~10.6 Imp oz,
6.76~10.1 US oz)
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7-15
REGLAGE
EINSTELLUNG
REGISTRAZIONETUN
Einstellung der Vorderradgabel
Die Einstellung der Vorderradgabel
soll entsperechend dem Gefühl des
Fahrers nach einer Testfahrt und den
Bedingungen der Strecke vorgenom-
men werden.
Die Einstellung der Vorderradgabel bein-
haltet die folgenden dreiFaktoren:
1. Einstellung der Luftfedereigen-
schaften
9Änderung des Gabelölmenge
2. Einstellung der Federvorspan-
nung
9Umstellung der Feder
9Die Einstellscheibe einbauen.
3. Einstellund der Dämpfungskraft
9Änderung der Einfederdämp-
fung
9Änderung der Ausfederdämp-
fung
Die Federn wirken auf die Last
ein, und die Dämpfungskraft
wirkt auf die Dämpfungsele-
ment-Bewegungsgeschwindig-
keit.
Änderungen bei der Menge und
den Eigenschaften des Gabelöls
Die Dämpfungseigenschaften beim
letzten Stoß können durch die Ände-
rung der Gabelölmenge verändert
werden.
dD
Die Ölmenge in Schritten von 5 cm3
(0,2 Imp oz, 0,2 US oz) erhöhen oder
verringern. Eine zu kleine Ölmenge
führt bei vollem Rückstoß zu einem
durch die Teleskopgabel produzier-
ten Geräusch, oder dazu, dass der
Fahrer en seinen Händen oder an
seinem Körper einen Druck wahr-
nimmt. Eine zu große Ölmenge wie-
derum führt zu einer unerwartet
frühen Ölblockade, die den Tele-
skopgabel-Federweg verkürzt und
ihre Leistung und Eigenschaften
beeinträchtigt. Die Teleskopgabel
aus diesem Grund innerhalb des
spezifizierten Bereichs einstellen.
Réglages de la fourche avant
Régler la fourche avant en fonction de
la sensation lors de la conduite ainsi
que des conditions du terrain.
Les trois réglages de la fourche avant
sont les suivants:
1. Réglage de l’amortissement pneu-
matique
9Ajuster le quantité de l’huile de
fourche.
2. Réglage de la précontrainte du res-
sort
9Changer de type de ressort.
9Monter la rondelle d’ajustage.
3. Réglage de l’amortissement
9Régler la force de compression.
9Régler la force de rebond.
Le ressort a une action sur la
charge et la suspension a une
action sur la vitesse de la course
d’amortissement.
Changement de quantité et de carac-
téristiques de l’huile de fourche
Les caractéristiques d’amortissement
près de la course finale peuvent être
modifiées en changeant la quantité
d’huile de fourche.
fF
Ajuster la quantité d’huile par incré-
ments ou décréments de 5 cm3(0,2
Imp oz, 0,2 US oz). Avec une quantité
d’huile insuffisante, la fourche émet
un bruit au rebond maximum, ou
alors le pilote ressent une pression
sur ces mains ou son corps. A l’inver-
se, une trop grande quantité d’huile
développe une butée en compression
anticipée imprévisible et une course
de fourche plus courte en conséquen-
ce et une détérioration des perfor-
mances et des caractéristiques. Voilà
pourquoi il convient d’ajuster la
fourche dans la plage spécifiée.
IC722011
Registrazione della forcella anteriore
La registrazione della forcella anteriore
dovrebbe essere effettuata in base alla sen-
sazione che il guidatore ha di una corsa
effettiva e alle condizioni del circuito.
La registrazione della forcella anteriore
comprende i seguenti tre fattori:
1. Registrazione delle caratteristiche
della sospensione pneumatica
9Cambiare il quantità d’olio della
forcella.
2. Registrazione del precarico della
molla
9Cambiare la molla.
9Installare la rondella di regola-
zione.
3. Registrazione della forza di smor-
zamento
9Cambiare lo smorzamento della
compressione.
9Cambiare lo smorzamento
dell’estensione.
La molla agisce sul carico e la
forza di smorzamento agisce
sulla velocità di corsa
dell’ammortizzatore.
IC723001Modifica della quantità e delle carat-
teristiche dell’olio per forcella
Le caratteristiche di smorzamento in
prossimità della corsa finale possono
essere modificate modificando la quan-
tità d’olio per forcella.
iI
Regolare la quantità d'olio in incre-
menti o decrementi di 5 cm3(0,2 Imp
oz, 0,2 US oz). Una quantità d'olio
insufficiente fa sì che la forcella ante-
riore produca un rumore in piena
estensione o che il guidatore avverta
una certa pressione sulle mani o sul
corpo. Una quantità d'olio eccessiva
provocherà invece molto presto un
blocco dell’olio inatteso: la corsa della
forcella sarà più corta e le prestazioni
e le caratteristiche saranno peggiora-
te. Quindi la forcella anteriore deve
essere regolata entro la gamma speci-
ficata.
Quantité d’huile stan-
dard :
245 cm
3(8,62 Imp oz,
8,28 US oz)
Etendue de réglage:
200~300 cm
3
(7,04~10,6 Imp oz,
6,76~10,1 US oz)
ACaractéristiques de ressort pneumatique
en relation avec le changement de quanti-
té d’huile
BCharge
CCourse
1Quantité d’huile max.
2Quantité d’huile standard
3Quantité d’huile min.
Standard-Ölmenge:
245 cm3(8,62 Imp oz,
8,28 US oz)
Einstellumfang:
200~300 cm
3
(7,04~10,6 Imp oz,
6,76~10,1 US oz)
Quantità d’olio standard:
245 cm3(8,62 Imp oz,
8,28 US oz)
Gamma di regolazione:
200~300 cm
3
(7,04~10,6 Imp oz,
6,76~10,1 US oz)
ALuftfedereigenschaften im Verhältnis
zur Änderung der Ölmenge
BBelastung
CFederweg
1Max. Ölmenge
2Standard-Ölmenge
3Min. ÖlmengeACaratteristiche della sospensione pneu-
matica in relazione alla variazione della
quantità d'olio
BCarico
CCorsa
1Quantità d'olio max.
2Quantità d'olio normale
3Quantità d'olio min.
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7-23
SETTINGTUN
EC72H010
Suspension setting
9Front fork
NOTE:
9If any of the following symptoms is experienced with the standard position as the base, make reset-
ting by reference to the adjustment procedure given in the same chart.
9Before any change, set the rear shock absorber sunken length to the standard figure 90~100 mm
(3.5~3.9 in).
Section
Symptom
JumpLarge
Medium Small Check Adjust
gap gap gap
Compression damping Turn adjuster counterclockwise (about 2 clicks)
Stiff over entire to decrease damping.
range111Oil amount Decrease oil amount by about 5~10 cm
3(0.2~0.4
Imp oz, 0.2~0.3 US oz).
Spring Replace with soft spring.
Outer tube Check for any bends, dents, and other notice-
Unsmooth Inner tube able scars, etc. If any, replace affected parts.
movement over 1111Slide metal Replace with a new one for extended use.
entire rangePiston metal Replace with a new one for extended use.
Under bracket tightening Retighten to specified torque.
torque
Poor initial Rebound damping Turn adjuster counterclockwise (about 2 clicks)
movement1to decrease damping.
Oil seal Apply grease in oil seal wall.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
Soft over entire crease damping.
range, bottoming 11Oil amount Increase oil amount by about 5~10 cm
3(0.2~0.4
outImp oz, 0.2~0.3 US oz).
Spring Replace with stiff spring.
Stiff toward stroke
1Oil amountDecrease oil amount by about 5 cm
3(0.2 Imp oz,
end0.2 US oz).
Soft toward stroke
1Oil amountIncrease oil amount by about 5 cm
3(0.2 Imp oz,
end, bottoming out 0.2 US oz).
Stiff initial
1111Compression dampingTurn adjuster counterclockwise (about 2 clicks)
movement to decrease damping.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Low front, tending Rebound damping Turn adjuster counterclockwise (about 2 clicks)
to lower front 11to decrease damping.
postureBalance with rear end Set sunken length for 95~100 mm (3.7~3.9 in)
when one passenger is astride seat (lower rear
posture).
Oil amount Increase oil amount by about 5 cm
3(0.2 Imp oz,
0.2 US oz).
Compression damping Turn adjuster counterclockwise (about 2 clicks)
to decrease damping.
“Obtrusive” front, Balance with rear end Set sunken length for 90~95 mm (3.5~3.7 in)
tending to upper 11when one passenger is astride seat (upper rear
front postureposture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about 5~10 cm
3(0.2~0.4
Imp oz, 0.2~0.3 US oz).
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