ESP YAMAHA YZ450F 2007 Owner's Manual

5 - 64
CHAS
EC586000
HANDLING NOTE
WARNING
This shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the shock absorber into an
open flame or other high heat. The
shock absorber may explode as a result
of nitrogen gas expansion and/or dam-
age to the hose.
3. Be careful not to damage any part of the
gas tank. A damaged gas tank will impair
the damping performance or cause a
malfunction.
4. Take care not to scratch the contact sur-
face of the piston rod with the cylinder;
or oil could leak out.
5. Never attempt to remove the plug at the
bottom of the nitrogen gas tank. It is
very dangerous to remove the plug.
6. When scrapping the shock absorber, fol-
low the instructions on disposal.
EC587000
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the shock absorber, be sure
to extract the nitrogen gas from valve 1. Wear
eye protection to prevent eye damage from
escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
REAR SHOCK ABSORBER

5 - 64
CHAS
REMARQUES CONCERNANT LA
MANIPULATION
AVERTISSEMENT
Cet amortisseur est équipé d’un réservoir indé-
pendant contenant de l’azote sous haute pres-
sion. Afin d’éviter tout danger d’explosion, lire
attentivement les informations ci-dessous avant
de manipuler l’amortisseur arrière.
Le fabricant décline toute responsabilité pour
les dommages matériels ou corporels résultant
d’une mauvaise manipulation.
1. Ne jamais essayer de démonter le cylindre ou
le réservoir.
2. Ne jamais jeter un amortisseur usagé au feu
ou l’exposer à une chaleur intense. L’amor-
tisseur risque d’exploser en raison de la dila-
tation de l’azote et/ou de l’endommagement
de la durit.
3. Veiller à n’endommager aucune partie du
réservoir de gaz. Un réservoir endommagé
affectera la capacité d’amortissement ou
entraînera un mauvais fonctionnement.
4. Veiller à ne pas rayer la surface de contact de
la tige de piston avec le cylindre afin d’éviter
tout risque de fuite d’huile.
5. Ne jamais essayer d’enlever le bouchon du
fond du réservoir d’azote. Il est très dange-
reux d’enlever ce bouchon.
6. Pour la mise au rebut de l’amortisseur, sui-
vre les instructions spécifiques.
REMARQUES CONCERNANT LA MISE AU
REBUT (CONCESSIONNAIRES YAMAHA
UNIQUEMENT)
Avant de mettre l’amortisseur au rebut, ne pas
oublier d’évacuer l’azote par la soupape 1. Mettre
des lunettes pour se protéger du gaz et/ou des parti-
cules de métal susceptibles de s’échapper.
AVERTISSEMENT
Confier la mise au rebut d’un amortisseur
endommagé ou usé à un concessionnaire
Yamaha.HANDHABUNGSHINWEISE
WARNUNG
Der Stoßdämpfer und Ausgleichsbehälter
enthalten Stickstoff unter hohem Druck.
Deshalb vor Arbeiten am Federbein die fol-
genden Hinweise sorgfältig lesen und die
Sicherheitsratschläge befolgen.
Der Hersteller übernimmt keinerlei Haftung
für Unfälle, Verletzungen oder Schäden, die
auf unsachgemäße Behandlung des Stoß-
dämpfers zurückzuführen sind.
1. Den Stoßdämpfer unter keinen Umstän-
den öffnen oder manipulieren.
2. Den Stoßdämpfer und Gaszylinder von
Hitze und offenen Flammen fern halten
Der Stoßdämpfer kann aufgrund eines
Stickstoff-Druckanstiegs und/oder einer
Beschädigung des Schlauchs explodie-
ren.
3. Darauf achten, dass der Ausgleichsbe-
hälter nicht beschädigt wird. Ein beschä-
digter Ausgleichsbehälter beeinträchtigt
die Funktion des Federbeins.
4. Darauf achten, dass die Gleitfläche des
Dämpferrohrs nicht verkratzt wird, um
Ölaustritt zu vermeiden.
5. Der Verschluss an der Unterseite des
Ausgleichsbehälter darf unter keinen
Umständen abgenommen werden. Dies
ist außerordentlich gefährlich.
6. Den Stoßdämpfer sachgerecht (den Her-
steller-Anweisungen entsprechend) ent-
sorgen.
HINWEISE ZUR ENTSORGUNG (NUR
YAMAHA-HÄNDLER)
Vor der Entsorgung muss das Stickstoffgas
durch das Ventil 1 entfernt werden. Unbedingt
eine Schutzbrille tragen, um Augenverletzun-
gen durch ausströmendes Gas oder umherflie-
gende Metallspäne zu vermeiden.
WARNUNG
Die Entsorgung des Stoßdämpfers sollte
am besten dem Yamaha-Händler überlas-
sen werden.
AMORTISSEUR ARRIERE
FEDERBEIN

–+ELEC
6 - 2
MAP-CONTROLLED CDI UNIT
MAP-CONTROLLED CDI UNIT
A map-controlled, CDI ignition system is used in the YZ450F.
The microcomputer in the CDI unit detects the engine speed and throttle position, thus determining
the optimum ignition timing through the entire operating range. In this way, quick throttle response
can be achieved according to various riding conditions.
Throttle position sensorCDI unitIgnition coil
Pickup coilCDI magneto rotor

Function of Component
Component Function
TPS
(throttle position sensor)Detects throttle valve opening and inputs it into the computer in the
CDI unit as a throttle opening signal.
Pickup coil Detects signal rotor revolutions and inputs them into the computer in
the CDI unit as engine revolution signals.
CDI unit The signals of the TPS and pickup coil sensor are analyzed by the
computer in the CDI unit, which then adjusts ignition timing for the
operation requirements.

Principal of 3-Dimensional Control
Conventionally, ignition timing was controlled only
by engine revolutions (2-dimensional control).
However, ignition timing needs advancement also
by engine load. Thus, accurate ignition timing can
be determined by adding throttle opening to deter-
mine ignition timing (3-dimensional control).
3-D Image Map of Ignition Timing
(different from actual characteristics)
Ignition timing
Thr
ot
tl
e
ope
ni
ngR
evo
l
ut
io
ns

7 - 1
TUN
EC700000
TUNING
EC710000
ENGINE
Carburetor setting
•The air/fuel mixture will vary depending on
atmospheric conditions. Therefore, it is nec-
essary to take into consideration the air pres-
sure, ambient temperature, humidity, etc.,
when adjusting the carburetor.
•Perform a test run to check for proper engine
performance (e.g., throttle response) and
spark plug(-s) discoloration or fouling. Use
these readings to determine the best possi-
ble carburetor setting.
NOTE:
It is recommended to keep a record of all car-
buretor settings and external conditions (e.g.,
atmospheric conditions, track/surface condi-
tions, lap times) to make future carburetor set-
ting easier.
WARNING
The carburetor is a part of the fuel line.
Therefore, be sure to install it in a well-
ventilated area, away from flammable
objects and any sources of fire.
Never look into the carburetor intake.
Flames may shoot out from the pipe if the
engine backfires while it is being started.
Gasoline may be discharged from the
accelerator pump nozzle when the carbu-
retor has been removed.
SETTING

7 - 10
TUN
Examples of carburetor setting depending on symptom
This should be taken simply for an example. It is necessary to set the carburetor while checking
the operating conditions of the engine.
Symptom Setting Checking
At full throttle
Hard breathing
Shearing noise
Whitish spark plug
Lean mixtureIncrease main jet calibration no.
(Gradually)
Discoloration of spark plug
→
If tan color, it is in good condition.
If cannot be corrected:
Clogged float valve seat
Clogged fuel hose
Clogged fuel cock
Check that the accelerator pump
operates smoothly.
At full throttle
Speed pick-up stops
Slow speed pick-up
Slow response
Sooty spark plug
Rich mixtureDecrease main jet calibration no.
(Gradually)
Discoloration of spark plug
→
If tan color, it is in good condition.
If cannot be corrected:
Clogged air cleaner
Fuel overflow from carburetor
Lean mixture Lower jet needle clip position.
(1 groove down)
The clip position is the jet needle
groove on which the clip is installed.
The positions are numbered from the
top.
Check that the accelerator pump oper-
ates smoothly (except for rich mixture
symptom). Rich mixture Raise jet needle clip position.
(1 groove up)
1/4 ~ 3/4 throttle
Hard breathing
Lack of speedLower jet needle clip position.
(1 groove down)
1/4 ~ 1/2 throttle
Slow speed pick-up
Poor accelerationRaise jet needle clip position.
(1 groove up)
Closed to 1/4 throttle
Hard breathing
Speed downUse jet needle with a smaller diame-
ter.Slow-speed-circuit passage
Clogged
→ Clean.
Overflow from carburetor
Closed to 1/4 throttle
Poor accelerationUse jet needle with a larger diameter.
Raise jet needle clip position. (1
groove up)
Poor response in the low to
intermediate speedsRaise jet needle clip position.
If this has no effect, lower the jet nee-
dle clip position.
Poor response when throt-
tle is opened quicklyCheck overall settings.
Use main jet with a lower calibration
no.
Raise jet needle clip position.
(1 groove up)
If these have no effect, use a main jet
with a higher calibration no. and lower
the jet needle clip position.Check air cleaner for fouling.
Check that the accelerator pump
operates smoothly.
Jet needleClip
Groove 7 Groove 6
Groove 5
Groove 4
Groove 3
Groove 2
Groove 1
Leaner
↑
(Standard)
↓
Richer
*
SETTING

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TUN
EC72P000
Front fork setting parts
•Front fork spring 1
NOTE:
The I.D. mark (slits) a is proved on the end of
the spring.TYPESPRING
RATESPRING
PART NUMBERI.D.
MARK
(slits)
SOFT0.398
0.408
0.418
0.428
0.438
0.449
0.4591C3-23141-A1
1C3-23141-B1
1C3-23141-C1
1C3-23141-D1
1C3-23141-E1
1C3-23141-F1
1C3-23141-G1I
II
III
IIII
IIIII
I-I
I-II
STD 0.469 2S2-23141-L1–
STIFF 0.479 1C3-23141-J1 I-IIII
EC72B000
Rear suspension setting
The rear suspension setting should be made
depending on the rider’s feeling of an actual
run and the circuit conditions.
The rear suspension setting includes the fol-
lowing two factors:
1. Setting of spring preload
•Change the set length of the spring.
•Change the spring.
2. Setting of damping force
•Change the rebound damping.
•Change the compression damping.
SETTING

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TUNSETTING
EC72Q000
Rear shock absorber setting parts
•Rear shock spring 1
[Equal-pitch titanium spring]
[Equal-pitch steel spring]
[Unequal-pitch steel spring]
CAUTION:
Install the spring seat
2 to the titanium
spring.
NOTE:
•The unequal-pitch spring is softer in initial
characteristic than the equal-pitch spring and
is difficult to bottom out under full compres-
sion.
•The I.D. mark a is marked at the end of the
spring.
•Spring specification varies according to the
color and quantity of I.D. marks.
TYPESPRING
RATESPRING
PART NUMBERI.D.
MARKSPRING
FREE
LENGTH
(approx.)
SOFT4.5
4.7
4.9
5.1
5.31C3-22212-00
1C3-22212-10
1C3-22212-20
1C3-22212-30
1C3-22212-40Green
Red
Black
Blue
Yellow265
265
265
265
275
STD 5.5 1C3-22212-50 Pink 275
STIFF 5.7 1C3-22212-60 White 275
TYPESPRING
RATESPRING
PART NUMBERI.D.
MARK/
Q’TYSPRING
FREE
LENGTH
4.3 5UN-22212-00 Brown/1 260
TYPESPRING
RATE
(approx.)SPRING
PART NUMBERI.D.
MARK/
Q’TYSPRING
FREE
LENGTH
SOFT
STIFF4.5
4.7
4.9
5.1
5.3
5.5
5.75UN-22212-A0
5UN-22212-B0
5UN-22212-C0
5UN-22212-D0
5UN-22212-E0
5UN-22212-F0
5UN-22212-G0Green/2
Red/2
Black/2
Blue/2
Yellow/2
Pink/2
White/2275
275
275
275
275
275
275
a2 12

TUN
Einstellbereich (Federlänge)
[Titanfeder]
[Stahlfeder]
UNGESPANNTE LÄNGE EINSTELLBEREICH b
Circa 265 mm (10,43 in)Eine Kennmarkierung
245,5–263,5 mm
(9,67–10,37 in)
Zwei Kennmarkierungen
251,5–269,5 mm
(9,90–10,61 in)
Drei Kennmarkierungen
243,0–261,0 mm
(9,57–10,28 in)
Circa 275 mm (10,83 in)Eine Kennmarkierung
255,5–273,5 mm
(10,06–10,77 in)
Zwei Kennmarkierungen
261,5–279,5 mm
(10,30–11,00 in)
Drei Kennmarkierungen
253,0–271,0 mm
(9,96–10,67 mm)
UNGESPANNTE LÄNGE EINSTELLBEREICH b
260 mm (10,24 in)240,5–258,5 mm
(9,47–10,18 in)
275 mm (10,83 in)255,5–273,5 mm
(10,06–10,77 in)
REGLAGE
EINSTELLUNG
Plage de réglage (longueur du ressort)
[Ressort en titane]
[Ressort acier]
LONGUEUR LIBRE DU
RESSORTPLAGE DE REGLAGE b

Approx. 265 mm (10,43 in)Un seul repère d’identifica-
tion
245,5 à 263,5 mm
(9,67 à 10,37 in)
Deux repères d’identifica-
tion
251,5 à 269,5 mm
(9,90 à 10,61 in)
Trois repères d’identifica-
tion
243,0 à 261,0 mm
(9,57 à 10,28 in)
Approx. 275 mm (10,83 in)Un seul repère d’identifica-
tion
255,5 à 273,5 mm
(10,06 à 10,77 in)
Deux repères d’identifica-
tion
261,5 à 279,5 mm
(10,30 à 11,00 in)
Trois repères d’identifica-
tion
253,0 à 271,0 mm
(9,96 à 10,67 in)
LONGUEUR LIBRE DU
RESSORTPLAGE DE REGLAGE b

260 mm (10,24 in)240,5 à 258,5 mm
(9,47 à 10,18 in)
275 mm (10,83 in)255,5 à 273,5 mm
(10,06 à 10,77 in)
7 - 19