2014 YAMAHA YZ450F Owners Manual

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
9-6
*1 Symbols used in the explanations of the malfunction history: Normal
: There is currently a malfunction or abnormal condition. : A malfunction or abnormal condition occurred prev iously, but the affected system or component
is currently operating normally.
ACTUATOR OPERATION TABLE 62 Malfunction history ( )
code No. erasure
*1
• There is no history.
• There is some history. •00
• Other: Displays the total
number of ( ) and ( ). Replace all ( ) with ( )
by the operation start pro-
cessing.
64 Setting history display • There is no history.
• There is some history.
• History is unknown (Histo-ry data is damaged). Displays the presence or ab-
sence of the setting history by
Power Tuner.
•00
•01
•02
—
65 Setting map erasure • There is no setting.
• There is some setting. Displays the presence or ab-
sence of the setting history by
Power Tuner.
•00
•01 Erase all setting maps by
the operation start process-
ing.
70 Program version number Displays a program version No.—
Diag-
nostic code No. ITEM Actuation Procedure
30 Ignition coil Actuates the ignition coil five times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the ignition coil is
actuated.Check that a spark is gener-
ated five times.
• Connect an ignition
checker.
36 Injector Actuates the injector five times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the injector is ac-
tuated.TIP: Before performing
this operation, be sure to
disconnect the fuel pump
coupler.
Check that injector is actu-
ated five times by listening
for the operating sound.
Diag-
nostic code No. ITEM Display Procedure

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
9-7

10
TUNING
CHASSIS........................................................................................................ 10-1
SELECTION OF THE SECONDARY REDUCTION 
RATIO (SPROCKET) .............................................................................. 10-1
DRIVE AND REAR WHEEL SPROCKETS SETTING PARTS ................ 10-1
TIRE PRESSURE..................................................................................... 10-2
FRONT FORK SETTING.......................................................................... 10-2
CHANGE IN AMOUNT AND CHARACTERISTICS OF FORK OIL.......... 10-2
SETTING OF SPRING AFTER REPLACEMENT .................................... 10-3
FRONT FORK SETTING PARTS............................................................. 10-3
REAR SUSPENSION SETTING .............................................................. 10-3
CHOOSING SET LENGTH ...................................................................... 10-3
SETTING OF SPRING AFTER REPLACEMENT .................................... 10-4
REAR SHOCK ABSORBER SETTING PARTS ....................................... 10-5
SUSPENSION SETTING (FRONT FORK)............................................... 10-6
SUSPENSION SETTING (REAR SHOCK ABSORBER) ......................... 10-7

CHASSIS
10-1
EAS1SL1365
CHASSIS
EAS1SL1366SELECTION OF THE SECONDARY REDUC-
TION RATIO (SPROCKET)
reduction ratio>
• It is generally said that the secondary gear ra-
tio should be reduced for a longer straight por-
tion of a speed course and should be
increased for a course with many corners. Ac
-
tually, however, as the speed depends on the
ground condition of the day of the race, be
sure to run through the circuit to set the ma
-
chine suitable for the entire course.
• In actuality, it is very difficult to achieve set-
tings suitable for the entire course and some
settings may be sacrificed. Thus, the settings
should be matched to the portion of the
course that has the greatest effect on the race
result. In such a case, run through the entire
course while making notes of lap times to find
the best balance; then, determine the second
-
ary reduction ratio.
• If a course has a long straight portion where a
machine can run at maximum speed, the ma
-
chine is generally set such that it can develop
its maximum revolutions toward the end of the
straight line, with care taken to avoid the en
-
gine over-revving.
TIP
Riding technique varies from rider to rider and
the performance of a machine also vary from
machine to machine. Therefore, do not imitate
other rider's settings from the beginning but
choose your own setting according to the level
of your riding technique.
EAS1SL1367
DRIVE AND REAR WHEEL SPROCKETS
SETTING PARTS
EAS1SL1368
Secondary reduction ratio = Number of
rear wheel sprocket teeth/Number of
drive sprocket teeth
Secondary reduction ra-
tio
3.769 (49/13)
Part nameTypePart number
Drive sprocket “1”
(STD)13T9383E-13233
Rear wheel
sprocket “2”
48T5GS-25448-50
(STD)49T17D-25449-50
50T5TJ-25450-80
52T5TJ-25452-80

CHASSIS
10-2
TIRE PRESSURE
Tire pressure should be adjusted to suit the
road surface condition of the circuit.
• Under a rainy, a muddy, a sandy, or a slippery
condition, the tire pressure should be lower
for a larger area of contact with the road sur
-
face.
• Under a stony or a hard road condition, the
tire pressure should be higher to prevent a flat
tire.
EAS1SL1369FRONT FORK SETTING
The front fork setting should be made depend-
ing on the rider's feeling of an actual run and
the circuit conditions.
The front fork setting includes the following
three factors:
1. Setting of air spring characteristics
• Change the fork oil amount.
2. Setting of spring preload
• Change the spring.
3. Setting of damping force
• Change the compression damping force.
• Change the rebound damping force.
The spring acts on the load and the damping
force acts on the cushion travel speed.
EAS1SL1370CHANGE IN AMOUNT AND CHARACTERIS-
TICS OF FORK OIL
Damping characteristic near the final stroke
can be changed by changing the fork oil
amount.
EWA1DX4001
WARNING
Adjust the oil amount in 5 cm3 (0.2 US oz,
0.2 Imp. 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
cause the air spring characteristics to have
a tendency to be stiffer with the consequent
deteriorated performance and characteris
-
tics. Therefore, adjust the front fork within
the specified range.
EAS1SL1371
Standard tire pressure
100 kPa (1.0 kgf/cm2,15 psi)
Extent of adjustment
60–80 kPa (0.6–0.8 kgf/cm2, 9.0–
12 psi)
Extent of adjustment
100–120 kPa (1.0–1.2 kgf/cm2,
15–18 psi)
Standard oil amount
335 cm3 (11.33 US oz, 11.82
lmp.oz) (USA) (CAN)
355 cm3 (12.00 US oz, 12.52
lmp.oz) (EUR) (JPN) (AUS) (NZL)
(ZAF)
Extent of adjustment
300–365 cm3 (10.14–12.34 US
oz, 10.58–12.87 Imp. oz)
A. Air spring characteristics in relation to oil
amount change
B. Load
C. Stroke
1. Max. oil amount
2. Standard oil amount
3. Min. oil amount

CHASSIS
10-3
SETTING OF SPRING AFTER REPLACE-
MENT
As the front fork setting can be easily affected
by the rear suspension, take care so that the
front and the rear are balanced (in position etc.)
when setting the front fork.
1. Use of soft spring
• Change the rebound damping force.
Turn out one or two clicks.
• Change the compression damping force.
Turn in one or two clicks.
TIP
Generally a soft spring gives a soft riding feel-
ing. Rebound damping tends to become stron-
ger and the front fork may sink deeply over a
series of gaps.
2. Use of stiff spring
• Change the rebound damping force.
Turn in one or two clicks.
• Change the compression damping force.
Turn out one or two clicks.
TIP
Generally a stiff spring gives a stiff riding feel-
ing. Rebound damping tends to become weak-
er, resulting in lack of a sense of contact with
the road surface or in a vibrating handlebar.
EAS1SL1372FRONT FORK SETTING PARTS
• Front fork spring “1”
*Except for USA and CAN
TIP
The I.D. mark (slits) “a” is proved on the end of
the spring.
EAS1SL1373REAR SUSPENSION SETTING
The rear shock absorber setting should be
made depending on the rider's feeling of an ac
-
tual 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 force.
• Change the compression damping force.
EAS1SL1374CHOOSING SET LENGTH
1. Place a stand or a block under the engine to
put the rear wheel above the floor, and mea
-
sure the length “a” between the rear wheel
axle center and the rear fender holding bolt.
Type
Spring
rate
N/mm
Part number
I.D.
Mark
(slits)
SOFT3.91SL-23141-20|-||
4.61SL-23141-30|-|||
STD*4.71SL-23141-10—
1SL-23141-40|-||||
4.81SL-23141-50|-|||||
STD4.91SL-23141-00—
1SL-23141-60||-||
STIFF5.01SL-23141-70||-|||
a
1

CHASSIS
10-4
2. Remove the stand or block from the engine
and, with a rider astride the seat, measure
the sunken length “b” between the rear
wheel axle center and the rear fender hold
-
ing bolt.
3. Loosen the locknut “1” and make adjustment
by turning the adjuster “2” to achieve the
standard figure from the subtraction of the
length “b” from the length “a.”
TIP
• If the machine is new and after it is broken in,
the same set length of the spring may change
because of the initial fatigue, etc. of the
spring. Therefore, be sure to make reevalua
-
tion.
• If the standard figure cannot be achieved by
adjusting the adjuster and changing the set
length, replace the spring with an optional one
and make readjustment.
EAS1SL1375
SETTING OF SPRING AFTER REPLACE-
MENT
After replacement, be sure to adjust the spring
to the set length [sunken length 90–100 mm
(3.5–3.9 in)] and set it.
1. Use of soft spring
• Adjust to decrease rebound damping force
to compensate for less spring load. Run with
the rebound damping force adjuster one or
two clicks turned out, and readjust it to suit
your preference.
2. Use of stiff spring
• Adjust to increase rebound damping force to
compensate for greater spring load. Run
with the rebound damping force adjuster
one or two clicks turned in, and readjust it to
suit your preference.
TIP
Adjusting the rebound damping force will be fol-
lowed more or less by a change in the com-
pression damping force. For correction, adjust
to decrease compression damping force.
EWA1DX4002
WARNING
When using a rear shock absorber other
than currently installed, use the one whose
overall length “a” does not exceed the stan
-
dard as it may result in faulty performance.
Never use one whose overall length is
greater than standard.
EAS1SL1376
Standard figure
90–100 mm (3.5–3.9 in)
Length “a” of standard shock
458.5 mm (18.05 in)

CHASSIS
10-5
REAR SHOCK ABSORBER SETTING
PARTS
• Rear shock spring “1”
*Except for USA and CAN
TIP
• The I.D. mark “a” is marked at the end of the
spring.
• Spring specification varies according to the
color of I.D. marks.
• Extent of adjustment (spring preload)
TIP
For the spring preload adjustment, refer to “AD-
JUSTING THE REAR SHOCK ABSORBER
ASSEMBLY” on page 3-30.
Type
Spring
rate
N/mm
Part numberI.D.
Mark
SOFT
52
1SL-22212-40
(Blue)
Yellow1SL-22212-50
(Red)
54
1SL-22212-60
(Blue)
Pink1SL-22212-70
(Red)
STD*56
1SL-22212-20
(Blue)
White1SL-22212-30
(Red)
STD58
1SL-22212-00
(Blue)
Silver1SL-22212-10
(Red)
STIFF60
1SL-22212-80
(Blue)
Brown1SL-22212-90
(Red)
MaximumMinimum
Position in which
the spring is turned
in 18 mm (0.71 in)
from its free length.Position in which
the spring is turned
in 1.5 mm (0.06 in)
from its free length.