2016 YAMAHA YZ450F warning

ELECTRICAL COMPONENTS
8-43
2. Check:
• Stator coil resistance
Out of specification  Replace.
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a. Connect the pocket tester ( 1) to the sta-
tor coil coupler.
b. Measure the stator coil resistance.
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EASB111340CHECKING THE RECTIFIER/REGULATOR
1. Check:
• Rectifier/regulator output voltage
Out of specification  Replace.
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a. Set the digital tachometer to the ignition coil.
b. Connect the pocket tester (20 VDC) to the
rectifier/regulator coupler.c. Start the engine and let it run at about 5000
r/min.
d. Measure the output voltage.
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EASB111341CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove:
• Coolant temperature sensor
EWA
WARNING
• Handle the coolant temperature sensor
with special care.
• Never subject the coolant temperature
sensor to strong shocks. If the coolant
temperature sensor is dropped, replace it.
2. Check:
• Coolant temperature sensor resistance
Out of specification  Replace.
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a. Connect the pocket tester ( 1k/100) to
the coolant temperature sensor. Stator coil resistance
0.624–0.936 
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
White “1”
• Negative tester probe 
White “2”
No load regulated voltage
14.1–14.9 V
Digital tachometer
90890-06760
YU-39951-B
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
12
• Positive tester probe 
Red “1”
• Negative tester probe 
Black “2”
Coolant temperature sensor re-
sistance
2.51–2.78 k at 20°C (68°F)
210–221  at 100°C (212°F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Green/White “1”
• Negative tester probe 
Black/Blue “2”
21
B
WWR

ELECTRICAL COMPONENTS
8-44
b. Immerse the coolant temperature sensor in
a container filled with coolant.
TIP
Make sure the coolant temperature sensor ter-
minals do not get wet.
c. Place a thermometer in the coolant.
d. Slowly heat the coolant, and then let it cool
to the specified temperature indicated in the
table.
e. Check the coolant temperature sensor for
continuity at the temperatures indicated in
the table.
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EASB111342CHECKING THE THROTTLE POSITION
SENSOR
1. Remove:
• Throttle position sensor
(from the throttle body)
EWA
WARNING
• Handle the throttle position sensor with
special care.
• Never subject the throttle position sensor
to strong shocks. If the throttle position
sensor is dropped, replace it.
2. Check:
• Throttle position sensor maximum resis-
tance
Out of specification  Replace.
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a. Connect the pocket tester ( 1k) to the
throttle position sensor.
b. Check the throttle position sensor maximum
resistance.
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3. Install:
• Throttle position sensor
TIP
When mounting the throttle position sensor, ad-
just its angle properly. Refer to “ADJUSTING
THE THROTTLE POSITION SENSOR” on
page 7-9.
12
G/W B/L
B/L G/W
Resistance
6.30 k
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
21

ELECTRICAL COMPONENTS
8-45
EASB111343CHECKING THE THROTTLE POSITION
SENSOR INPUT VOLTAGE
1. Check:
• Throttle position sensor input voltage
Out of specification  Replace the ECU.
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a. Connect the test harness S-pressure sensor
(3P) to the throttle position sensor coupler
and the wire harness.
b. Connect the pocket tester (20 VDC) to the
test harness S-pressure sensor (3P).
c. Start the engine.
d. Measure the throttle position sensor input
voltage.
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EASB111344CHECKING THE INTAKE AIR PRESSURE
SENSOR
1. Check:
• Intake air pressure sensor output voltage
Out of specification  Replace.
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a. Connect the pocket tester (20 VDC) to the
intake air pressure sensor coupler (wire har-
ness side).
b. Start the engine.
c. Measure the intake air pressure sensor out-
put voltage.
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EASB111345CHECKING THE INTAKE AIR TEMPERA-
TURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case)
EWA
WARNING
• Handle the intake air temperature sensor
with special care.
• Never subject the intake air temperature
sensor to strong shocks. If the intake air
temperature sensor is dropped, replace it.
2. Check:
• Intake air temperature sensor resistance
Out of specification  Replace. Throttle position sensor input
voltage
4–6 V
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Test harness S– pressure sensor
(3P)
90890-03207
YU-03207
• Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
Intake air pressure sensor output
voltage
3.57–3.71 V at 101.3 kPa
21
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Pink/Black “1”
• Negative tester probe 
Black/Blue “2”
Intake air temperature sensor re-
sistance
290–390  at 80 °C (176 °F)
12
P/B
P/B

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 previously, but the affected system or component
is currently operating normally.
ACTUATOR OPERATION TABLE62 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
•01Erase 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

CHASSIS
10-2
EASB111369TIRE 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.
EASB111370FRONT 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.
EASB111371CHANGE 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. Standard tire pressure
100 kPa (1.00 kgf/cm
2,15 psi)
Extent of adjustment
60–80 kPa (0.60–0.80 kgf/cm
2,
9–12 psi)
Extent of adjustment
100–120 kPa (1.00–1.20 kgf/cm
2,
15–18 psi)
Standard oil amount
315 cm3 (10.65 US oz, 11.11
lmp.oz)
Extent of adjustment
300–365 cm
3 (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
10-4
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.
EASB111376
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. Standard figure
90–100 mm (3.5–3.9 in)
Length “a” of standard shock
458.5 mm (18.05 in)