Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 297 / 388

THROTTLE BODY
7-8
EAM30268
CHECKING THE FUEL PRESSURE
1. Check:
•
Fuel pressure
a. Remove the side cover (left/right), the seat
and the shroud (left/right).
Refer to “GENERAL CHASSIS” on page
4-1.
b. Remove the fuel tank bolt and lift the fuel
tank.
c. Disconnect the fuel hose from the fuel
pump.
Refer to “REMOVING THE FUEL TANK”
on page 7-2.
WARNING
EWA19380
Cover the fuel hose connection with a cloth
when disconnecting it. This is because re-
sidual pressure in the fuel hose could cause
fuel to spurt out when the hose is removed.
NOTICE
ECA24750
Make sure that the fuel hose is disconnected
by hand. Do not forcibly disconnect the hose
with tools.
d. Connect the pressure gauge “1” and the
fuel pressure adapter “2” to the fuel hose.
e. Start the engine.
f. Measure the fuel line pressure.
Out of specification

Replace the fuel
pump.
EAM30273
ADJUSTING THE THROTTLE POSITION
SENSOR
WARNING
EWA15950
• 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.
1. Check:
• Throttle position sensor
Refer to “CHECKING THE THROTTLE PO-
SITION SENSOR INPUT VOLTAGE” on
page 8-53.
2. Adjust:
•
Throttle position sensor angle
a. Connect the Yamaha diagnostic tool.
Refer to “YAMAHA DIAGNOSTIC TOOL”
on page 8-17.
b. Temporary tighten the throttle position
sensor.
c. Check that the throttle grip is fully closed.
d. Connect the throttle position sensor to the
wire harness.
e. Set the Yamaha diagnostic tool to “diag-
nostic mode”.
f. Choose the diagnostic code No. “01”.
g. Adjust the throttle position sensor mount-
ed angle until “11”–“14” appears on the
Yamaha diagnostic tool.
h. After adjusting the throttle position sensor
mounted angle, tighten the throttle posi-
tion sensor screw “1”.
Pressure gauge
90890-03153
Pressure gauge
YU-03153
Fuel pressure adapter
90890-03186
Fuel pressure adapter
YM-03186
1 1 1
2 2
Fuel line pressure (at idle)
300–390 kPa (3.0–3.9 kgf/cm²,
43.5–56.6 psi)
Yamaha diagnostic tool USB (US)
90890-03269
Yamaha diagnostic tool (A/I)
90890-03264
Throttle position sensor screw
3.5 N·m (0.35 kgf·m, 2.6 lb·ft)
T
R
.
.