Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 296 / 388

THROTTLE BODY
7-7
EAM30271
CHECKING THE INJECTOR
1. Check:
•
Injector
Obstruction

Replace, and check the fuel
pump and the fuel injection system.
Refer to “FUEL INJECTION SYSTEM” on
page 8-15.
Deposits

Replace.
Damage

Replace.
2. Check:
•
Injector resistance
Refer to “CHECKING THE INJECTOR” on
page 8-55.
EAM30272
CHECKING THE THROTTLE BODY
1. Check:
• Throttle body
Cracks/damage

Replace.
2. Check:
•
Fuel passages
Obstructions

Clean.
NOTICE
ECA26070
• Before removing the throttle body, clean
the area around the throttle body to prevent
dirt and other foreign material from falling
into the engine.
• If the throttle body is subject to strong
shocks or dropped during cleaning, re-
place it.
• Do not use any caustic carburetor cleaning
solution.
• Do not directly push the throttle valves to
open them.
• Do not loosen the throttle valve stopper
screw “1”, throttle valve pulley nut “2”,
throttle valve screw “3” or starter knob nut
“4”. A loss of performance may occur.
• Do not use compressed air to clean the
throttle body. Foreign materials may ad-
here to the intake air pressure sensor pas-
sage “a” and fuel injector “b” in the throttle
body.
3. Check:
•
Idle screw “1” passage “a”
Obstruction

Blow out with compressed air.
4. Reset:
• Use the diagnostic code number “87”.
Refer to “DIAGNOSTIC CODE: SENSOR
OPERATION TABLE” on page 9-12.
Yamaha diagnostic tool USB (US)
90890-03269
Yamaha diagnostic tool (A/I)
90890-03264
2
1
3
b
a
4
a
1