Yamaha YZ450F Owner's Service Manual page 223

Test harness S–pressure
sensor (3P):
YU-03207/90890-03207
3. Connect the FI diagnostic tool
sub-wire harness to a battery, and
then set the switch on the harness
to "ON".
When checking the atmospheric
pressure sensor, do not start the
engine.
4. Measure the atmospheric pres-
sure sensor output voltage.
Tester se-
Output volt-
lector posi-
age
3.4–3.8 V
Out of specification → Replace.
CHECKING THE RECTIFIER/
REGULATOR
1. Connect:
• Connect the tester to the coupler
for connecting optional part
Tester (+) lead → Red lead "1"
Tester (-) lead→ Black/White lead
"2"
2. Start the engine.
3. Check:
• Rectifier/regulato output voltage
Tester se-
Output volt-
lector posi-
age
14.1–14.9 V
Out of specification → Replace.
4. Stop the engine.
CHECKING THE FUEL INJECTORS
1. Remove:
• Seat
• Fuel tank
• Air filter case
2. Check:
•Injector resistance
3. Connect:
• Tester
Tester (+) lead → Injector termi-
nal "1"
Tester (-) lead → Injector termi-
nal "2"
Injector re-
(20°C, 68°F)
tion
Out of specification → Replace.
DCV
R Lg
B/W
tion
DCV
ELECTRICAL COMPONENTS
Tester se-
lector posi-
sistance
tion
12.0 Ω
Ω×10
7-37