Yamaha Motor YZ250F 2005 Manuel D'atelier Du Proprietaire page 612

THROTTLE POSITION SENSOR SYSTEM
INSPECTION STEPS
If the throttle position sensor will not operate, use the following inspection steps.
Check entire ignition
system for connection.
OK
Check throttle position
sensor.
OK
*Check CDI magneto.
OK
Check CDI unit.
* marked: Refer to "IGNITION SYSTEM" section.
NOTE:
Use the following special tools in this inspection.
Pocket tester:
YU-3112-C/90890-03112
THROTTLE POSITION SENSOR SYSTEM
Throttle posi-
tion sensor coil
Charging coil
Throttle posi-
tion sensor
input voltage
No good
No good
No good
No good
6 - 7
– +
ELEC
Repair or replace.
Replace.
Replace.
Replace.