Yamaha WR450FB 2012 Owner's Service Manual page 358

ELECTRICAL COMPONENTS
1. Main switch
2. Clutch switch
3. Fuel sender
4. Fuel pump
5. Intake air pressure sensor
6. Throttle position sensor
7. Injector
8. Intake air temperature sensor
9. Coupler for connecting optional part
10. Ignition coil •
9-57