Originally Posted by Pleiades

High pitch whine from fuel tank + Error 46 = Fuel pump on its way out

Usually caused by wear in the motor causing it to draw a larger than normal current which in turn causes a voltage drop in the FI system, and this is what causes the ECU to flag up a 46 code.

Don't fret though. Although the Yamaha price an eye-watering �550, you can split open the pump's housing and replace the actual pump inside for around �30/40. There are many sellers on ebay offering suitable pumps for XTs. DO NOT go to a dealer because all they will offer you is a complete Yamaha pump assembly, plus fitting/labour, which will more than likely end up heading the direction of a four figure sum!