Just one point when you are doing the polishing, Pedro. Between the mashing of the needle and the polishing it back into shape, the usual step up at the big end of the taper (marked in red) may come closer to the mixture needle's seat in the carburetor body:
[Linked Image]


That step must always be far enough back to have no influence on the needle setting, so you may have to move it back toward the screw-head by half a millimetre.

A report on how you go with this operation would be very useful to other members.