OK it's possible that needle is either in the wrong way or is getting stuck. I have had a few that the needle seems alright but in fact just wouldn't move to allow fuel through.You could pull the face off and keep it together as if it were together move the float up and down (Not to far) and see if the needle comes out freely on its own.If it doesn't or comes out slowly or staggers out like it is drunk (Well it maybe high off the fuel) then that could well be the problem. Either way that proves to me that it is a carby issue.
