Once I really get moving fast on my bike it sort of all the sudden cuts of alot power. It doesn't happen imediantly but only once I sort of get to the max of my revs.(At least thats what it seems like) The engine doesn't turn of, it just looses all it's pulling power and the only way to get the power back is to let up all the gas for a little while and eventualy it's power returns. Is this because of my fuel mixture or somthing like that? I'm running about a 25:1ish mixture...any help would be appreciated!!!