Running a port matched A35 stock cylinder with a slightly widened exhaust port window. Worried that after hitting high revs and backing off that the idle mixture might not be rich enough. This is my first Dellorto experience and since there's no needle to raise (like on a bing) I'm worried about seizing the motor. Do I need to replace the tube inside with holes in it for something with slightly larger holes? Or will it be fine? 14/12 Dellorto with K & N filter.