If you keep the original cylinder, go for a LeoVince handmade S. It gives really good performance from your original parts. Also it looks good, because its straight. I think those "curved" ones are not so good looking in DNA. With the 17,5 mm dellorto, I have a 72-76 main jet and the metal plate from carburator is removed. Also I have enlarged the hole inside the air filter box. But I havenĀ“t removed the "snorkel".