Have a question or 2 that I'm hoping someone can help me with. I have an open animal with a big valve head, and have a new 28mm Clements flat slide carb on the way for it. My question is, do these carbs need jets to tune them for my engine or do they use a needle to tune them? I'm not familiar with flat slide carbs at all, my animal has a Tilly carb on it right now, and a small one at that, being a E.C 304wxa. Any info appreciated