I was taught you need at least an inch clearance from air intake to cowl in order for a side-intake engine to breathe well. If you don't have the inch, then you need a breather hole in the cowl. If you get the Great Planes stack (aluminum tube with angled end), you can cut the end of the tube so it extends almost to the cowl, but still short enough for the cowl to slip right over it. (You don't really need the angled end.) That way you can still get good breathing, and you can choke with your fingertip instead of the choke plate. Nothing chokes like a fingertip, plus you can feel the wet gas so you know you're drawing fuel.