I could be wrong but I don't think the CDI would cause the bike to stumble there, as far as functioning as a rev limiter. I think that's the engines feasible limits based on design(rotating mass, inertia and all that fun stuff) and the carb size. Well, probably most of all the carb size. Hopefully someone else will chime in with a more precise answer. I think with a lighter piston or decreasing any moving internal mass would provide a performance gain on some level. But its never really a good idea to paint such broad strokes in regards to engines. They are all very different. I think Glen has a better idea than me..