Wow old thread.

#1 more cubes. #2 longer lever

I personally would not stroke a motor if I have to sacrifice rod ratio. I have never personally never got along with short rod motors, like early CR500 and Chevy small block 400. There are lots of good internet articles that talk about rod ratio and how it affects the engine, so I won't go into detail here. But it does affect piston dwell at tdc and btc; the rod/crank angle; the rate at which the piston accelerates or accelerates at a given point in the stroke; and the corresponding effect of the port timing in two strokes.

It would think it would have little overall effect on case compreasion. Not only does the piston travel higher at tdc which lets in more air, but it travels deeper into the case at btc pushing out more air. But has already been stated, this is of less concern with modern pipes.

I have a 650. I have riden a new superjet and would not trade my 650 for it. Definitely some handling diferences, but it was no match for hole shot or top speed.