Wouldn't even begin to know the answer to that question. We don't know the size of your tires, what your gear ratio is, what your kart weighs, what terrain, and what rpm it caps out at.
what kind of chainsaw was it?
i have a still clutch/chainsaw i was wondering i could find a bell housing and sprocket for it and use the chainsaw engine of course.
A 31cc weedie engine likely won't do much for you (unless it's mounted on a skateboard). As for the clutch question- a)as long as it fits your engine's PTO shaft, and b) as long as you have a way of mounting a proper drive sprocket on the drum.