This problem has given me nightmares in the past.
I always find that with two strokes, when your in the top end of the gear and your running rich, it's just one of those things that you can just kind of tell. it never feels quite right when you accelerate and you always know that there is lot more power in there waiting to come out but it just can't get it because it's so rich.
I find carb setting is more of an art than a science (sounds strange I know) but after riding a two stroke for a whilst you just get a feel for when the carb is set right.
I always say that it's better to be a little on the rich side than too lean. a bike running too rich can be sorted with little to no expense, if your too lean, get out the credit card cause something bad is gonna happen sooner or later.
do a search on jetting or running rich or something. it's gotta be one of the most common problems two strokers have to deal with.