Joe, I was re-reading this, and I think instead of changing out the carbs.. it maybe better to do this..
By HondaMan:
Hop-ups: Add 4 teeth to the rear sprocket and get a cam. Don't get high lift, get longer duration - BUT: not a LOT more duration, because it is a small-bore engine. A little goes a long way. Adding 5 degrees of overlap and 10 degrees of duration should be your limit for non-racing driving: it will REALLY wake up the "mid-four". Don't bother with bigger carbs: port it in the head instead. The stock carbs can make a lot more HP than they do: make a "pocket" above the intake valve, then raise the exhaust ports about 2-3 mm and smooth 'em out. This will add up to 10 HP to this neat engine, which is a lot.
Just a thought..
.: Scott :.