Our team has been fighting the weight problem from the opposite direction, but as a result, I may have some helpful advice here. We are using Praga Tacho chassis’, and have had a very difficult time getting some of our drivers to make weight. This is not a shameless pitch for a brand, just something for which I happen to have definitive data. Our kt100 kart weighs in at 147lbs, the leopard at 158, and the stock honda at 200. This leaves about 200 lbs for the driver in kt100 and TaG and 185 in the stock honda. Im sure other manufacturers offer similar chassis weights as well.