That's one of the reason's I'm doing more with my car and less with my karts at the moment, in the past 18 races, I've won 15 and taken 3 2nd's, and that's in the fastest non-shifter class [2-cycle], with me running my plain ole Piston-port 100cc Yamaha against 100cc Reed valve two-strokes on karts with 4 wheel brakes [I just have to be more ballsy and drive in harder with just my rear disc] and a couple of 125cc shifters. Really doesn't make a lot of sense for me to move up to a more powerful engine if I'm already outrunning them, in fact, when I borrow a faster kart, I just lap more people instead of pulling out to a straight-away advantage. I miss the track time, but my car is on it's way to being very, very fun.