Originally Posted by scottIN

Dude. You in no way need that size of an engine. Or that much weight. My kart weighs about 175 lbs. and with a 125cc (26 hp) engine will do 75. Shifter karts with a 250cc moto engine (42 hp) are pretty much uncontrollable. 0-60 in less than 2 seconds.

The engine is the easy part. The chassis / ackerman, etc. is the hard part. Becasue a kart is direct drive, solid axle, the chassis has to be able to twist to lift the inside rear wheel off the ground to turn it. If not, you're stuck going straight (or will overload / bog the engine with every turn).