I had two carts when I was a teenager, both bought second hand myself.
One had twin Macs and was fast has heck. It was a true racing cart, but the brakes didn't work (missing parts), so I would stick my hand over the carbs one at a time to kill the motors and they had so much compression it would stop pretty quickly.
Never really got to take them to an official track though, just ran them around the neighborhood. My buddy ran the fast one into a head stone at the cemetery and bent the crap out of the front end.
Always wanted to do the racing gig with my grandsons, but they are just too far away.