recommended electronics for a razor go kart

[BrianG]

I would say to definitely get an outrunner. The lower total rpm means less gearing down is necessary, and if you get something like this, you'll definitely have power if you decide to go faster down the road. For the ESC, I'd take a look at an CC HV ICE ESC. You can run ~6s for now, and then 10-12s in the future.