Has anyone ever seen cycle kart racing?
https://youtu.be/T6C_EhgvuZA
Basicly you take a Honda GX 200 engine and build a replica of a pre war sports car.
The cost is below 2500.00 for the complete car. Most parts are from go carts and mopeds So it’s meant to be low budget. The emphasis is on creativity in building the car. And then it is about having fun riding it around with like minded people .
They have rally’s and Grand Prix events. Hill climbs you name it. It looks like a fun thing. And no you should not use a 250 ninja engine in one as they have one wheel drive and one wheel braking. No safety gear at all. That keeps weigh and cost down and because they are slow it’s relitivly safe.