YouTube go-cart creator makes 8-wheeled, 6-wheel drive, dual 301cc single-cylinder gas engine go-cart.

The engines are two Predator 301cc gas motors. Each offers a whopping eight horsepower, meaning this cart is putting down 16 ponies to those six driven wheels.
The go-kart actually started life as only a 6x6, but the builder couldn't get the brake-turning mechanism to work, so he just slapped on an extra set of tires and a front end from a go-kart so he could turn the thing. And it seems to work all right, as you can see from the handful of videos above that the machine scoots and will even drift on a lawn. 

https://www.rideapart.com/news/729710/twin-engine-8-wheel-6-wheel-drive-go-kart-video/