The engine is a 125cc Yamaha dirt bike engine from some time in the 70′s or 80′s and there is an exhaust pipe but it doesn’t do very much at all.

i have a go cart that is a 2 wheel drive (rear wheels) it is built very sturdy and has suspension. i would like to know if it would be possible to put any kind of small dirt bike engine on it (50-150cc) and if so how hard would it be to hook up and mount.