This is my baja mini bike.I first bought a 212cc predator motor for it.Then i ordered a tav belt kit from gtc. I also put a cam with larger lobs to make it a little faster.A straight pipe.Aluminum fly wheel and 25 pound vavle springs inplace of 18 pound any questions just ask me. I clocked my baja out at 64mph with a real gun. These motors can do amazing things if you know what your doind.And they are so cheap for me i personally would take it over a dirtbike.