Can You Build a 20-30mph Motorized Longboard?

[BigFly]

After seeing some people with these motorized skateboards i kind of wanted to try and make one. Does anyone know the best types of motors electric/gas? I would prefer an electric one but I am not sure if i could get it too fast with an electric. Well first off what are the advantages of electric over gas, and vice versa. Secondly does anyone know how to make either a strong electric or gas motor? is it possible to get this board up too 20-30mph?

 

[n1ftyneil]

Take an old jetski apart ;-) Mount it on the bottom and build a hand, trigger throttle.