I was just trying to get a handle on whats out there In the way of high performance small motors and I came across this site. Pocket bike 47cc racing motor 2 stroke 10000 rpm. Has anyone done anything with one of these?
I think at least one person has fitted up a piped version of one of these to a bike... they are fairly powerful for this application though.
My bike runs a 32cc engine with a pipe and tops out at 35mph - easily cruises at 30mph - some have had bikes up to 55mph and one electric made a recorded 57mph
If your not familiar with MB's it might be worth going with something a little less powerful first and then upgrading as and when..