Hi there. Just wanted to post this up to find out if anyone has achieved this before. I'm running a 48cc bottom end and a so called 66cc head. I'm also running a standard carburetor with stock jets and venturies . My total milage thus far is over 1500 miles and I've tampered with a few exhauste systems as well. Recently I built (for the 1st time ever) a home made exhaust for it and I achieved 43mph. Aslo I'm running a standard CDi. I'd like to hear from one and all .