Being in Michigan you have a ton of good vintage minis to choose from. The Chinese bikes are terribly built and even putting another engine in it will be too much work for the end result. They break with much more power on the frames, a member a couple years ago spent more money and time on one trying to beef up the frame and other components he ended up buried financially in a cobbled together mess. Buy a $100 roller and put a good engine in it, hard to have regrets when you start with good and end up even better.
outlaw I would have paid $100 for a roller...they were $300 and up....too deep for my pockets...believe it or not it starts right up..the one thing i like about the bike is that it has the wire harness for the lights, turn signal, horn, etc.. just a 2nd bike to play with...ill save the engine i have for my 3rd bike with a better frame... thanks for the advise....im a newbie that is now hooked on minis..