Did you just wake up one day and say to yourself, 'I'm gonna build a motorized bicycle'?
Yes. Buddy of mine was into bikes when we were teens. He mentioned sticking a weedeater engine on a bicycle but never did it. I thought about it ever since, but never had the money when I had the time.
10 years later I was actually shopping around for weedeaters, but the engines all seemed puny. Then a guy on a Ford Festiva forum posted a link to this site and now I am hooked. It may be the death of me, and that'd be OK.