I was coming home from Micky D's yesterday morning, and I saw a guy at a yard sale with a red bike...and mounted in it was the biggest blackest engine I'd seen. Obviously not a happy time. So I pulled over and chatted with him about it (I'm sure he was use to it). Turns out it was a 5HP engine from a garden tiller he'd had. And it was a pull start, and he had it on a belt drive setup.
Very cool. He said his top speed was 25~30mph, and he hadn't calculated his MPG yet. I showed him my motorized bicycle and mentioned these forums, but he didn't look like the kind of guy who even owned a computer. Old farmer brown type. Overalls, missing tooth, you know, the Arkansas works!