My son, last summer, decided to build his own motorbike...he took one of his old bikes and welded a bracket (with dad's help) onto it to hold a motor from an old gas leaf blower...viola, it worked...

He finally got a mini-bike, but this was a fun project. He's into mechanical stuff like that...just found this pic and thought I'd post it. He was 12 at the time.

Boy Genious! 🙂 Looks like fun.