Where do you live? I'm in SoCal and it's hard to find a used bike that I can buy, fix, and sell for any profit. I love working on bikes to, I've been parting out my old dirt bike that the motor blew on and it was more profitable to part it out then it was to fix it and sell it as a running bike.
I ride dirt bikes and race motocross. I also have a KTM Super Duke that I ride and commute with. I'm trying to find a way to make a business that has to do with my hobbies but not actually open a shop. On top of that, I trade stocks, futures, and options but nothing big, a couple grand to play with.