I'm interested in learning engines. Enough so that I could fault-find most common problems, and repair them myself. Enough so that I could do most servicing myself (those not requiring computers and such anyway). I've always had an interest in engines, but I've never had a place to learn or an engine to work on 'myself'. I've heard from alot of people that 'working on one yourself' is the best way to learn, so my thought was to go out and buy a cheap, second-hand bike, that I can fiddle with and play on and rebuild the engine a few times without stressing over warranties, whether it's working, or anything like that. I have a new bike under warranty, and I don't really want to mess around with it now, because it's my primary mode of transportation, and I really can't afford to screw it up. So, I'm asking for opinions on whether I'm doing the 'right' thing, the 'wrong' thing, or if anyone has any advice or guidance or ideas that they think might help me. Thanks in advance.