Okay, i was thinking of buying this 1985 yz 80 for basically just another toy, something to mess around on ya know? I've got a good deal on it, but it's because the crank bearing is bad.....Would this be a bad idea? How much of a hassle is a crank bearing? I've done top end work before and im pretty mechanically inclined. But thats the only thing wrong with the bike...Any ideas\opinions?