The worst thing you can do is just wait till you blow it. You run a big risk of crapping out your crank, bearings, whatever gear it was in when it locked up.....you get the picture. Get a compression tester, keep an eye on your jetting, a clymers will give you all the specifics as far as ring end gap, and when to inspect top end according to compression and such. A lot of time you can get away with a hone and a new set of rings if you just rebuild it when it is supposed to be, at very least, save on a new crank.