I am new to this page and im wondering what to do with my yz 80. I have a 1993 yz80 with a big bore. Last week I was riding it, and the engine locked up. So I tore it down and figured my conecting rod bearings were bad, and the con rod is hitting the bottom of the case. I was trying to sell it before and know the value of an 80 is around 600. So im wondering should i rebuild the bottom end, sell as is, part it out, or put an engine that wasnt meant for this frame. I've also found a yz 80 engine on ebay for $135. And if i were to rebuild what tools would I need. Ive done alot of top end rebuilds before, but not bottom end. I believe i need a tool to pull apart the case but I am not sure. Any help or thoughts is much appreciated.