could be. hopefully, someone just didn't have the money for parts. make sure most of the parts are there, the engine isn't seized. being that they pulled the tensioner, it could be: stretched chain (most likely, behind bad plug/coil/cdi), sprocket came off of cam(not nearly as likely, but it does happen), chain jumped off of cam sprocket (almost never happens, due to the bike running like extreme crap if it will run at that point to begin with). could be the pervious owner wanted to familiarize themself with their ride (best case scenario, though about as likely as sprocket coming off cam)