The motor was rebuilt before I bought it, when it first started with this problem we changed all the fluids, and noticed that the oil filter was in backwards.  There was no oil the lower end, but the reservoir tank was full.  Do you think this may be the crank barring's or the rings?  Where should I start?


It starts up fine when it's cold but once it gets hot it locks up and shuts down.  If you put it in gear you can rock it backwards to free up the motor, then it will start back up for a few seconds, then lock up again.  Any help or advice would greatly be appreciated, thanks in advance.  

Best way i could tell ya is to pop the head off and check the sleeve.if its warped or torn up looking this could be the problem. when the bottom end usually goes bad it just goes and freezes up solid.id check this first as the guy who rebuilt it may have not done the job right and it just lasted till it did by luck and grinding.