Recently rebuilt the engine, finally got it running just had the cyl. bored and honed. Runs alright when its cold but still not 100% - The problem is when i start driving it -
Gets hot and will not roll over electric start does nothing and if i pull it by hand its almost impossible (but you can roll it over)
Cools down starts right up
I had to order the piston for the dealer and the only thing i can figure is they didn't measure it correctly
I remember the guy saying get a .2mm over and i ended up with a .25mm over but he wanted it to measure it but i know .5mm hot could lock it up basicly the dealer couldn't get a piston so i ordered it and shipped it right to them.

Question is before i tear it all apart again, could there be something else causing this to lock up when hot. It did run before the rebuild just poorly, but never locked up.

 

You probably checked but is it low on oil?