hey, sounds like the cylinder compression is down , play in the bearings is quiet normal for these engines wont do any damage , because there is fuel getting to the cylinder i still say the crankcase is fine, especially since you found no compression in the cylinder, so i guess its barrel off again. also conrod play is also normal. im thinking that the clearance between the cylinder and the piston is excessive and the rings are failing to seal the gap. dont reach for a drum of fuel and matches yet.
