My 254XP lacked compression and the piston wasn't scored.
It turned out that one of the bearings (pin bearing) came out of where the connecting rod is attached to the crank and came up through the cylinder. It didn't damage the piston or cylider sides. (just the top) It gave enough play in the rod to oval the cylinder and lose compression. In the end the saw wouldn't start.
Ariens 11528 snowthrower, Craftsman 18hp lawn tractor, Craftsman 5hp lawn mower, Craftsman 4.25hp pressure washer, Stihl BG55 leaf blower and vac, Stihl SH26 string trimmer, Husqvarna 365 special Chainsaw, Husqvarna 254XP chainsaw.