Stihl 360 pro shutting off in cut

[crappiemiser]

Hello-
I was cutting with a friend yesterday and we were cutting up some big oak. His saw is a 360 pro with a 20" bar and after cutting for about 5 minutes his saw shut off and wouldn't restart right away but would after it sat in the 15 degree weather for a while. I pulled the muffler when we get back to my house and noticed the piston has some scoring. My first thought was the ignition coil, but after seeing the piston I am wondering if the saw is toast?

 

[pioneerguy600]

The piston is toast, the cylinder can probably be saved with some cleanup, new piston and rings. The saw should be Vac tested before tearing it down in case it has an air leak.