I had one of my 350 husky saws have a sticky compression valve. With low compression. Not thinking too much into it I just replaced it and moved on. Now a jonsered 910e had a carboned up compression valve into the port. I have no clue as to what brand of two stroke oil they were using nor what ratio. I dug outvthe carbon with a small screwdriver. I’m thinking about grinding a tap drill flat to clean out the bottom of the treaded hole before replacing the compression valve. Now I wonder how many of us experience low compression when it’s the compression valve leaking? I was just wondering how common this is. Do I need to change out the compression valves in all my used saws.?