My saw died and taking it apart the cylinder/piston were scored. I bought a new cylinder housing and piston and put it back together, Ran through a gallon of gas and the piston scored again. The cylinder housing has no scratching but I did clean it out since it appeared there was some melted Aluminum from the piston toward the top. Bught a new piston and is running fine....

New impulse line

New Carb kit installed

New fuel line

New crank seals

New bearings

Used Si gasket for sealing in crank.

Using 40:1 mixture (definitely blue)

So I have not used it to cut yet since the underlying issue does not seem to be resolved. It idles fine and when I rev er up and adjust the high side carb screw I do not notice any change in RPM pitch... screw fully in our out and of course with the throttle fully open. The screw only travels 3/4 rotation. Is there something I am missing here?