Yeah,i know that Mark.New carb,seals,lines,filters,tunning perfect,no dust inside the cylinder and after ~20 tanks,low compression.The cylinder isn't so bad,2-3 signs of wear.Same the piston.No scoring at all.My guess is that these cylinders are very low quality.The saw is running perfect as it is.Strong,cool,nice idle,all ok.The problem is that when it is hot and i try to restart it,it is impossible except if i pull the rope 15-20 times.