I have 3 saws with scored cylinders. 2 Husky 346xp(s') and an 024av. I blame my father in law for the Huskys. One is (was) his which has gone through two pistons and now the jug is killed. The other is mine, which I bought because I liked his. I lent it to him last month because his stopped running and now mine has low compression. I watched him running mine and he's bogging the saws down to the point that chain just stops and the saw is at full throttle. And he doesn't let up. A couple times I saw him running the saw just above the rpm that the clutch would start slipping. Made me sick! The 024, I don't know anything about. My step dad bought it for $25 and it had been sitting a while, judging by the fuel in it. The muffler screws were rattling around inside the muffler so I took it off to look. The piston is scratched up bad. I got it to run but it was bogging so I took the carb off. That side of the piston is just as bad. What are the causes and how can you prevent this? I can rattle off a few but I want to hear from the guys in the know.