I've never cleaned the exhaust screen on my 10-year old Stihl 025. I have always used Amsoil synthetic 2-stroke oil, but that saw has cut a lot of wood without the screen cleaning that is required in the maintenance book. The reason is, every time I think about cleaning it, I am about to go cutting, and if I break one of those studs, then it gets messy with drilling out high-carbon steel studs, easy-outs - you know the story. Do these things break when you attempt to remove the two nuts on the studs? If they do break, how much trouble replacing them?