I sawed 2100 bf of lumber yesterday for a older guy, when I got done he asked me if I had any Stihl chainsaws (had my 520 with as usual) and what I thought of them. I told him they run good with my 170 being built cheap. He tells me he bought a new MS230 last year and it was losing power so he took it to 2 different Stihl dealers, both replace the spark plug, one was $50 the other $35 and the saw still didn't have any power when he got it home. He found the clogged muffler screen himself. Steve