I just moved about 5 months ago and my property is all oaks and beech trees. There are some downed trees that the previous owners didn't bother to cut up / harvest for firewood. I've been using my brother's Husqvarna 445 with a 16" bar to fell and buck some fresh and standing dead trees as well as buck the downed trees. I'm considering an MS 261 or a 550 XP, but for now his 445 will do. I started with a new .325 chain and it seemed to cut well but after shapening the chain a couple of times, it seems to have a tough time cutting some of the downed trees. It smokes quite a bit and the bar looks to be blued at the edges as well as has most of the paint removed. I know that if my chain sharpening is not correct it can cause the chain to run off line, and dull quickly. Also causing it to run hot and smoke. After experiencing the issue, I've re-filed the chain to try to correct my poor filing and the cut. I haven't tried flipping the bar but I will the next time I cut. However I did try cutting from the bottom of the wood (top side of the bar/chain) and it cuts much better and straight. Still smokes though, and I always make sure the bar oil is full and that it is getting on the chain. So I'm confused, wouldn't cutting from the bottom of the wood (top side of the bar/chain) be the same as flipping the bar and cutting down through the wood? Also while I'm at it - my local Stihl dealer is telling me to steer clear of the M-tronic because of repair issues. For those of you who run an MS 261 or a 550 XP, what is you experience with the M-tronic / Auto-tune versus non? Thanks in advance for any insight you might provide.