Jokester's right, pick up a good STIHL or Husky. I am only a DIY'er, but my little STIHL MS170 cuts way above its pay grade, runs 12-18 inch bar, I run a 16 inch. On the 18-inch bar, you wanna up the chain size, I have heard. New 2-strokes don't have a lot of smoke when used with a quality oil. I have rarely seen smoke out of mine, running 50/1 mixlumber. custom milling.