I got one of those saws too, about the same time as you. With factory presets for the oiler, it doesn't spit out much. Dealer says so long as over half the oil is gone when you fill up, you're doing ok. With regards to the black on your saw, only thing I can think of is it might be a bar issue (chain too tight). Think of aluminum when you rub on it (black). Just a thought, don't know if it helps. I have bar issues too, sprocket jams but the dealer says its because I'm cutting a lot of yellow birch (stringy fibers get under chain).