What model saws? I am assuming the carbs on them have both high and low adjustable jets. The "burble" might be it "4 stroking" in which case yes it is too rich. probably need to turn the H needle ( the one furthest away from the cylinder) in just a little.. start with 1/8 turns....You do not want it 4 stroking while in the cut. Ideally. you want to adjust it so that it cleans up in the cut, but if you lift up on it, it will start to burble, but then clean up again when put back in the cut... at least that is the way I do it.. that way it gives you the most fuel without being too rich..and fuel helps lube and cool the engine so I like to keep as much as I can moving through it..
As for the idle.. that would be the L jet.. (one closest to the cylinder) if you are having to ease into it to get it too open, it sounds like fuel might be pooling in the crancase and when you open the throttle it is slightly flooding the cylinder.. try leaning it out just a hair and see if that helps..
As the weather gets colder, I had to re tweak my saws the other week when I used them...Generally cold air is denser and thus requires more fuel to compensate for it...but it can also be related to humidity or air pressure which change daily so.....