Is the oil port on the bar clogged? Is the oil pore on the body of the chainsaw clogged? If you have changed the sprocket lately there is an arm down in the circle for the sprocket that has to fit in a little slit on the sprocket itself for it to oil. There is an oil pickup body in the oil tank that I have read can get clogged, but I have never had that problem. At my main job the oil sits in the tank for long periods of time without getting used a whole lot and I have poured it out before and it has had little clumps in it, so I don't know if that applies to you, but it might. Hope some of this helps.
