I have a ~10 year old Stihl 036 saw that I can't get started. It's in great shape and hasnt been run much especially in the past few years (probably the source of the problems). It had been sitting for ~2 years so I drained the old gas, put in fresh 50:1 gas with Stihl oil, put a new plug in, and tried to fire it up. Choke doesn't seem to matter... won't start at any setting. Pulled the plug out and it's sparking, so I'm assuming its a fuel problem somewhere. There is definitely fuel getting in though, because the plug is wet when I pull it. Also, it alternates between pulling smoothly when you tug the cord and sorta resisting as if the engine is seized. Can't figure out why it would go back and forth though... Any advice?