Seals replaced...
I managed to fashion my own "tool" using a Dremel wrench, vice grips & a screwdriver as a fulcrum. Seals replaced, just in time for Irene. I tested the saw for about ten minutes cutting a 20" diameter red Oak log. Saw was running rather rich when I first started it then it leaned out after it warmed up in the cut. Max RPM was around 13600 - 13700, so it may be fixed but need more testing. I had checked the impulse line, fuel line & manifold but could not find a leak so rather than test the seal I just replaced them. It's a pot shot so I shall see.
Should the saw start rich (4-cycling) & then lean out when warm? I expect to adjust the carb when I use the saw after our storm. If this saw still climbs to 14500 RPM or more after warming up & cant be richened up then I guess I will have to test everything including the case.
I found this kind of hard to diagnose for me. The saw would idle fine, rev fine but once it got warm or hot the saw would achieve 14500 RPM wide open with a 20" bar. Richening the high speed would have little effect. I assumed a leak and after checking the lines took a chance that it was a crank seal leaking when the heat expanded it. Does this make sense to any of you more experienced here? Can you see any other source that would allow the engine to rev too high after it has been warmed up?
I appreciate all of your help!!