On junk that's hardened onto my bars, I've used a bit of turpentine. I scrub it, if needed, and after the turpentine has softened it a bit, with one of those plastic dishwashing scrubber pads. I have also gently used a putty knife to loosen extra-tough stuff.
On the plastic and metal body parts, after getting advice here on the forum, I've begun using Simple Green. Again, sometimes the plastic scrubber is needed. I rinse with water [I use a spray bottle]. I do this out in the sun, let it all dry and am careful not to get anything into the muffler, etc.
So far, these two methods are cleaning up 98% of the gunk. Once cleaned up, I have found that I can clean up new stuff quickly if I just do it every few tanks of gas. I mean to, but then I sometimes just don't get to it. On your old saws, where stuff may've been hardened on for years, might take you a number of times resoaking and scrubbing off a bit at a time. That was the case for me on one saw. Must've taken me four or five hours on that one.
