Well, she's all cleaned and back together now. I fired her up on Friday and she screamed like a banshee! Fired on the 2nd pull too.
So now that I have both saws, I can see some of the differences. The saw below has all metal cases, while the first one has plastic. This saw has 3 extra holes in the bottom of the exhaust chamber, plus an additional little screen down there. On the first saw, I think someone replaced the air filter cover with an earlier model maybe, although I'm not totally sure.
I ordered a few replacement parts off ebay just now. I also had to replace the cracked fuel vent line in this saw.
All in all, both saws are in excellent condition. It's hard to say which one I like more, although the second one (below) seems to rev better. However, that might be because I did a better job cleaning the screen on the exhaust port (plus the 3 extra holes). When I have time, I'm going to re-clean the screen on the first one and see if that makes any difference.
I also ordered new sprockets and air cleaners for both saws.
Interesting note: on this saw, I discovered someone had removed and improperly re-installed the carb. Not only was the fuel line routed incorrectly, but the throttle linkage was in the wrong hole and not allowing the saw to run at WOT.
I made a video of firing up the saw, but my daughter was screaming so much, I'm not sure which you can hear more
Ray