I have an 042 Stihl that is a dandy old saw when it runs .Every time I use that frustrating SOB it needs a rebuild on the carb and I've always ran it dry .
That thing pizzed me off to the point I nearly flung it under one of my dozers and flattened that thing like a pancake but I refrained .After I get over my mad-on ,which has been several years at this point ,I'm going to once again make love to that fickle carb and leave the gas in it to run a little test .
I don't know the answer .Big Dave N ,who has been around saws since Shep was a pup never even drained his race saws back in the day .Poured to old gas out come spring time and ran the midwest circuit .