Govenors dont normaly become unadjusted.
agree totally!
Although, if the initial setup is wrong it could be "out of adjustment".
The governor spring attaches to a fixed tab setting the tension for the governor. If it got bumped, it could cause the symptoms you are having.
Often times bending the tab VERY slightly will resolve the pulsations. I've seen a little as 1/32" change to completely clear the issue.
The newer 4 stroke carbs don't seem to be as problematic as the older 2 strokers when it come to old fuel.
My 11.5 HP 28" Craftsman sat all summer with old fuel and starts on the first pull. I don't even need to use the electric start........lol
Heck, my 1979 Toro sat with pre-mix all summer and starts right up.
Then my other Craftsman 5/22 had a big issue last year similar to you.
I cleaned and rebuilt the carb with all new parts and it still would not adjust right. Then I remembered I had put in a new oring for the needle adjust. Having experienced this problem on Toro's in the past I recovered the old ring and installed it. Bingo! It now adjusts perfectly.
As it turns out, the original ring does not have a round profile. It is more like square shape with a taper ring. All of the replacements from Craftsman, Briggs, and Tecumseh are a round profile and in
some cases do not work. I've ordered them from all 3 sources and from my local dealer. I shared this with my Toro dealer and he was able to resolve a few difficult machines at his dealership. We tried changing the needle, needle spring and washer with no effect. I now save all the old ones just in case.
I just hope this helps someone else....