Read Aaron's last post in this 8500 thread. https://chainsawrepair.createaforum.com/poulan/poulan-8500-pro/
Just in case a gov problem. Because I have seen Gov go bad on other saws. Had a Partner do sort of what OP describes.
They can be blocked off easily on others carbs.
I dont know anything about the 5200 5400 8500 carb. Maybe Tim knows.
The 85cc saws have a Tillotson HL-176 with governor. The 4200's came with an HL-168, same carb, no governor. The governor on my 8500 was bad.
Not sure if it's in your links above but cut a 1/4" diameter piece if aluminum out of a pop or beer can with a paper hole punch and dropped it into the governor well. drop the copper gasket in and replace the governor brass plug. That will disable it so it doesn't dump fuel. If the governor is bad they generally can't be tuned and run like crap.
I've only found two bad ones in all the governed HL's I have so if they're working, I leave them alone. The brass plugs can be a pain to remove.