I read on the forum sometime ago about an excellent fuel additive that would in most cases dissolve gum.
I am working with a friend who has a portable generator who closed the shut off valve and ran the fuel from the carb six months ago. Now with fresh fuel in tank, the engine starts and goes to hi governed rpm but shuts off when auto idle switch is activated. Since everything worked when he stored it, I suspect that the low sp jet has gummed.
I am working with this friend over email and have no idea what carb he has, but he sees no external adjustments, figure the jets are fixed.
I think 30 yr tech may have mentioned this product several months ago.
Name of product and source please. Tom

Sea Foam is an excellent fuel additive. Most auto parts stores have it. I know Advance Auto has it.

Sea Foam is an excellent fuel additive. Most auto parts stores have it. I know Advance Auto has it.

This is most likely what I recommended, as I use Sea foam additives, and it's available at most auto parts outlets, I think I have seen it in Wally World as well.

If you can't find Sea Foam, Chevron Techron is also a good product. Have a good one. Geo