Spraying Seafoam directly into Honda 2000 Carb.

Unless you have a bunch of grime inside the carburetor throat, it is a waste of Sea Foam. Surging or poor idling is usually a clogged main jet. The best solution is to tear down the carb and clean the jets and orifices. You could also wait to see if the Sea Foam clears the obstruction in the jet but sometimes it will not dissolve whatever is clogged in the jet.