I am pretty sure my 78 gets richer with the screws turned out.
I have pods, free-flowing exhaust, and the bike wouldn't even start until I turned the screws out 4 times. By 5 or 6 turns I had a smooth idle at 1000 rpm. Another clue was that the bike was firing easy when I sprayed starter fluid in the air filters when the screws were closed; this isn't necessary when they are open. I went even further and once I got the bike idling I used a propane torch to spray gas in each air filter; When the screws are closed I get a surge in rpms, but when they are open the rpms do not move appreciably.
I can't be absolutely certain because I am flooding slightly at the moment, but when I turn them in--closing them more--while the bike is running my rpms shoot way up and the bike gets angry.
The problem is that running excessively rich or lean can sometimes produce the same symptoms. I won't know for sure what is going on until I adjust my float height.
I suggest starting at like 3 turns out and using the kick start so you don't kill the battery during the process. Won't start? Go another turn out and repeat. Once it starts running fine tune the screws. Once it has been running for a bit pull the plugs and take a gander. If it has black sooty carbon deposits or is wet with gasoline (not oil) it is running too rich. If it is running too lean they will probably be quite clean/white and may blister due to the overheating that tends to occur. Apparently they are supposed to look slightly yellow in color with no significant film or deposition.