I think that you are experiancing "break-in problems" which would explain the changes in the settings. These engines take a little longer than most to seat the rings and loosen up to run really well. Carb settings are part of that and will eventually settle down, I just had to reset my G-90 as the idle increased beyond the ATV adjust on the transmitter, it has about 3/4 gal thru it so far and is just starting to run really well (have an OS 7m carb on it ) I rather think the carb is really not the problem for your engine if it's not fully run in.
I had a G-51 that took almost 2 gals. before it stabalized, it became a good reliable screamer...