problem after changing tanks

I have around a 2010 912ULS with 1,400 hrs that has been running exceptionally well.  I rebuilt the carbs last year and check the carb balance twice a year.  I just finished changing my wing tanks due to coating letting loose inside the tanks.  After changing the tanks the engine ran fine the first two times it was started.  The third time I ran it, it ran extremely rough as soon as it started.  When it starts, cylinder 1/3 have EGT's around 400 while cylinders 2/4 are in the normal range.  If I get the engine out of the idle circuit, above 3,200 RPM, it immediately smooths out and will not run rough even when the RPM's drop below 2,000.  I removed the float bowl and cleaned everything out, including removing the idle jet and cleaning it with a strand of 22 guage wire/carb cleaner.  I also checked all the wires going to the soft start module.  Before taking everything apart again does anyone have ideas what is causing this?