I have an 06 gs500f that kinda missfires at idle, low rpms and sometimes dies when taking off.  It runs good after it atkes off with no other missfiring.  It has 3800 miles on it and I have only put 400 miles on it since I got it.

Without any other info I'd say it's time for new spark plugs.  It is also possible you have varnish forming in your idle jets, so it doesn't want to idle but it's ok when you open the throttle, then taking fuel from the mid-main and main jets.  Yeah, your carbs have three jets each.  I would dump some Gumout, Marvel Mystery Oil, or your favorite varnish dissolver in the tank, change the plugs, ride it a lot, and go from there.  Best of luck with your fine ride!