Just out of curiousity, did you make a windscreen for you banjo burner? Mine has been doing insanely better since I made one. It seems like it was really effected by the wind and losing a lot of heat around the sides of the kettle. With the wind screen on, I had a rockin' boil in my converted keg with the burner on as low as it would go. Of course, that is less than half the size of your boil, but just thought I'd ask.