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Having read the posts below, I think you had the burgers on the fire too long at too low a temperature. Run your dome temp up to 600F to 650F. I use about 15% fat content in ground chuck. Make your patties about 5/8 to 3/4 inch thick. I like my burgers a bit rare so I only cook them for 3 minutes a side. If you like them more done, try between 3 1/2 and 4 minutes a side. At those temps and for that short a time you won't get too much smoke taste.