DJ is absoloutly right.. The problem is in your top hat setting..
I open the top wide and open the guru damper all the way and even crack the bottom door a little when starting.. Once you have a little overshoot on the temperature , close the guru to about 1/2 or so and the bottom door completely closed..
The top hat should be almost tight. 1/8th of a turn can be enough..for a 250 degree cook Your experience may vary.. but not much.. I know it is hard to believe but the 10 cfm fan will supply the right air flow .smoke will pour out of the KK.. even the top.. Dennis says as well , adjust the top down till you can just feel heat coming out of it..