I've had a spatchcock turkey on my UDS for 4 1/2 hrs and barley made the 4/140* treshold Smoker at 250-260* for 1st 3 hrs, then jumped to 300* - 74* outside, strong wind (windsceen in place), 10 lb bird. Why the slow increase in internal temps? Does location of vent have a bearing - over bird vs other side of smoker? Help apprecated....