I just got done making the basic bbq chicken recipe on the website. I put a whole chimney filled with briquettes, and half a chimney filled with briquettes on top of that. I had all three vents on the bottom open, as well as the top. I made three chickens. The entire recipe took 2 hours and thirty minutes to cook. Why did this differ so much from the recipe time? Does the 22 inch require more charcoals than those indicated on the recipes, since it is a bigger grill?