Just did one last Saturday, It takes 3-3 1/2 min lb cook the small one at 350 10-13lbs anything larger cook at 325. Mine was a 14 lber and done in 45 min.

Use an instant read thermometer and check it 15 min or so before it supposed to be done 180-190 in the thighs.

Chicken on the other hand takes longer I did one Sunday about an oven stuffer roaster about 5-6 lbs and it took 45 min. but mmmmm good.

You may want to cut as much fat off as you can (tail bone and inside flaps) . You can also boil it for 5-10 min to cut down on some of the fat and cooking time. I don't.

Also I prefer mine plain without marinades.
Good Luck and enjoy those leftovers.