In a small skillet combine the oil, vinegar, salt and pepper and put over low heat. Add the poultry seasoning while stirring constantly; when sauce mixes well and starts to bubble, it is done.
Place chicken on hot grill and brush with sauce. Grill for 45 to 60 minutes, turning every 5 to 10 minutes, and brush chicken with sauce after each turning. Grill until chicken is done and juices run clear. (Note: Be sure to keep an eye on the chicken as it cooks, as it tends to have flair ups due to the oil and chicken drippings!)