Cut the chickens into legs, thighs, breasts, and wings and place in a large pan. Whisk together the remaining ingredients in a small bowl and pour over the chicken. Cover the chicken and refrigerate overnight.
Preheat the grill. Place the chicken pieces on the grill at a 45 degree angle to establish good grill marks. Once the chicken easily releases from the grill, turn it over to continue cooking. Make sure to season the chicken with salt while it's cooking. Once the internal temperature reaches 165 degrees F, or its juices run clear, remove the chicken from the grill. Let the chicken rest for 5 to 10 minutes before serving.