Place chicken in dish large enough to hold it all in one layer. Break thyme sprigs in half and ruise them. Scatter over chicken with garlic. Toss with olive oil, lemon juice and black pepper. Cover and marinate in refrigerator for 6-8 hours. Turning 3-4 times.
Prior to cooking brush marinade off chicken. Grill over medium hot coals (or in broiler) for about 10 minutes. Turn frequently and sprinkle with a little salt when almost done.