Prepare charcoal coals for grill, or preheat broiler. In a small bowl, mix orange juice concentrate, maple syrup, rosemary, 1/2 teaspoon salt and 1/2 teaspoon pepper. Place chicken and potatoes on the grill or on a sheetpan under broiler. Sprinkle with 1/2 teaspoon salt and 1/2 teaspoon pepper. Grill or broil chicken and potatoes for 25 minutes, turning all pieces at least once. Brush chicken and potatoes with one half of orange juice mixture, let cook 30 seconds and turn. Brush second side, cook one minute and turn all pieces again. Cook for one more minute. Remove from heat and serve.