Combine first 6 ingredients in a saucepan. Bring to a boil, stirring frequently; reduce heat, and simmer 2 minutes. Remove from heat, and set aside.
Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Place chicken on rack; grill, covered, 5 minutes, turning frequently. Brush chicken with catsup mixture. Grill an additional 12 minutes or until done, turning and basting frequently with remaining catsup mixture. Transfer to a large serving platter.