Trim fat from meat. Place meat in a 4- to 6-quart Dutch oven. Add enough water to cover ribs. Bring to boiling; reduce heat. Simmer, covered, for 1-1/2 to 2 hours or until meat is tender; drain.
For sauce, combine ketchup, chili sauce, molasses, lemon juice, mustard, and cayenne pepper. Place ribs on the unheated rack of a broiler pan. Brush with some of the sauce. Broil 4 to 5 inches from the heat for 10 to 15 minutes or until heated through, turning often and brushing with sauce. Heat any remaining sauce and pass with ribs.