Combine first 8 ingredients in a bowl, stirring well with a whisk. Combine 2 cups orange mixture and pork in a zip-top plastic bag; seal. (Reserve remaining orange mixture for another use.) Marinate pork in refrigerator 8 hours, turning bag occasionally.
Preheat oven to 350º.
Remove pork from bag, reserving marinade. Place marinade in a large saucepan; bring to a boil. Reduce heat; cook until reduced to 1 cup, stirring occasionally (about 20 minutes).
Place pork on a rack coated with cooking spray, and place rack in a shallow roasting pan. Sprinkle pork with salt. Bake pork at 350º for 1 hour, basting occasionally with reduced marinade.
Carefully pour 1/2 cup water into bottom of pan (do not remove pan from oven). Bake an additional 45 minutes or until a thermometer registers 160º (slightly pink), basting occasionally with marinade.
Discard remaining marinade. Remove pork from oven. Cover with foil, and let stand for 10 minutes before slicing.