Trim fat from pork roast. Place pork in a large heavy-duty, zip-top plastic bag.
Combine lime juice, orange juice, brown sugar, onion powder, ground allspice, dried thyme, red pepper, ground cinnamon, clove garlic; pour over pork. Seal bag; turn bag to coat pork. Marinate in refrigerator for 8 hours, turning bag occasionally.
Preheat oven to 350 degrees F.
Line a large roasting pan with aluminum foil, and coat with cooking spray. Remove pork from marinade, reserving marinade, and place pork in prepared pan.
Insert a meat thermometer in thickest part of pork, if desired. Spoon reserved marinade evenly over pork.
Bake, uncovered, for 1 hour and 30 minutes or until thermometer registers 160 degrees F, basting occasionally with juices.
Cover with aluminum foil, and let stand 10 minutes before slicing.