1. Sort and wash beans; place in a large bowl. Cover with water to 2 inches above beans; cover and let stand 8 hours or overnight. Drain beans.
2. Preheat oven to 325°.
3. Heat a Dutch oven over medium-high heat. Coat pan with cooking spray. Add onion and pork to pan; sauté 5 minutes. Add beans, 5 1/2 cups water, 1/2 cup syrup, mustard, salt, and pepper sauce; bring to a boil. Cover and bake at 325° for 2 1/2 hours or until beans are tender, stirring occasionally. Uncover and bake an additional 30 minutes or until mixture begins to thicken. Stir in remaining 1/4 cup syrup.