Preheat oven to 350 degree's. Cook potatoes according to package direction. Stir together cooked potatoes,cheese,1 cup sour cream,bacon,onion,salt and pepper. Warm tortillas, then spoon mixture in the center of each and roll burrito-style. Brush with butter and place seam side down on baking sheet.Brush with butter. Bake for 12 to 15 minutes, or until golden brown. Cool for 5 minute, cut diagonally into halves and serve with remaining sour cream.