Dissolve yeast, warm water, and 1 tablespoon sugar in a mixing bowl. Let stand 5 minutes.
Add remaining sugar, sweet potato, butter or margarine, salt, and slightly beaten eggs. Stir to mix well. Stir in 3 cups of flour. Turn out on a lightly floured surface. Knead 2 to 3 minutes, adding just enough of remaining flour to prevent sticking. Do not knead too heavily; when smooth, shape into a ball. Place in an oiled bowl, and turn to coat the surface. Cover, and let raise about 1 hour or longer.
Punch down, and allow dough to rest for 2 minutes. Divide into 16 to 20 balls, and place on a greased cookie sheet or in a 9x13 inch pan. Allow to rise until doubled.
Bake at 375 degrees F (190 degrees C) for 12 to 20 minutes. Serve warm.