Preheat oven to 350°F (175°C).

Drain lima beans, butter beans, red kidney beans, and green beans.

Combine drained beans with pork and beans in a large casserole dish.

Rinse the pork and beans can with 1/2 cup of water and add to the casserole.

In a separate bowl, mix brown sugar, mustard, and vinegar until well combined.

Pour the brown sugar mixture over the beans in the casserole dish.

Top the bean mixture with chopped raw bacon.

Separate the onion into rings and arrange them on top of the bacon.

Bake in the preheated oven for 1 1/2 hours.

Serve hot or cold.