Combine beans and water in a large kettle. Bring to boiling; cover; cook 2 minutes.
Remove from heat and let stand 1 hour then pour into slow cooker.
Brown salt pork in a large skillet; remove with a slotted spoon to slow cooker.
Sauté onion, garlic and green pepper in pan drippings; remove with slotted spoon to slow cooker.
Brown beef, a few pieces at a time in pan drippings; remove to slow cooker with slotted spoon; stir in salt, oregano, red pepper, cumin and tomato sauce. Add more water, if necessary to bring liquid level above beans.
Cook on LOW for 10 hours or on HIGH for 6 hours, or until beans are tender.