In a saucepan, soak the salt cod in water for at least 24 hours. Change water a few times.
Boil potatoes with skins on for 30-40 minutes. Remove from pot, let them cool, then peel. Mash potatoes with a masher or grater. (Food processor makes them too "whipped").
Drain and rinse cod. Return to saucepan of boiling water. Lower heat to medium and cook 8 minutes. Drain and let cool a little. Remove skin and any bones. In a food processor, finely chop onion and parsley and transfer to a large bowl. Put cod in the food processor and pulse to shred fish into fine pieces. Add to same bowl as onions and parsley.
Add potatoes and eggs to bowl with cod, onion, parsley, and combine everything. Using 2 tablespoons or wet hands, shape bolinhos into little torpedoes or balls. There should be around 40 when done.
Heat oil in pot (or deep fryer) to 375°F (190°C). Fry in uncrowded batches, turning, until golden brown, about 4 minutes total. Drain on paper towels and serve with lemon wedges and a yogurt dipping sauce.