Place yuca into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, 20 to 25 minutes. Drain.
Preheat an outdoor grill for medium heat and lightly oil the grate.
Combine corn, bell pepper, and onion in an aluminum pan. Add 1 tablespoon olive oil, or enough to coat the vegetables and the bottom of the pan. Cook on the grill, stirring every 5 minutes, until pepper is tender and onion is translucent, 10 to 20 minutes. Remove from heat.
Mash yuca and black beans together in a large bowl until smooth and well blended, adding about 1 tablespoon olive oil as needed. Add the grilled vegetables; mix well, kneading by hand if necessary.
Warm tortillas in the microwave, 30 seconds to 1 minute. Add equal amounts of the yuca mixture to the tortillas. Fold each taco in half over the filling and secure with a toothpick. Paint the top of each tortilla with remaining olive oil.
Place the tacos on a grill topper. Grill for about 5 minutes. Remove from heat and remove the toothpicks.
