I remember... maybe... watching this once at someone else's house, but perhaps not paying full attention. Of course, I was much younger then.
Now I look back on this as... well, a bit of harmless fun, though slow to start, got decent toward the end. It was fun seeing a younger Joey Pants with Anne Ramsey as his mom, and the kids, though annoying at first, became even somewhat charming after a while. The whole pirate thing was pretty fun, and--- by golly, they saved the family home from the evil rich folks. What more can you ask for from a mid-80s film? 4 stars.