I have a 16 ft Harbor Craft and was have just put a new motor on it. The motor I selected, based on advice from friends, is a 4 stroke Yamaha F 50. The previous motor was a 4 stroke (American, made by Suzuki) Evenrude 40 HP. Except for trolling, it was a peach, quiet & ran all day on a tank but it has water in the crank case and is effectively dead. Even though the Yanaha has an extra 10 HP, it struggles (much more that the 40 HP Ev) to get the boat on plane. It has been suggested to me the Evenrude was over prop'd so had more ''poop'' out of the hole and that also contributed to the difficulty I had getting it to slow down for trolling. It DID have a bigger prop that the Yamaha has. I am very reluctant to change the prop on the Yamaha because it trolls beautifully; infinitely better than the old Ev. I am told a fin can be attached to the Yamaha that will lift the stern and put the boat on plane much quicker and once on plane, a small adjustment to motor trim will level the boat and improve fuel efficiency. Can someone recommend a fin for the Yamaha F 50. I have looked at the Permatrim hydrofoil fins, they are aluminum and look pretty nice (also available in ''made to fit'' for Yamaha but they are quite pricey compared to the others. Any suggestions, recommendations or comments would be appreciated. Many thanks! Twogone Cassidy BC