it ran as smooth as can be when I bought it. When i first purchased the boat, i heard the knock but it was initially a very quiet noise and i just figured it was regular noise from the motor. It has now rapidly become super loud. The engine doesn't run particularly rough, but it definately doesnt run as smooth as it should or did, and is steadily getting progressively worse. Not happy with it, but hopefully I will have it completed before the fall fishing has ended. I was really looking forward to fishing this fall .