This past week I looked at a 1994 Liberator 201 with the King cobra 350. It looked pretty clean other than a few minor cosmetic flaws. It has been a lake boat since new with only one owner. The boat has been stored at a marina since new and the mechanic who has been working on it for the past 6 years showed it to me. He said the boat has hardly been used and has a very strong motor and out drive. My only concern was that while listening to it idle while on the trailer it sounded almost like it had a knock in the engine. The mechaninc told me that it was the flapper in the exhaust and the engine was fine. Does this sound right? Is there anything else I should know about these boats before going ahead and buying it?