I have a 50hp Yamaha outboard (1998) on a 26ft motor sailer. The hydraulic moter that raises and lowers the engine works only most of the time. Nearly always goes up. Sometimes does not go down even after trying many times. Usually it will go down the next day or so. I had it out of the water and a mechanic looked at it and found a little water inside. He concluded that was the problem and recomended not to buy a new one. He did his revision of the unit and re installed it. To protect it from water I put 3 coats of hull paint on the unit and then covered it with silicon and a neoprene cover that fitted snuggly over it.