I just bought a 1979 deck boat with 185 hp OMC (I/O)--800 series Stringer. I had my "boat guy" look it over before I dropped it in the water. He replaced the trim and tilt motor and gave it a tune up. He told me that the lower unit should either be up (trailering) or down (boating)--no in between, otherwise I will do serious damage inside. The lower unit moves very quickly to either position. Also, there is a second switch that lowers and raises the lower unit by 4 to 6 inches (I've never seen that before).<br /><br />So, I followed his advice. Living on a shallow lake, I quickly tore up my prop. Not only that, but I had no way to adjust the boat at higher speeds--the front end was perched too high.<br /><br />On my previous boat, I could adjust the trim and tilt accordingly.<br /><br />Am I doing something wrong? Thanks for the help!