changed my outdrive oil on my 1988 aq211 with 290 outdrive, and i lifted it up and noticed a hydrolic cylinder inside housing, does this have a hydrolic tilt and can i use it when underway to trim boat? also there is a pump with seloniods mounted to the transom, also when tilted up the outdrive drops on its own, takes about an hour but what could be causing this, i have checked for leaks but cant find anything wet. i checked the manuel and they only talk about an electric tilt that cannot be used when underway, can someone explain this setup?