1988 Sea Ray with 260 hp Mercruiser 350 GM 5.7L eng. Trim system has an Oildyne/Singer pump. Boat has been winterized and sitting all winter. Just got it out and started engine and ran trim down. As I ran the trim down, the oil was spewing up through the plastic resrvoir cap (has vent hole in it) thru the vent hole. Was able to trim it up and down a little and could get it lower before oil would start backing up and spewing out the vent hole, but have not got it all the way down yet. Does anyone know what this indicates or where to look for the problem? Also, oil has not been changed for a long time. It has a milky, gray color to it.