I have a 1983 Glastron with a 120 Mercruiser. I have found the bottom oil fill and have located a "oil vent" up high, above the steering pistons. I filled the lower hole with a squeeze tube (1 qt. bottle) but nothing came out the top vent hole. <br /><br />Newer Merc owners say their oil vent hole is no more than 10" from the bottom hole. <br />Do older Mercs have the vent higher or is there another vent hole closer to the bottom? <br /><br />Thanks, <br /><br />Barry