I've always heard that milky gear case oil means that you have water in your oil. This is not good ! Perhaps your o-ring between the prop and the gear case is in need of attention.
C.J.,<br /><br />Not good. <br /><br /> I would replace the O ring seals that go on the fill and drain screws first. They're cheap and easy, pick up some extras. They should be changed every time you remove either screw.
Milky or creamy appearing gear lube is usually caused by water intrusion into the gearcase due to one or more bad seals. You will need to replace the seals and pressure test the gearcase after the seals are replaced. I'm having the same problems with my old Evinrude 5.5hp. I replaced the propshaft seal and the gearcase gasket but it still gets water in and I'm going to have to replace the upper seals as well. Before you pull the gearcase and reseal it, try replacing the gaskets around the fill and vent screws and put some pipe thread seal tape on the threads. My Force 50hp had milky gear oil and the fill/vent screw gasket replacement took care of the problem.
