1987 Evinrude XP 150 Lower Unit Oil Emulsified, Where to look for leak?

[joshua27]

Got a new to me fish n ski last week. Got around today to changing out the lower unit oil and it came out completely emulsified. Oil is gray and thick. I'm assuming it hasn't been changed in quite some time and has had a steady source of water intrusion.

This is my first time dealing with a leaky lower unit, what is the most likely culprit and where to start my search for the leak?

 

[flyingscott]

Probably do a pressure test preferable or make sure both screws have the gaskets on them and run it. If it has water in it in a couple days needs to be resealed.

 

[emdsapmgr]

A marine dealership will perform two tests on the lower unit. A pressure test and a vacuum test. The lower unit needs to hold vacuum and pressure (without leaking down) for a set period of time. (maybe 15-30 minutes.) If you get evidence of a leakdown of any amount, the lower unit needs to be resealed. A factory seal kit will come with all the parts that need to be replaced: carrier o-ring, dual prop shaft seals, upper drive shaft seal, shift rod housing gasket, shift rod o-ring. 4 replacement carrier housing bolts/orings.