Re: 73 Johnson 50hp water in lower unit?
The first thing I would do is drain the lower unit oil and replace it with compatible oil that has a moisture inhibitor mixed in with it. I have never changed the prop seals, so I don't know how difficult or expensive it would be.
On the other hand, I have run many lower units that have leaks I would just check it before each use. I would keep LU oil on hand and a pump handy. Before each use, I would top the LU off with fresh oil. Most of the time I would pump extra oil in, pushing a lot of the milky oil out. Water will be in the gear case, but unless the leak is severe, to the point where you are losing a significant amount of oil every time you take your boat out, you should be fine. Also, check eBay for a new lower, because yours may not last long. I emphasize the word may, because I have seen LU's last for years with leaks.
The thing with these old engines, is that it costs a lot of $ to fix them. Especially when you talk about a major overhaul, like taking apart a LU to change seals. It becomes more expensive than what it's worth. You never know what the mechanic will tell you, he may say you need all new bearings and gears. I would never have a LU of that age rebuilt, unless I totally trusted the mechanic, ex. a relative, etc. Even then, I would look for a used one on eBay, preferably from a seller with A+ feedback and a high score.
I know that all of you old pro's out there will disagree with running a LU that has milky oil, but remember, the thing is 35 yrs old. How much money should you put into a 35 yr old gas hogging engine that will most likely develop another problem before the year is out?
My advice is to keep it running with the least amount of $ possible.
