1959 Johnson FD-13 18HP Lower Unit Leak

[ENCOUNTER91]

Hi all,

I recently purchased a 1959 Johnson FD-13 18HP. I’ve got the motor running after flushing the Gas lines, and it seems to be running fine. I noticed the rubber seals on top of the lower unit are worn, and this bluish-milky substance is seeking out while the motor runs.

After reading some separate threads I understand this is indicative of a water leak (creating the milky look), however I changed out the lower unit gear lube and the lube is clear white. The colour of the substance leaking resembles more of a gas/oil/water mix. I figure if it was a Lower unit gear oil leak it would be clearer in colour.

So, I am curious what this substance is? I have run the motor now on 5 separate occasions for approximately 2 hours total. The leak is not slowing down.

Any advise would be appreciated.

Thanks,

Nate

 

[F_R]

Is it foamy, coming from the exhaust? Cold lake water? Probably fuel/oil mix that has gone through the engine, done it's job, and discharged into the exhaust where it emulsifies with spent cooling water into a foamy goop. Some oils are worse about that, and temperature and running speed has a big effect. It's ugly but harmless unless you are worried about emissions into the lake. You can run Bio-degradable synthetic outboard oil if that is the case. I do.

 

[oldboat1]

Hi Nate. Welcome (Hope you have a good encounter...)!

First question is always whether it's fuel or gearcase oil. Does the fluid smell like gas or gear oil (sulphur odor)?

Are you saying the fresh gear oil is white, or the stuff you drained out was white? (coffee colored -- coffee with creme -- is usually the description for water in the gearcase). It's also possible to get almost clear water out of there -- not a good condition.

 

[Crosbyman]

gearcase lube should not be white ..did you use grease or gear oil ???


gas oil carbon junk from a 2 stroke is normal …

just check that gearcase...fill with 90 grade oil retest after s everal hours by dropping the oil in a jar let it settle 30 minutes see if you have water at the bottom of the jar… if yes then it is reseal time .

the rest is just goo or a leak (pin hole) in the exhaust cover plate . .

 

[ENCOUNTER91]

[No message]

 

[ENCOUNTER91]

Thanks Fellas,

I have attached two images of the colour. The motor runs fine otherwise so I think I am safe to assume it’a a fuel / oil mix (as it also smells as such ). I very much appreciate the quick responses. This Forum has a wealth of knowledge!

 

[F_R]

If you ran the motor for two hours with that much of a gear oil leak, there wouldn't be anything left in the gearcase but water.