1980 80hp mariner lower unit oil seals - oil

[mcurcio1989]

I just got the motor running (carb issues) and after tuning it on the stand / hose the next morning I noticed some oil under the prop. I pulled the prop and the seals directly behind the prop on the shaft do not look to be leaking at all. However there was a lot of water / oily buildup in whole exhaust / lower unit housing. I changed the gear oil and didn't notice any water or low level but I really don't have a good gauge for the level. Is that normal from the exhaust?

Are there any seals on the back side or is that the only point that could leak. - I really don't think anything is leaking from the prop side of the shaft. I know there are some o rings in the back but those leaking seems unlikely.

The boat is in the water now and I am going to pull it out tonight and change the oil again to verify that it is oil from the exhaust but in the mean time I wanted to double check my thought process

 

[woodsyfeller]

Re: 1980 80hp mariner lower unit oil seals - oil

There is going to be oily build up in the exhaust due to it being a 2 stroke that has oil mixed in the gas. I would guess adjusting carbs may have made things a bit rich and a little more then normal oil build up will be present.

I would run it for a day and check the gear oil to see if there is any water intrusion. The gear oil will have a milky/cloudy appearance to it.

I think your on the right track.

 

[smittylv1]

Re: 1980 80hp mariner lower unit oil seals - oil

May be a normal situation....overly rich mixture....keep an eye on it.