25 horse johnson 2 stroke leaking oil from water pump housing

[firstboat2015]

Hello, I recently received a boat and motor from my father. The motor is a 1969 Johnson 'Jet Power' 25 horse 2-stroke.

It runs really well, but after I ran it up I noticed globs of oil or grease in the water that I ran it in to test it.

It turns out that there was oil or grease (I'm really not sure which one) that was leaking out between the two pieces of metal that connect to surround the water pump.

It was pumping water just fine (I think, it came out of the exhaust and there doesn't seem to be a pisser).

If anyone could tell me where to start I would appreciate it. I'm trying to avoid a mechanic but might just take it in, I called one and he said it sounds like a bad 'base gasket', but I can't find this anywhere online.

The motor had a tune up about a year ago, runs fine, the impeller appears to be new. Something that seemed strange was that there was a fair amount of brown-tan grease/oil within this section of the motor that was coating everything. When I wiped it out and took apart the impeller housing there wasn't any of this inside so I'm not sure if its normal. Maybe it was river gunk from the water that runs through?

 

[Bosunsmate]

Have you checked the level of grease/oil in your lower unit?
Might be the seal under the water pump plate. Its only a few dollars

 

[firstboat2015]

So are you saying to check for some type of gasket that's under both the impeller blade and the metal plate that's under the impeller blade?

 

[daselbee]

Driveshaft seal. Common problem with all LUs.

EDIT: Sorry....just re-read your post. I question the DS seal diagnosis now.

Was this tan/brown oil and water sludge under the plate that the water pump sits atop?

If not, there is two stroke oil from the fuel coming from the powerhead area somewhere.
Could be lower crank seal, could be base gasket as suggested.

Eliminate the gearcase by pressure testing it.

No real way to eliminate the other causes except by disassembly and inspection.

A longshot could be a very bad running rich engine. That will make brown gunk on top of the tank,
but I never saw it inside the midsection before.

 

[firstboat2015]

It turns out that there was a remnant of a gasket under the water pump plate. My problem also appears to be from a bad upper and lower shaft seal. So needless to say I'm buying a repair manual so I can check anything that might need to be replaced.

Thanks for all the ideas.