Oil leak after changing impeller

[Nathan81832]

I’ve owned a 2008 90tlr two stroke for a year and a half and figured it would be a good idea to change water pump. I ordered the Yamaha kit and watched some videos and it seemed fairly straightforward.
I should mention that the motor had been running great up to this point
i removed the lower unit, and replaced the water pump and seals just as videos showed. I noticed that the damper seal and damper seal ledge were so worn and corroded that there was hardly much of either remaining. I pulled both parts out and cleaned the area really well, and forgot to replace when reinstalling the LU.
I also figured this was a good time to change lower unit lube, so i drained and pumped in new Yamaha lube.

When all out back together, I attached muffs and ran motor and all seemed well

fasf forward a couple weeks later and I launched the boat, fired it up, and it didn’t take long to see that I had oil leaking from the motor. Motor seemed to run just fine, but there was a milky, foamy mix coming from below the cowing and top of the shaft.

I figured it was a leak from the oil tank, but upon inspection, I didn’t notice any oil under the cowling.

Could I be leaking lower unit oil from that high up? Does the missing damper seal have something to do with it?

or is there something else that I may have messed up while changing water pump that could lead to oil leaking from this location?

[Nathan81832]

[Nathan81832]

I believe these are the two parts that I failed to replace and will be ordering now. Could this be the cause of the leak?

[rodbolt17]

the damper seal has nothing to do with any leakage.
insert the knife between the second and third rib.

[99yam40]

that seal keeps exhaust gases from getting into the water pump.
maybe exhaust gases are pushing water up and out that opening, but I do not see how it would cause oil from anything to leak

[Nathan81832]

Ok I was sort of hoping that could have been the problem. Any other suggestions on what could cause a leak as in the pictures?

i loosened the lower screw in lower unit and let out a little oil and it looks as clean and clear as when pumped in which makes me think that it’s not lower unit oil or it would have looked cloudy. Unless lower unit oil is going out but not letting water in

i did did not see any oil pooling under the carbs or block

any other places it could be coming from?

[panasonic]

Looks like emulsified lower unit oil to me. You filled the LU to proper level...never over filled it by chance?

[99yam40]

what does it smell like?
lower unit lube is some stinky stuff.

My guess would be unburned 2 stroke oil going out the exhaust or running down the drive shaft mixing with water and the exhaust leak by the dampener causing it to blow out the top. Kind of far fetched tho

[Nathan81832]

I don’t think I’ve overfilled lower unit. I pumped it in the bottom hole until I saw it seeping out the top, then sealed them both.

[Nathan81832]

It did have a yellowish tint to it which looks a lot more like the bright yellow lower unit oil than the dark two stroke oil