Nissan NSF5B 1985. Need Help!

I just bought a 1985 NSF5B. Seems to start up fine. I just need to work on the carb needles.

I do have a question thought. I hope I can explain this without pics, if not I will have to post some. When I placed the motor in the test tank it seems to discharge a brownish lube/oil, not sure if this was gear oil or not. I checked for cracks in the lower unit and could not find any. Seems this oil is coming from to small ports in the front of the shaft. The ports are just above the hex bolt on the lower unit.

After I took it out of the water I wiped away the oil, it seems to be seeping out of these ports, it did end up stopping and seems not to be leaking anymore. Is there a gasket I need to replace? The exploded view of the lower unit does not show one.

Looks like a clean and well kept motor/low hours, and I assume it sat for awhile. Hope I didn't bite the big one on this. I spent $400.00, which I though was reasonable.

Please help thanks. Any other suggestions are appreciated. I was thinking of swapping out the steel tank for a plastic one, any thoughts?

You probably have an NS5B, not an NSF series. So that would be a 2-stroke. What you are seeing is unburned fuel/oil residue, and is normal. If the old steel tank is still OK, that's fine. If it has even a hint of rust, it's time for a new plastic one.

Thanks Paul. Is it still normal to find it collecting on the hex bolt by the prop also. Also seems to be seeping from the diaphram above the cavitation plate.

Diaphragm? That's one I haven't seen.

Yes, the entire interior of the exhaust housing can get coated with that gunk over time. As long as the LU lube is at the correct level, it isn't coming from there.