Water in Oil

Recently, I found water in crank case. I took it to a mechanic I've used in the past, and the
results were....if he ran the engine in the tank....everything was fine...But....if he ran the engine with, "muffs".....
he got water in the oil. Any idea of.....what gives?? It's a 2006 BF50A
Thank you in advance,
TM2
*He put the engine under 50 lbs of pressure over the week-end, and it never lost an ounce...all gaskets were
tight and fine.

?---What part of the engine was under 50 PSI for the weekend.

Would love to know what the 50PSI test was as well. Can't even think what you could test like that other than maybe the water jacket but that would require heaps of work to block up all the various outlets. Not sure that I would want to test it at 50psi, but don't know what the normal water pressure would be so maybe this is OK. I guess you might try to pressure test the crankcase/sump, but 50psi on the sump gasket and rocker cover gasket sounds a bit dodgy, and then you have the normal leakage past the 3 sets or rings etc as well. Doesn't sound very realistic.
The place where you are most likely to get water in the oil from would be the head gasket I assume. Why that would change between muffs and a tank is a mystery unless the extra water pressure from the muffs is increasing the water pressure in the jacket somehow. Might be possible on a smaller engine like the 50 I guess. Maybe if you ran it at higher rpm's in the tank with the resulting increased jacket pressures you might get the same result? Best guess would be that you have corrosion in the head somewhere or if lucky just a head gasket issue.

My guess he is talking about the lower unit oil and is way off on the PSI.

Is it the gearcase or the engines crankcase with the issue??

He said checked Head, water jacket, and what ever else there is. I posted what he told me.
I also know I'm getting rid of this Honda and going back to OMC!

Where are you? I buy Honda "orphans".
It's probably not a head problem. I don't know the 50 but some Honda outboards get water in the oil from a seal where the water has to travel through the oil case to get to the block. Another place water might enter is at the oil fill adapter mounted on the side of the block. Not sure yours is configured that way but it's something you could look for.

The parts are very cheap in both cases but the power head has to be removed to effect a repair.

Good luck.

jgmo, you had the ONLY legit answer! That's what my mechanic told me. He said it was most likely a gasket/O-ring
at the bottom of the head, and as long as I didn't use "muffs", everything should be fine.
They're a Mercury dealer in a town of less than 200 residents.
Thanks again jgmo
TM2

There is a rubber boot seal on the shift linkage right next to the water pump, if that is dry rotted you could also get water into the lower gear case there. Cheap and easy fix.