I would plug that hole. If it lets air out it will let water in. Best way to tell is put the top plug in when full and continue to pump oil in an see if it comes out the bleed hole.
When you changed the oil did you put new gaskets on the drain and vent plugs? Hopefully that is all the problem is. If not, you have a bad seal(s) somewhere.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va
fishn_a_ledge, dfar LIKED above post
I would plug that hole. If it lets air out it will let water in. Best way to tell is put the top plug in when full and continue to pump oil in an see if it comes out the bleed hole.
MEMBER CRAPPIE MAFIA
That weep hole in the picture is a water drain for the cavity below the shift shaft housing. If you close it up you will run the risk of cracking the lower unit when in freezing weather.
I would say you have a bad seal. My guess would be the the drive shaft seal or shift shaft seal.
I have spent most my life fishing........the rest I wasted.
PROUD MEMBER OF TEAM GEEZER
PICO Lures Field Rep
Just a thought, but make sure you didn't leave the washer off of the screw. Did this once and it leaked lower unit oil.
You can't finish what you don't start