1978/1981 Evinrude 115hp Lower Unit Small Hole in Front?

[atktom]

Can anyone please tell me what this small hole is at the front of my lower unit. I scrapped away old crust but the hole seem to be plugged as I get a vacuum when I try to see if any thing comes thru it.

 

[racerone]

Are you 100% sure that is a 78 / 81 lower unit , yes or no ?-----Later lower units used a hole on the leading edge for a speedometer pick up.----Post pictures of the leading edge below the cavitation plate.

 

[atktom]

I am not 100% sure. I think it came off of 1978 Johnson, the guy I bought it from spray painted it silver. It has been working fine on my 1981 Evinrude for a couple of years. I only pulled it because of the leak you see. I have not put any oil back in it yet. I installed new upper seals & shift rod O ring and did a pressure/vacuum test and it did fine on that. Put new water pump on. Getting ready to reinstall. Also noticed another little hole down in front where you had me take pictures. I put a wire in it and it seems solid inside too. Thanks in advance for your help Racerone.

 

[racerone]

First picture shows hole for speedometer water pressure signal.

 

[atktom]

Should I leave them alone or seal them up with JB Weld, etc. I do not use a speedometer.