1973 evinrude 85 lower unit mystery plug

[greasemonkeyjmj]

hello my dad has a 1973 evinrude 85 horse. 2 weeks ago the lower unit locked up on it, well he had another unit that needed a seal kit, because it got to where it was getting water in the oil when in use. we installed the seals, and bolted it up to the motor, but when we started adding oil to it the oil started seeping out of a hole near on the starboard side near the water pump intake. well i looked at the other lower, and it had a allen type plug in it that was 1/4 of a inch or so long. so i screwed it in the replacement unit and it screwed all the way in and didnt bottom out. what is this plug for ? and what keep water from seeping in around the threads, as i didnt see any type of seal . and is it supposed to bottom out ?

thanks

 

[ezeke]

Re: 1973 evinrude 85 lower unit mystery plug

The lower bearing set screw holds the lower driveshaft bearing.

 

[Vic.S]

Re: 1973 evinrude 85 lower unit mystery plug

The parts list does not show any seal but if its not sealed it will allow water in!

I'd put it in with some jointing compound to be sure it's water tight.

 

[greasemonkeyjmj]

Re: 1973 evinrude 85 lower unit mystery plug

any idea on how far to screw it in ? it seemed like when i kept screwing it, that it went all of the way inside the case, and would have fell who knows where if i had not of srewed it back out some