1962 Johnny 75hp Electramatic revisited. Lower unit question.

[vitallus]

Hello again guys. The old Johnny is still running great-and charging (hooray). Got a new concern now though. I replaced all the seals and gaskets and o-rings I could get to (without actually disassembling the lower unit to do so), because I was losing gear oil and getting water in it. Driveshaft seal, prop shaft seal and all those o-rings, new gaskets for the impeller housing and upper driveshaft bearing housing, and new fill/vent plug gaskets. Been running it for a couple months now and I'm still losing it and getting water in it. I have noticed after running it for longer periods of time, that when the boat is out of the water, a black-ish oily substance seeps out slowly from two (what appear to be) weepholes in the lower unit. One of them is just above the stamped "freeze plug" up top by the lower unit vent plug, and the other is just in front of the exhaust port on the bottom of the cav plate. I can take some pictures and post them if it'll help, but I'm wondering if Joe Reeves or F_R or willyclay know what these are and if they're actually supposed to be there or if they're supposed to be plugged with something... And are these things a possible culprit for my fluid issue? Or is there another seal or o-ring or something under somewhere that could also cause the oil to mix with water? I'm all ears.

 

[vitallus]

Re: 1962 Johnny 75hp Electramatic revisited. Lower unit question.

Ok... no takers? Well, from looking at my parts motor, I've determined that the weep hole in front of the exhaust outlet is supposed to be there, so I'm assuming that the one by the vent plug is also supposed to be there. And from what I gather, the blackish oily scum that's coming out of these weep holes is excess spent two stroke oil that did not get burnt and it collects in a little pool area and drains out the weep holes. So this is normal? Next question. Is it possible to pressure test a lower unit to find out where its leaking? I can probably figure out the "how," but if so, what value should I pressurize it to in order to find my leak?

 

[Willyclay]

Re: 1962 Johnny 75hp Electramatic revisited. Lower unit question.

And from what I gather, the blackish oily scum that's coming out of these weep holes is excess spent two stroke oil that did not get burnt and it collects in a little pool area and drains out the weep holes.

I missed your first post but, yes, it sounds normal to me. The motors from that era were very "dirty". Since I have never pressure tested a gearcase, I will defer to the experts and continue to learn when they post. Good luck!