Water intrusion 1972 Johnson 25HP

[CatfishMN]

Hi everyone,

When I changed out my lower unit oil last fall, I noticed some water intrusion in it, very milky even after not running for about a month. When I changed it the previous time, I put new seals on the filling screws, so I don't think that is the culprit.

So I wanted to do the impeller this spring, and I figured while I had it apart, I would try to address the intrusion issue. Looking at the diagrams, it shows a big seal when the gearcase is split apart. Could that be what has failed? If so, it shows as unavailable. Is there any other place that could be the cause of the intrusion?

Thanks in advance for any help!

 

[AlTn]

Re: Water intrusion 1972 Johnson 25HP

iboats..marine parts...johnson...internal engine parts...lower unit seal kits..1972 25 hp...sierra or mallory...either will have that spaghetti seal you're referring to in addition to the other seals needed..using the search feature..type in lower unit seals and you can find a lot of info on doing this job, you tube has some diy videos on this..not necessarily specific to your motor, but close enough

 

[CatfishMN]

Re: Water intrusion 1972 Johnson 25HP

Thanks! Is there any way to test if that is for sure where it would be coming from? Are there any other usual suspects? I suppose if I ordered the seal kit and replaced all of them, that would be a good start..

 

[AlTn]

Re: Water intrusion 1972 Johnson 25HP

using the search function here..type in....lower unit pressure test..plenty of reading

 

[boobie]

Re: Water intrusion 1972 Johnson 25HP

The best thing to do is have a pressure & vacuum test done on it before you take it appart. That way you will know exactly where the prob is.