'83 50hp what's the secret

[fireman57]

I have an '83 50horse evinrude that I got about two years ago. Twice last summer and once already this summer I have had to drop the lower unit and replace the gasket that the exhaust tube and lower unit hold on. For some reason the exhaust tube will loosen and drop down and then it blows this gasket. I have tightened the bolts on it as much as I dare. I don't know that locktite will work because even the white is only good to 400 degrees and I know it gets hotter than that there.

 

[Joe Reeves]

Re: '83 50hp what's the secret

You say.... "I have had to drop the lower unit and replace the gasket that the exhaust tube and lower unit hold on. For some reason the exhaust tube will loosen and drop down and then it blows this gasket."

Try as I might, I cannot visualize what you speak of even after studying the exploded parts view. Could you explain somewhat more in detail? It sounds like you have something missing.

 

[fireman57]

Re: '83 50hp what's the secret

Thanks Joe, and good to hear from you again. On my engine when I remove the lower unit there is an exhaust tube that bolts on the base of the powerhead and runs down to the through hub exhaust. It is held on by six bolts. There is a gasket that goes on under it and the water tube flange (2 bolts) then the mid section of the lower unit bolts up to that. For some reason the exhaust tube bolts will work loose even with the lockwashers on and drop down. At this point the mid section gets super hot as you can imagine and the tube rattles around in there until I get back to the trailer and home to redo it all. The gasket will blow on the port side and I get water running down the hot mid section at this point.

 

[Joe Reeves]

Re: '83 50hp what's the secret

I'm familiar with the long inner exhaust tube but I have never heard of one coming loose, nor can I imagine why one would.

I assume that you're removing the powerhead and adapter plate in order to replace the gasket etc as I know of no other method of doing that job otherwise.

With out actually being there, I don't have the cure for that problem EXCEPTING that possibly you do not have the proper components installed at the bottom of that tube that would be compressing it, holding it tight to the lower unit assembly. I say this as with everything installed, it seems to me that it would be impossible for that tube to drop even with all the bolts removed.

 

[fireman57]

Re: '83 50hp what's the secret

I actually found it easier removing the mid section than the powerhead to replace. I glue the gasket on the adapter, then bolt up the exhaust tube and the 2 bolts for the water tube then reassemble. My rubber gasket looks good at the bottom that the exhaust tube fits in but I will reinspect it the next time I have it apart. What else is there that keeps it from dropping down? Number 63 keeps blowing out the port side. After that I get a steady stream of water down the midsection. When I take it apart that is when I find the exhaust tube loose.