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Is this normal??

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Igotjesus88

New member
Hey,

first I couldn’t find a new member thread but my name is Casey.

I have a question about the water pump area of the lower end unit on a 1975 15hp evinrude. It’s 15504C. Is their supposed to be a little cut out on the other side along with a bigger one that water goes through?
 
Welcome, Casey. Yikes....what does the rest of the motor look like? Gotta be a saltwater motor, eh?
 
Well, ..............If that's the only bad spot, you can clean it up good and try to shape a piece of aluminum, then bond in place with JB quick weld. You can add some sealant to the plate when you install back onto your finished surface. Might like to anti-seize all bolts and be sure....if you get motor running, to flush with fresh water after each seawater use. Might be
livin' on "borrowed time", with this one.
How is the lower unit oil....? Free of water?
 
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timguy said:
Well, ..............If that's the only bad spot, you can clean it up good and try to shape a piece of aluminum, then bond in place with JB quick weld. You can add some sealant to the plate when you install back onto your finished surface. Might like to anti-seize all bolts and be sure....if you get motor running, to flush with fresh water after each seawater use. Might be
livin' on "borrowed time", with this one.
How is the lower unit oil....? Free of water?
Click to expand...

Ok sounds good. Thanks! I will try that. Also just a side note. Does water usual get in to the area of the shifter when out in the water? Also this motor will not go in salt water again.
 
Yes it's water in shift shaft chamber when in use. Of course, no water is allowed in the transmission/gearcase itself......only the proper marine gearlube. This housing is cast aluminum, bolts are stainless steel.
 
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Note: This broken out opening must be able to hold suction because once your boat is on step, it will be barely at or even...just above the water level.
 
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timguy said:
Note: This broken out opening must be able to hold suction because once your boat is on step, it will be barely at or even...just above the water level.
Click to expand...

Your extremely helpful. Good news the gear oil looked great! Ok so if water get in the shift rod area how does it get out once out of the water? Or does it just sit in there? I was just gonna do some flex sealant but since you said it needs to hold a suction I’m going to do the aluminum plate route. Also this is crazy to think about but I wonder how long this thing has ran without water. The water pump didn’t look bad at all btw. Good thing bought the boat cheap.

how thick of aluminum should I go?
 
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Alum. maybe 3/16". Might not have ever been used with that piece eaten away, or if it was used, maybe never up on step. Might have sat around and got eaten up, then YOU became the new proud owner. There should be a little drain hole at the base of that shift rod area....might wanna make sure it's open and clean oxidation, etc. out of the area. You can use hydrochloric acid......that's available at about 30 percent solution.....or you can physically scrape stuff out. You probably know to handle it with care. When done you can neutralize with baking soda and water. I clean rusty fuel tanks with it.......often soaking overnight. Vinegar is a mild hydrochloric acid, of course.....but takes too long.
 
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timguy said:
Alum. maybe 3/16". Might not have ever been used with that piece eaten away, or if it was used, maybe never up on step. Might have sat around and got eaten up, then YOU became the new proud owner. There should be a little drain hole at the base of that shift rod area....might wanna make sure it's open and clean oxidation, etc. out of the area. You can use hydrochloric acid......that's available at about 30 percent solution.....or you can physically scrape stuff out. You probably know to handle it with care. When done you can neutralize with baking soda and water. I clean rusty fuel tanks with it.......often soaking overnight. Vinegar is a mild hydrochloric acid, of course.....but takes too long.
Click to expand...

Ok sounds good. Will the hydrochloric acid hurt the seals at all when sitting in there?
 
A replacement gearcase is your best option.----Just salvage all the parts and install in a fresh water case.-----E-bay would have lots of them.
 
Racer has a good point. Perhaps you could also check Tim's Outboard in Hackensack MN. Talk with Mike, Dan, or Teresa. 218 682 2331. If you decide to repair what you have, the hydrochloric acid should not harm the rubber for a short-term cleaning.
 
Those gearcases come with a drain hole.----likely plugged------Note I suggested replacing that mess.----Gearcase from 74 to 92 is the same.-----93 to 2007 will also fit.
 
I don’t have the money right now so I’m making do. I don’t go far at the lake where I fish. Also I have a 45 pound thrust trolling motor.
 


looks like that side goes a lot lower than the shifter. I need to clean it out more. Also he recommended to drill the drain hole a little bigger.
 
Here is a screenshot from our parts guide here. Gotta dig until the drain hole is open. Plug the shift shaft opening.....if you haven't already. Soak with acid.....I know the money crunch....it's always good to try and do it right the first time, but.....maybe you can make this work. Objective is to keep motor running with good water circulation and keep gear oil clean and free of water. As previously mentioned.....ALWAYS use anti seize. These are stainless bolts but the aluminum will oxidize and grip to them. The factory often uses a mild Loctite on them but I have yet to ever have one work loose. Even when working and rebuilding chainsaws I use anti-seize on case bolts, cap screws.....etc...where originally there was Loctite.
 

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