1973 Evinrude 25hp lower unit failed pressure test.

[clemsonfor]

Ok so I rebuilt this lower with the parts that were bad. All new seals etc. Ran it, next day or two noticed gear oil leaking. So pull it off and pressure test it. Leaking under water pump housing. So I pull it off and pull the plate up to see. Well the drive shaft seal is not leaking but it's coming from the front of the motor that void in front of the drive shaft that has the little drain hole in it...see pic. My only thought is that there is a crack in there? I'm trying to clean the crud up in there to see if I can see anything. Any thoughts on the source?

Where I am pointing with the screw driver is where the bubbles come from down toward the bottom best I can tell.

 

[F_R]

So, if you actually witnessed bubbles when pressurized, I would suppose it is cracked or has a bubble in the casting. Both would be rare in my book.

Um, maybe it is a freeze crack? That would be rare here in Florida, I guess.

 

[clemsonfor]

Duplicate post....

 

[clemsonfor]

Ok I cleaned it up, sprayed carb cleaner in there plugged the hole up and used a screwdriver to rub all the sides. Then air to clean it and sprayed it and more air. Then I put pressure to it and used a soapy spray. It's best I can tell it's bubbling on the bottom of that void closes to the drive shaft tower. I don't see any cracks.. pitting maybe or small crack has to be what's leaking.

My plan is to clean it best I can and let JB weld run down into there and cover that area. Probably fill up above the existing durian and then drill another drain hole higher up.

 

[clemsonfor]

So, if you actually witnessed bubbles when pressurized, I would suppose it is cracked or has a bubble in the casting. Both would be rare in my book.

Um, maybe it is a freeze crack? That would be rare here in Florida, I guess.

I'm in SC. It does get cold enough to freeze. That drain when I got it was leaking cruddy water so it was open...but if the milkshake on the inside froze? I have pretty good eyes even at 40 and I had a light and my face down there on the top of the hole looking and I can't see anything that stands out. I'm almost thinking porosity in the metal, but that wouldn't make sense. Did they test them at the factory? This Kotor has been in my wife's family since new but no one alive knows enough history on it to ask if the lower always had some water in it?

 

[clemsonfor]

I have been trying to clean the area best I can with brake clean, and a gun barrel brush on a rod chucked in my drill brushing out the bottom of the cavity, spraying it out. Cut a small piece of scotch bright green pad and put down there and run it around with a screw driver. It looks like a pin hole to me, nothing that looks like a crack.

 

[clemsonfor]

I took a picture beat I can get it too show up. Look in the lower right side of that triangle. I thought I saw one dark circle/hope but this looks like two when I zoom the picture in. Hopefully the quality will upload here.

 

[racerone]

It should not be hard to find a good gearcase.-------visit the ----aomci-----website and place a free wanted ad.-----Local swap meets have these parts motors available for around $100 I hear.

 

[clemsonfor]

It should not be hard to find a good gearcase.-------visit the ----aomci-----website and place a free wanted ad.-----Local swap meets have these parts motors available for around $100 I hear.

I'm going to put JB over it. I am sure that will seal the hole. But your right I could probably get a whole engine let alone a bad lower unit and scavange the case. But I have everything built and done in this one and it saves the cost and the labor to swap it all out.

 

[clemsonfor]

To update this with the results. I let the JB Weld cure for about 30+ hours. I put pressure to it and there were no bubbles from that void in the lower unit where it was leaking before. Hopefully this will be the end to that leak .

 

[Crosbyman]

give it a good carb cleaner wash out again and dump an ounce of fiberglass resin over it . that should be the end of bubbles for good drill a new drain above it