1960 Evinrude 40hp Lark, LU Overhaul

I found three hairline cracks in the lower unit case at the water pump. Should I bother trying to repair? Could I JB Weld the cracks to seal the exhaust gases out. How hot does it get down there?

Also, behind the shift rod hole there's what appears to be a drain hole but it's blocked. Does it connect with the hole on the starboard side above the prop?

The clutch dog has a groove on one side and not the other. I didn't notice which way it was installed. It is reversible but I don't know and my manual doesn't indicate the orientation. Any ideas?

Sorry, I got a new camera and for some reason the photos are not a valid format. I'll have to figure that out so that I can post photos.

Re: 1961 Evinrude 40hp Lark, LU Overhaul

Re: 1961 Evinrude 40hp Lark, LU Overhaul

The P or a groove cut is on the prop side of the dog.

JB Weld may hold minor damage. TIG welding it with Argon is probably best.

Re: 1961 Evinrude 40hp Lark, LU Overhaul

Re: 1961 Evinrude 40hp Lark, LU Overhaul

I've added photos of the case cracks and the mystery drain hole

Re: 1960 Evinrude 40hp Lark, LU Overhaul

I cant see why that drainage hole's orifice would not connect with the others. It is simply to drain the gearcase of spent cooling water.

Those cracks seem minor from the picture, and Im sure JB Weld would be satisfactory, welding may cause you more issues anyways.

Hopefully others will jump in with some ideas.

Re: 1960 Evinrude 40hp Lark, LU Overhaul

Where those cracks are located, I would carefully tap the parts back into the most upright position possible. The water pump plate set's here, and requires a tight seal, or you will have pick-up problems with the pump. When tapped back into place, clean around the cracks down to bare metal, and use Devcon, or JB Weld. I would not try welding because you must maintain that flat surface for the pump plate. The other is a drain hole for the gearcase casting. Clean it out if you can, but I would'nt worry about it.

Re: 1960 Evinrude 40hp Lark, LU Overhaul

R.Johnson said:

I would carefully tap the parts back into the most upright position possible.

Click to expand...

The casing isn't bent, just cracked. I read about the possible cracks in my Seloc manual but they were quite visible since the crud looked like it was scraped off along the cracks on the exhaust side. I don't know why it would be so clean just along the cracks. Maybe the leaking one way or the other kept these areas from having any build-up.
Living in Canada I would really like to get the drains working. I poured varsol into the cavity in the exhaust housing yesterday and let it sit and it's still there today. Water will never drain out of there if that's the case. I may have to work a fine wire in there or pour some calcium and lime remover (CLR) down there to soak.

Re: 1960 Evinrude 40hp Lark, LU Overhaul

I did not mean that the case was bent. I meant the walls of the cavity are seme time's bent out from the crack.

Re: 1960 Evinrude 40hp Lark, LU Overhaul

See the post here of the Craigslist vulture giveaway...its in the dumpster, but ya gotta pull an address...(some people never learn..)..good parts...

Re: 1960 Evinrude 40hp Lark, LU Overhaul

R.Johnson said:

I did not mean that the case was bent. I meant the walls of the cavity are seme time's bent out from the crack.

Click to expand...

The cavity walls are straight, I think I just need to JB Weld the cracks.

I finally got the drain hole cleaned out. Logic told me the cavity is drilled down to the drain hole drilled in the starboard side so I taped a drill bit to a chain saw file and hand drilled through the years of build-up. It was like a rock but it's open now. Probably a good idea to blow compressed air into the hole every now and again to blow out any sand or carbon.

Now to sand, clean and paint it.