Can I JB Weld this?

[Raymond33]

I have a Yamaha 50 hp 2-stoke that have issues with water on spark plugs.
I lifted the motor and saw that both the engine block and exhaust plate is damaged.

How can I repair this? Can I use JB weld or is there a better product to use?

I also have concerns about the area on the exhaust plate where the water is flowing, it was completly clogged with hard packed sand.

I cleaned it as best as I could but this piece did not look in good shape, Will there be any problems if i leave it like that or does it need replacement? I tried unscrewing it but it was really stuck.


I don't want to remove the exhaust plate if I don't need to because im scared that there will be more broken bolts if I try that. 3 broken bolts is enough.

Thank you

I'm glad that this forum exists

best regards from Sweden

Ray

[ausnoelm]

JB weld is a patch, not a repair, your choice, patch it up and do it properly in 6 months time, or do it properly now.

[Raymond33]

JB weld is a patch, not a repair, your choice, patch it up and do it properly in 6 months time, or do it properly now.

What's the proper way of doing it?

Screenshot_20240315_014557_Gallery.jpg

[ausnoelm]

Weld if possible then machine flat or replace with new parts.

[99yam40]

if you can clean it well enough to get the JB to stick, it will hold up for a period of time, but not sure how long.
I had a corrosion hole near the stat on my C40 welded up on my block years ago, it was a pain to get it covered/sealed properly and it was not on a machined surface

[Raymond33]

Thanks for the answers, anyone know what the damaged screw is for?

This engine is from 1982 so I'm only hoping to get 1-2 more years out of it and the summer in Sweden is very short so I think my best option will be to go for a cheap patch with one of these:

Screenshot_20240315_195012_Chrome.jpg
Screenshot_20240315_195051_Chrome.jpg

[panasonic]

If you are going to do that then make sure you get the surfaces really clean. Scrub with a stainless steel brush and acetone, Mek, brake clean or other good solvent. The oxidation needs to be removed from the surfaces so the epoxy can stick well.

Get something flat like a a thick piece of glass or a piece of scrap granite countertop and apply sticky sandpaper to it to flatten the whole area.

You got nothing to lose at this point. The screw in question is holding a sacrificial anode from the looks of it.

Good luck

[Raymond33]

If you are going to do that then make sure you get the surfaces really clean. Scrub with a stainless steel brush and acetone, Mek, brake clean or other good solvent. The oxidation needs to be removed from the surfaces so the epoxy can stick well.

Get something flat like a a thick piece of glass or a piece of scrap granite countertop and apply sticky sandpaper to it to flatten the whole area.

You got nothing to lose at this point. The screw in question is holding a sacrificial anode from the looks of it.

Good luck

That's very helpful thank you.
Sorry I don't know that a sacrificial anode is. Do I need to replace it?

I also wonder how much I need the torque the bolts when I put it back together?

[Raymond33]

I also wonder about this port that seems to not lead anywhere that was filled with some kind of sand, same kind of sand that was all around the sacrificial anode. Its like they filled this space so that it would not be empty. Anyone know about this?

Screenshot_20240313_021705_Gallery.jpg

[amahaork]

it is not sand, it is oxide result of electrochemical reaction between: stainless steel screw, zinc sacrificial anode and aluminum body of motor. manual should clearly state when sacrificial anode has to be replaced as regular maintenance.