Bolt holes blown on exhaust housing

[Jamesnev]

Hi, this is my first post here. Please excuse any lack of terminology or basic experience, as this is my first outboard and I have no mechanical training.

I recently bought a '79 johnson seahorse 15hp, and have since been fixing the mistakes of it's past owners - and there were many.

The one I'm stuck on right now is that after I replaced the seals and water pump, I go to bolt the lower unit back on, and all but 2 bolts go right in, those 2 just spin and spin.

When I took the lower unit off I noticed that only 3 bolts were the originals, the others were various different lengths, and one had a tiny wire loosely spun around it.

I replaced the bolts, and now I see why he had different screws in there, one of the bolt holes is completely destroyed about 2/3 of the way up, you can see the threads exposed up the side, the other is stripped about 2/3 or more up inside the hole. I ended up using 2 longer bolts, and I feel them connecting with the threads, though I can tell they aren't as tight as the original bolts.


I ran the motor for the first time this weekend and it did great, the only thing I noticed is that when I got the boat back out of the water, there was water spewing out the side of where the lower unit connects, and it was only happening from the side those bolts are on. Another thing to note about this is that the little drain hole on the lower unit seemed to be clogged, perhaps making water build up and spew out the side?

So I guess my question is, do I need to worry about this? The longer bolts didn't loosen any from a day on the lake, but I don't know what misplaced water pressure will do in the long run.

I'll include a picture when I get the chance to give y'all a better idea. Thanks!

 

[hardwater fisherman]

There is something called helicoil inserts thread repair. I have never used one but I know someone who has and they seem to work.

 

[boobie]

The helicoil inserts work really good. I've used them for years.

 

[Jamesnev]

Would the bolt hole that's blown out be able to hold something like that? Like one of the holes is intact just stripped, the other has a chip missing out of it, almost half an inch wide from where the threads start and it goes up about an inch or so into the housing. May be hard to visualize, I haven't been home to post a picture of it, I will tonight though.

Thanks for the quick responses!

 

[boobie]

You can get the helicoils in different lengths. Figure out what you need.

 

[Jamesnev]

Sounds like the heli coils are the way to go then! I'll see what I can do with it next week.

Here's a close up shot anyway so you can see. I'll find out what size coils I need and let you guys know how it goes! Thanks again

 

[F_R]

A heli-coil won't help in that one that has the side missing. It looks like he tried to fix that with epoxy. You will have to rely on the remaining ones to hood the gearcase on. FWIW, I have used many thousands of heli-coils, both in repair business and manufacturing. Great product. The ones we used in manufacturing were actually there to strengthen the hole.

 

[Jamesnev]

That's what I was afraid of, I guess I'll coil the one that's still intact and hope for the best with the other!

None of you think it's a big problem that water builds up in the unit and spews out the side? Guess it just goes with those not-so-tight bolts?

 

[F_R]

Any water that leaks out there was destined to go out through the underwater exhaust outlet through the prop hub anyway. No big whoop.