Help removing a broken bolt lower unit bolt

[marty53]

Hey guys, just got a 1983 E50BELCTA 50hp evinrude with an old starcraft I picked up. It definitely needs some work, I'm not even sure I'm gonna keep it but one major issues is the lower unit is off, and there is a broken bolt in the midsection (one of the lower unit attachment bolts). There is about 3/4" of bolt there, and the threads look decent. I was going to try a method I was reading about, threading a nut on, then soldering it on. this is made complicated by the fact that I'll somehow need to invert the powerhead to do this. Couple questions for the experts:

-will regular plumbing silver solder and torch work for this?
-does anyone know what size nut goes on these bolts?
-are these generally considered good engines (worth putting some time into)?

I figure I'm at least looking: replacing fuel lines, rebuilding carbs, water pump kit. Some wire splicing from mouse damage. I tested compression with a weak battery got about 90psi on both cylinders. Seems a little low but I had a really weak battery was barely turning the engine over. Flywheel turns easily by had and nothing is seized up.

Thanks for any help,

Marty

 

[jakedaawg]

Either use vice grips and see if you can work it back and forth at all.

To put a nut on it I weld them. I do not belive silver solder will be strong enough

 

[marty53]

jake-

My concern with popping vicegrips on is that I'll crush the threads and ruin the possibility of threading a nut on. I agree about silver solder, has mentioned here in this vid: https://www.youtube.com/watch?v=CDgtfCuB0ok

 

[jakedaawg]

This is one of the four main cap screws that hold the lower onto the mid? If so, who cares about the threads, you will need to replace the bolt anyway. Usually, if the head broke off the shank comes out fairly easy.

I cant watch video. I may be thinking of another bolt than what you mention though so take this with a grain of salt from 1090 miles away.

 

[jakedaawg]

Do you have enough thread to get two nuts on? Use one as jam nut and bottom one to turn out bolt?

 

[jakedaawg]

They also make a tool called a "stud remover" if you have enough length you can get one on it will work best. Use a quality tool. Not a HF Chinese thing.

 

[AndyD]

If you have access to a welder I agree with the above, Weld a nut to the bolt end, Try soaking the seized bolt in a mixture of ATF and Acetone. Best penetrating liquid you can't buy (at least not pre-mixed). Use a beam type toque wrench if you have one and try not to exceed breaking strain for the bolt (you should be able to look up an approximate value. If this fails use an impact gun on low torque setting and let it hammer in and out repetitively while re-applying penetrating mixture. What you are trying to do here is create tiny fissures in the corrosion to allow the ATF Acetone wixture to penetrate. Patience is a virtue in a case like This. I managed to get all 8 plugs out of my F150 Triton with the long nose plugs without breaking them. Cost some people hundreds of dolars to change plugs on this engine when the broke while removing. it took me almost a day to get them out, a combination of soaking and Tiny tuens (like 1/16th of a turn at a time) Moral of the story GO SLOW and son't apply too much torque and you will succeeed.

 

[marty53]

great info guys thanks! jake- there is not quite enough thread to get two nuts on, I did think of going this route. I like the stud remover idea, seems perhaps the easiest way out of this. First I may try some heat and vice grips.

Failing that, go see someone who can weld. Thanks

 

[racerone]

Heat the area where the bolt threads in.--------Aluminum expands at twice the rate of steel and it will release well before any danger of melting the aluminum.

 

[ohio stan]

When the bolt breaks the rest of the way off--weld a flat washer through the hole,-then weld a nut on to the washer'. Then weld the center of the nut agagin.It takes 3 times of serious heat to get the bolt to come loose, This works 98% of the time. If it shears off do it again. Stan

 

[valvebounce]

The problem with a steel bolt in aluminium is when it corrodes it forms aluminium oxide in the threads.Usually a stuck bolt needs heat before it will budge.
There are no lubricants on the market that will soften the aluminium oxide.White vinegar kills aluminium oxide,but it's a long,keep going back to it process.
I have heated the aluminium casing on occasions,and wet the protruding thread with cold water,which sometimes helps to shrink the steel by taking the heat out of the steel thread and not the aluminium.
The other way round it is,drill the bolt out and retap for a slightly larger bolt.

 

[rebuilt]

I've got an '89 60hp that did the same thing to me on a water pump job. The smooth bore of the bolt froze in the long through hole it passes through, corrosion.My cap bolts are stainless. I'd bet yours are too. Heat, soaking in power blaster, gentle rocking back and forth, repeat. The point that the bolt is sheared off and of no use to you is well taken. It needs to be replaced anyway, so no real harm if it get chewed up. I have used a small, quality pipe wrench to coax sheared, corroded bolts out.HF chinese won't grab with the bite you need. My engine is salt water only, I'm kinda used to it.Bolt Depot is the ticket for replacing stainless or grade 8 engine bolts, once you find the size and thread count. Box stores in my area suck. I only buy the higher grade of stainless bolts from them, stainless 316.

https://www.boltdepot.com/Hex_bolts_Stainless_steel_316.aspx.

Good luck getting it going again. It sounds promising.

 

[Parrothead71]

Have someone weld a nut on it. Lay it on top and completely fill the nut with weld. That will heat everything up plenty hot to turn it out, plus when using a nut you can use a wrench to turn it. I've gotten broken bolts out of aluminum heads this way.

 

[marty53]

No Title

Hey guys thanks for all the great tips. I ended up trying a bunch of stuff, but ultimately what worked was lot of heat cycles, (at least 5) and threading two slim nuts on using one as a jam nut as jakedawg suggested. I didn't think I had enough thread to do this until I found some slim nuts. It took quite a bit of coaxing. Head with my torch, spray some PB blaster, wait, try the nuts, repeat. I had to real crank the nuts together or else they'd just both spin. Then very carefully and slowly crank out using the bottom nut. I'm glad this worked because I would have had to bring it somewhere to weld a nut on. Thanks again