1974 Johnson 15 broken bolts removing the lower unit

Bullie

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Dec 20, 2014
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As I removed the lower unit I broke off one side of the bolts. What is my best course of action?


Another issue. I never expected dirt daubers to be this deep in the motor. They have the topside hole blocked too.


Best way to clear them out? No problem with the ones in the picture. I have already removed those. More concerned with the dirt in the top half.
 

F_R

Supreme Mariner
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Jul 7, 2006
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28,226
The ones that are sticking out, grab with Vise Grips and unscrew them....with lots of heat on the aluminum along the length of the bolt. Use hot heat, like acetylene torch hot heat. Propane isn't hot enough. The ones that aren't sticking out, well you are about to learn how to drill out stainless steel bolts and insert Heli Coils. That is a learned skill. You may be better off taking it to somebody that has already learned. DO NOT use Easy Outs, there is no such thing. It isn't Easy and they won't take it out. Once you break it (or a tap) off in the screw, the game is over.
 

TexMonty

Seaman
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Dec 26, 2014
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And be very carful heating the aluminum. It won't start to glow like steel, if you overheat it you will see how fast aluminum turns to a puddle. If you are not accustomed to working aluminum/stainless I agree a pro may be worth paying to do it for you.
 

Bullie

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Wish I had read this BEFORE buying the easy out kit. It looked so simple on the videos. LOL I was able to remove the center bolt but all I did did with the easy outs was make a smooth hole in the lower hole and broke a drill bit off in the upper hole. How screwed am I?
 

V153

Lieutenant Commander
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Apr 16, 2011
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Realize it's a lil late to chime in now but have you ever heard of penetrating oil? Not to be a smart azz but a lil patience and some PB Blaster can go a long way.

Combine that with some heat (aka "blue wrench") and I'll bet the body count might've been a lil lower?

Regardless. Now that you've broken off a drill bit you're at least a lil bit 'screwed'.
 

Bullie

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Yep. I did a whole chain of dumb things. I think I am a DA too. I should have slowed down and given you guys a chance to answer.
 

Bosunsmate

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Apr 7, 2012
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If you have only done it to one bolt, dont stress that much. My motor is missing one of those bolts due to damaged threads and its never caused me an issue
 

Bullie

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Well, at this point it is actually two of them on that side. The one in the middle I was able to extract with the information I had at the time. I don't know exactly how screwed I am concerning the other two. Let me explain the situation a bit better.

Referring to the picture above, the top bolt is the one I broke the bit in...possibly 1/4" of bit broke off, the bolt is still slightly above flush. The bottom bolt I drilled through and then tried the easy out. It was just a smooth hole when I gave up except for some of the old bolt I had pried out of the threads with a center punch. I don't think (at this point) that I destroyed the hole/threads on this one. I was able to get to remove some, just one thread, of the old bolt from the threads at the top of the hole. I didn't think I was super screwed on the lower hole as the threads were still intact but stopped until I could ask how to proceed. When I broke the bit in the top hole I figured my lack of experience and patience was about to cost me lots of time and maybe some money...
 

fireman57

Captain
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Aug 24, 2004
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3,811
If you have a machine shop close they can get them out pronto for you and make sure the threads are good at the same time for not much money usually. It's great peace of mind when you get it back from them. Call a couple shops and see what they will charge.
 

Bullie

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Dec 20, 2014
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#1 Bolt This is the one with the bit broken off in the top. Approximately 1/4 inch of bit maybe.


#2 Bolt Drilled completely through. I am not certain but I don't think, at this point, that I screwed so off center that I got the threads in the casting. Some of what you see there at the top are threads from the bolt that I pried loose from the side.
 

Bullie

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Dec 20, 2014
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Fireman57, I may end up doing exactly that. I definitely did not do a very good job in my rookie attempt at broken bolt removal.
 

fireman57

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Aug 24, 2004
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Like it was said before, ez outs are junk. Cause more problems because they are harder and more brittle than the bolt. They break easily and you can't really drill them.
 

orbanp

Petty Officer 1st Class
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Jun 26, 2011
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324
Find a machine shop that has an EDM (electro discharge machine) to remove broken in bolts.
The EDM "burns out" the broken in bolt as well as easy out.
After that use helicoil.

Good luck, Peter
 

Greg O.

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Jan 9, 2011
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125
If a bolt is protruding even just a little above the surface, I ha ha pretty good success taking a nut that will just slip over the broken bolt and welt inside the nut to the bolt. This heats the bolt and gives a place to use a wrench. Let it cool some before turning. While it is still pretty warm spray with a penetraiting oil. Then very slowly work the wrench back and forth. It might take several tries to get it loose. I have used 6 nuts sometimes before it came out.
 

jb93

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Feb 21, 2008
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267
As several stated, find a local machine shop. Probably $50-60 to fix your mistakes and you will be back in business. Good machine shop will probably have soda blaster or some type of appropriate equipment to strip the lower unit for you. Could save you some time from hand stripping or another trip to a blaster later on down the line. If not feasible, look on ebay or other sources (AOMCI) to see if you can find a used housing.
 
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