78 85h Evinrude broke cylinder head bolt, mechanic says big problem

[MadtownChris]

Hey all... I stupidly over tightened one of the cylinder head bolts in my 1978 85hp Evinrude - at least that's what I assume it is - one of the bolts that holds the whole water jacket and top of the cylinders on and I broke it off way down in there.

I took it to a local shop and it can't be removed and replaced without taking off the whole head.

They told me that they can't do it since they'd need a special alignment rig / jig or something like that. They directed me to a place that's about 8 hours away! And I'm really in boating central here in Wisconsin where I think the motor was built.

Do you have any advice? Should I call around to find a shop that would do it or would I end up with a bad repair without the specialized rig? I'd attempt it myself but it's a little advanced for my skills.

Thanks

Chris

 

[Tim Frank]

I'd suspect that they were referring you to a machine shop where they can do that kind of a job accurately and efficiently.
It is not rocket science, but you need a high degree of precision not to be opening a can of worms and have the current problem get amplified.

If I had a dollar for every DIY attempt at bolt extraction that went badly wrong, i could open my own machine shop.

I have an amateur machine shop in my basement....C/W a vertical mill....left hand drills in a few sizes....and I still take about half of my own "ooops' to a pro.

 

[interalian]

Do you mean one of the 1/4" cap screws that holds on the figure eight water jacket cover? I had a broken bolt there on my recent rebuild and it was a fun fix even with the head off. Glad it was only the one. Ended up drilling it but the drill went off center. Screw it, says I, and ran a tap along side the broken bolt. Enlarged the hole in the cover and it's fine. Not perfect, but fine.

 

[F_R]

One good thing in your favor--you broke it off while installing the bolt. That means at least it is not seized or corroded in the hole. A candidate for something I very rarely recommend. It probably will come out with an Easy-out, even though I despise them.

But yes, you must be careful not to allow the drill to go off-center. Anybody that is experienced in drilling out bolts knows that and how to avoid it.

 

[racerone]

I would not consider one of those 1/4" bolts broken to be a " big problem " as per the mechanic who said this ??

 

[MadtownChris]

To be clear the mechanic did not call it a "big problem," I did since he said they couldn't handle it and I had to take it a good distance away for the right expertise.

To be more specific, it's one of the bolts that holds part #29 in the attached diagram below to the block. The bolt is broken off just about flush with the block so not easy to access. It's not one of the smaller bolts holding that cover #31 on.

- Chris

 

[interalian]

Yeah, those bolts all need to be there. 29 is the head, 31 is the water cover. But as noted above, since you broke it during installation rather than removal, it won't be seized in place. Access to remove will depend greatly on where on the block. Unless you have a straight shot at it, you may have to remove the powerhead. Not a quick job, but not that hard unless you have a salt motor and then you risk breaking other bolts during disassembly.

 

[gm280]

First, can you actually see the remaining bolt? And if you can is it basically flat or an angled snap off? If flat, that is way better then angles. Of course the head can tell you that as well if in broke clean and not in a few pieces. If it is basically a flat break, you could try a long reach drill bit and drill a smaller hole in the remaining bolt. Then using a ezy-out, try to back it out. If it was just installed, regardless how much torque you snapped it off at, there is zero torque on it now. So it should back out relatively easy with an ezy-out. I would try it myself before removing the head. The worst you can do is not be able to remove it. Just take your time and drill slowly but centered as well. And yes they do make left-hand drill biits and that could work out great if you can buy one. I wouldn't be suprised to see it back out while drilling with a left-handed bit either. JMHO

 

[interalian]

If you can't see the angle of the break, the broken bolt may show you whether flat or angled. Do you have a straight shot at the hole or is it low and behind the motor pan?

 

[Tim Frank]

Missed the fact that you broke it while installing.
As suggested, that greatly increases your options AND chances of success.

One approach would be - if you know anyone who has a metal lathe, see if they would chuck up the broken piece and drill a dead-center through-hole...say 1/8".
Then use that piece as a drill bushing/guide do drill a 1/8" hole in the centre of the remaining stub as a pilot for a small easy-out.

 

[gm280]

Missed the fact that you broke it while installing.
As suggested, that greatly increases your options AND chances of success.

One approach would be - if you know anyone who has a metal lathe, see if they would chuck up the broken piece and drill a dead-center through-hole...say 1/8".
Then use that piece as a drill bushing/guide do drill a 1/8" hole in the centre of the remaining stub as a pilot for a small easy-out.

Tim that really is a good idea. Others could use that I'm sure. :thumb:

 

[jakedaawg]

Is the head removed? If so it is not hard to propery prepare a stud and weld it onto the bolt if it is broke flush or slightly protruding

 

[interalian]

A photo showing the location of the broken bolt would be helpful.

 

[boobie]

Get some left-hand drill bits and the bolt might pop right out. I've had good luck with them.

 

[Tim Frank]

Tim that really is a good idea. Others could use that I'm sure. :thumb:

I've done it a few times successfully.
The head can be held from spinning in a closed end wrench of the right size.

 

[MadtownChris]

Resolution...

Thanks for the help - as usual you guys are great! I took it to another mechanic who said there was a 70-80% chance he could get it out with an EZ out and if not he could put a helicoil in as a last resort (though pointed out that this is not a great option). He got it out OK, put in a new heat gasket, put everything back together, compression-tested and should be ready to go.

I think the first guy only does things with 100% chance of a perfect outcome. That's great if you have a $20k boat but a busted '78 outboard is a different story IMO.

Chris

 

[Tim Frank]

Gotta love the fairy-tale endings.

 

[gm280]

Bravo MadtownChris, Bravo. :cheer2:

Always great when folks come back and let other know the final results. Happy boating and be safe... :thumb: :thumb:

 

[jakedaawg]

I should have taken pics but today i had a bolt broke flush, no room for a drill without pulling motor. I used a nut smaller than the bolt, held it to the block and used the mig through the hole to weld from the inside. Put the socket on it and it backed roght out.

 

[jimmbo]

I'm surprised the bolt broke in the first place. All my experiences with Aluminium threads and steel bolts ended with stripped aluminium threads and undamaged bolts