broke bolt off in head

Troutkiller2006 · #1 05-26-2016, 09:27 PM

i broke the top port side thermostat housing bolt in the head of my merc 225 2stroke, damnit! when pulling the motor off my chapparal so i could use it on the dually im getting that bolt looked like a good spot to secure the lift.when loosening it it turned maybe 1/8 of a turn before it snapped.

im seriously considering letting it slide and running the motor as is. its a 97 3.0 liter and that thing been on there a long time. i think if i keep an eye on it worse case it might leak a little but i dont think it woud put the motor in any danger if it does. and if it does leak i can deal with it then.what do you guys think?

SkunkBoat · #2 05-27-2016, 08:06 AM

you might get away with liquid gasket.

I just went thru a bolt removal problem with 2 bolts that were structurally important.

I tried a set of spiral screw extractors with no luck. Ended up taking it to a machine shop.$180

phatdaddy · #3 05-27-2016, 05:05 PM

Beware of ezzouts or what ever you call them. Once your break them off, your in deep dodo

Troutkiller2006 · #4 05-27-2016, 10:16 PM

thanks guys. never broke the seal on the thermostat housing. was just trying to take the bolt out to hook a chain to the motor. my gut tells me that it will be fine but i should keep an eye on it. my concern is am i putting my motor at risk? if it does leak will it really hurt anything, so long as i catch it quickly?

smokeonthewater · #5 05-27-2016, 10:23 PM

Depends on whether it leaks or LEAKS....

If the housing cracks and breaks you could be in bad shape FAST

THEFERMANATOR · #6 05-27-2016, 11:20 PM

If you can, post a pic. A picture is worth a thousand words as they say. From a picture, we can tell you if it looks like it's in a spot where it will leak, and if it does leak, will it leak on something important that it SHOULDN'T leak on.

scook · #7 05-28-2016, 01:01 AM

I got a kit called TapOut (some acid and a gob of clay) at a machine supply place when I broke a bolt in my I/O engine. You drill out as much of the center of the bolt as you can, build a little dam around the bolt and fill it with acid. When the acid quits bubbling you change it (if you can't tip the thing upside down to dump it out, you can soak it out with a cotton swab). It took a while but it got the job done. Since you never get the hole exactly in the center of the bolt, it'll usually eat through one side and you can probably worry it out of the hole at that point. The acid eats steel but doesn't damage aluminum - as long as you can keep it away from any iron you don't want eaten, you're in good shape.

Destroyer · #8 05-29-2016, 12:24 PM

Petty much everyone has been there, that gut wrenching moment when you snap off a bolt, or even worse, a tap into your crankcases or some other expensive and hard to replace part. I always had a bear of a time removing things like taps and bolts. Maybe I'm just a little ham fisted or maybe I just don't have (and won't pay) for the right tools. Well luckily a little science solves all our problems.

You can dissolve ferrous metals out of non-ferrous metals (such as aluminum, bronze, etc.) with alum (potassium aluminum sulfate). It's a sour tasting pickling spice sold at grocery stores (try your local food co-op) that helps crisp pickled vegetables.

Submerge the offending part into a pyrex (Heat resistant) dish (you don't want to do this in a steel pot!!!) full of a solution of 4 tbsp alum to 1 cup water (as much as you need to completely cover the bolt hole), I then placed the pyrex dish into a pot full of nearly boiling water and let it go. Heat is ESSENTIAL, or the alum won't dissolve. You'll see the steel part start to bubble a little bit (it's letting off pure oxygen) as the alum goes to town.

This isn't the fastest process in the world, it took me about 12 hours before enough of the tap dissolved to get it out. You could probably drill out the center of a bolt to help remove the bulk of the metal and then use the alum to dissolve away the rest leaving perfectly preserved threads. You can also either let it go until the part is completely dissolved, or you can speed things up by breaking little bits off with a sharp pick every hour or so.

The real draw is that there's relatively minimal labor involved, it's really cheap ($3 per application), totally safe and odorless (let the solution get cold and the alum will form into big crystals you can just save or throw away), and really hard to mess up. Plus if your threads in the piece aren't already ruined, they will be perfectly preserved!

As far as TapOut goes, as far as I can see it's primarily made of Nitric Acid. Very scary stuff. Nitric acid is very dangerous! It is highly reactive and can cause numerous reactions that end with an explosion. Another concern I would have is heat getting to residual acid on the part, as the fumes are poisonous. Considering all that, I'll stick to a drill or the Alum.

Still, since you can legally buy it I guess that with the proper precautions it might be ok. But again, for me, I'll use the Alum.

Troutkiller2006 · #9 05-29-2016, 09:04 PM

thanks for the tips guys. im nervous to even type nitric acid, much less buy some. shame though, that stuff and a little fertilizer... big fun. in a more perfect world the department of alcohol, tobacco and firearms would be a convenience store. that other stuff might work. but unless i could find a big dish, id have to take the head off. i'll just watch it and see if it leeks