Broken intake manifold bolts

I have a 1982 xj650 Maxim and while trying to install new intake manifold boots I broke a couple of the Allen head screws, and two screw extractors while I was it, plus I unsuccessfully tried to drill out the last one. Next trip is to the machine shop. Please tell me there is some hope.

 

Lots of hope. Machine shop will fix that right up

 

Alum in warm water dissolves steel, but not aluminum. You'll need some modelling clay too.

 

Thanks for the support, and I didn't know about the alum (ammonium aluminum sulfate); supermarket spice section?

 

yes spice rack

 

If your engine is out of the frame you could also try the Nitric Acid trick. I have extracted three broken exhaust studs + one of them had a broken reverse drill in it. It took me 8 -10 hours to dissolve all the studs. Machine shop is ok, and it will take definitely less time to deal with it, however you might need to remove the cylinder head to work on it. If you're not planning to rebuild your engine, it will cost extra money to replace the gaskets. Below it a recipe for the nitric acid solution that I found and used myslef.

"This recipe has been used to remove broken taps from aluminum and stainless steel (300 series) with success in the past. Your results may vary.
Important- Follow these instructions carefully since you are dealing with dangerous chemicals. If the chemicals are mixed in the wrong order an explosion may result. The author is not responsible for any injuries or damages caused from using this information. Anyone mixing or handling these chemicals is cautioned to proceed at their own risk. Always wear safety glasses or a full-face shield (preferred), wear protective clothing, and work near a source of water to flush any chemicals from your body if needed.
Pour 50 cc of concentrated Nitric Acid into a clean glass beaker. Dissolve a small scrap of copper in the nitric acid (approx ¼ inch diameter X 0.032 inch thick).
In another clean glass beaker add 250 cc of cold water. Slowly add the nitric acid/copper solution to the water.
Add 1 teaspoon of Ammonium Persulphate to the water/acid solution and stir with a glass rod until dissolved.
Clean all oil and grease off the broken tap with solvent followed by Acetone. Allow acetone to evaporate, then rinse thoroughly with clear water.
If necessary form a dam around the broken tap with modeling clay. Fill the hole with tap dissolving solution to cover the broken tap. The solution should start bubbling in a few seconds. It may be necessary to activate the solution by touching the immersed tap with a clean copper wire and scratching for a few seconds. The tap should be dissolved within 12 hours, and may be etched small enough to remove in less time. Heating the metal part will speed the rate of removal, but use caution not to reach the boiling point of the liquid.
The remaining solution may be stored in a sealed glass container for a few days, but may lose its effectiveness if stored for long periods of time."

 

Does the potassium aluminum sulfate work the same?
That variety is more readily available here.

 

Yes.

 

I know this thread is a month old, but how much Alum do you dissolve in warm water and how long does is usually take? I think I'm going to try this to get out the drilled out broken intake bolt that I broke last year.

 

there is a you tube video on this it takes a few days

use a few tablespoons it depends on how much water you use.

mix in as much as will disolve

 

I tried a couple of methods, I couldn't get alum, from spice rack section over here For some reason, ended up trying to get alum from a styptic stick, that didn't work much. Then I tried sulfuric acid, the one used in batteries, that weaken the bolt enough to get out the broken extractors. Since it was a dead end bolt hole I ended up drilling, retapping and using a helicoil.