How Do I Remove a Broken Spark plug on a 2012 Super Tenere?

Ritters Dad

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I changed out the original spark plugs at 12k miles recently. I used the recommended NGK CPR8EB9 plugs, put anti-seize compound on the threads and tightened them all the same. Bike ran well for about 300 miles then I started to hear the dreaded nondescript engine noise and uneven performance. After spending hours researching what this could be, I saw everything from loose battery cables to cam chain tensioners to throttle body syncing, throttle position switches, accelerator position switch.....you get the picture. I finally snapped out of data paralysis and decided to start with the plugs. I pulled the first 3 going right to left, all were in perfect condition, clean with white porcelain insulators. I had a very tough time pulling out the coil on #1. When I did get it out I was shocked to see the rubber boot fried and crispy. I was also dismayed to see the top half of the spark plug still in the grip of the coil assembly. In other words the threaded barrel stayed in the cylinder head. Not unheard of but a bit of bad luck.

So I have a broken spark plug with the threaded portion still tightly in the cylinder head with the central electrode and porcelain snapped off and intack.

Question: how in heck can I get the bottom half out without breaking the insulator porcelain and risking pieces of porcelain falling into the cylinder chamber.
Any ideas out there?
 
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Kyle_E

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Crap.

I know they make tools for this situation. I wonder if your local "auto zone" that does tool rental would have it for loan so you wouldn't have to buy it for that one in a life time use.
 

Don in Lodi

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Did the spark plug hex come off with the coil and just leave the threaded portion in the head? If the hex is still part of the remnants in the head you still use a socket like normal, you just need a magnet to pull the remnants out of the well. If the hex came off with the coil it gets much more tricky. If it's still a 'normal' removal, you should blast some air down the well to remove any porcelain bits before removal.
 
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Xclimation

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If the hex is still intact....then I'd first vacuum out the plug well....then while loosening the plug, every couple of turns pull out the socket and vacuum. Also, I'd try to have a vacuum suctioning out best as possible while loosening them after removal. If you can use some duct type tape and make a reducer (if you will) to attach a more narrow tube and even try to gently get into the cylinder. Good luck and let us know how it turns out!
 

Tenman

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Blow it out with air and if you have a endoscope look. endoscopes are cheap and good to look in your mouth for cavities
 

WJBertrand

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Unfortunately it sounds like that plug was cross-threaded when installed and didn’t fully seat/seal. That would explain the burned coil stick too. Sorry to say, but I’d be seriously considering pulling the head at this point.


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Ritters Dad

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Did the spark plug hex come off with the coil and just leave the threaded portion in the head? If the hex is still part of the remnants in the head you still use a socket like normal, you just need a magnet to pull the remnants out of the well. If the hex came off with the coil it gets much more tricky. If it's still a 'normal' removal, you should blast some air down the well to remove any porcelain bits before removal.
Hi guys, looks like I screwed the pooch (sorry doggies) on this one. I'm going to try the Ford Triton broken plug removal trick of epoxing a metal stud to the remaining central electrode and porcelain and hope I can pull the central pieces out then use a square removal tool to remove the threaded barrel. I'll post results.
 

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Don in Lodi

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If the epoxy bonds like it should, you might be able to turn out the threads... provided they are not in fact cross threaded in. Wrap enough tape around your tool/epoxy applicator so it will remain centered going down the well. It would be an added pain to have it glue itself to the head.
 

jbrown

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Wow. I've seen those long Ford Triton plugs break, leaving the non-threaded portion stuck in the head, but I've never seen a plug break the hex off, leaving the threaded part in the head. Is this likely due to a defective plug? Do I understand correctly that just pulling the coil out left the broken plug in place? So the metal was likely cracked from the beginning?
 

blitz11

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You beat me to it!! That's what I would do as well.
I'd give it the epoxy/Triton try first. if it doesn't work, then pull the head. You really have nothing to lose. i just checked my valve adjustment a few months ago, and i don't really remember how much room in which you have to work. (Becoming old sucks.) I DO remember pulling the front motor mount and that gave me more room.

That being said, I am unsure of the ability of the epoxy to pull the porcelain out of the metal. You could take a punch and a hammer and break the porcelain out bit by bit until it's loose enough to extract. you do run the risk of stuff falling into the cylinder. you could blow that which falls in out with compressed air. i am guessing that the electrode is ferrous - you could grab that with a magnet. (I'd check with the part of the spark plug which was in the coil to check that hypothesis.) if it's not ferrous, you won't be able to use a magnet, and it might be too heavy to blow out with compressed air.

Either way, good luck. Sorry that this has happened to you.
 

magic

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jbrown

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Since it broke in the threaded area, it might not take a large amount of twisting force to unscrew it. There is no clamping torque to overcome. Only the likely thread deformation, and carbon that may be built up on exposed threads in the head. It should be no where near what you need to unscrew a normal spark plug. I'd cram a screw driver in there and see if it will twist a little. If it moves at all like that, then you can figure out how to capture the fragments and hold on to it as you unscrew it.
 
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