Broken Spark Plug Extraction

Hello again, fine community.

I've been working on getting my new-to-me Silverwing running and hit a snag. As I was troubleshooting the spark plugs, the electrode shell (the threaded portion) broke off in the engine. I tried using an extractor from AutoZone, but it turns out that motorcycle plugs are smaller than regular vehicles', so that didn't work. I bought a square "easy out" from Amazon at the recommendation of internet instruction, but it was too short to be useable.

Do you fine folks have any recommendations for an extractor to use? I'd prefer one that's designed for motorcycle spark plugs, but anything that actually works (and won't make the problem worse) would be greatly appreciated.

Thanks in advance.

I'll ask a friend who knows everything.
Can you post a photograph of what you did get out so as we have an as exact as possible picture of what's left in.

https://www.mcmaster.com/products/screw-extractors/straight-flute-extractors-7/

I saw something like this as an extractor, but I’m not sure how deep in the head the spark plug threads are. I wonder if you can use this with an extension to unscrew the threads of the plug.

Also, as the plug broke, did any parts of it fall into the cylinder? Then you’re looking at pulling the head I would assume.

I feel your pain. I had a similar problem with a Tenere, that ended up with having to take the head off.

The plug size is a 16mm deep socket.

If the plug end is still screwed into the head blow out any debris with an air line before extraction.
Loosen the plug using a 3/8 x 16mm deep socket on an extension bar covered in mini magnets taped to it.
The magnets should make for a clean extraction of the lower part of the plug.

Hope this helps.

Be safe, be seen!

It would sound like the spark plug got torqued way too hard at some point. Perhaps put some penetrating oil in the cavity, let soak, then try JohnnyC's method above.

Use anti seize on the threads and do not over torque the plug. Good luck.

[url=https://servimg.com/view/20517987/1]

The part outlined in red is the only bit still in the engine. It's essentially a threaded pipe right now. Everything else came out in one piece.

I'll try something like what Erdoc48 recommended. The only problem is that the threads start 5 to 6 inches down into the head. I don't think anything got down into the cylinder itself, but we'll see.

Could someone host the image om here please, I can't access the image direct.
Manny thanks in advance.

Be safe, be seen!

I have 2 brief recommendations:
-if using anti-seize on the spark plugs, lower the reinstallation torque by ~ 20- 30%, so if the plugs require 9 ft-lbs of torque (you should check the actual torque value, but my 03 manual indicates 9 ft-lbs for the spark plugs), then drop it to ~7 ft-lbs, so as to not over torque with the anti-seize on the threads (and just a very little at that)- I recall using an inch-lb wrench when I did my plugs. Someone here did a pictorial for spark plug maintenance and they indicated their shop manual specified 16 ft-lbs, which sounds kind of high to me

-a magnet is a great idea if you can snake one through the spark plug hole- I would also use a bore scope (see if you can rent one) to get a good look around to make sure there’s nothing residually in the cylinder (and if there is you can try some compressed air to blow it out the spark plug hole)- you don’t want to fire that bike up with any foreign matter in there.

Best of luck with all of this- it’s frustrating but if you can correct this without removing the head, that’s a huge plus!

Let me see if the site likes this method better than OPs....




I've never heard of a plug breaking at the threads like that, I'd be concerned that there is ceramic from the electrode sitting on top of the piston.

Honestly, I still want to see an actual photograph of what came out.

I'd love to show what actually came out. Unfortunately it was a new plug being installed and I already swapped it for another new plug from AutoZone. The only thing left in the engine is the threaded bit. The employee I talked to for the swap was also surprised at how it broke.

I'll look into renting a bore scope as well. Fingers crossed that nothing is in the cylinder. This is the tool I decided to buy. It should arrive sometime tomorrow. I'll post an update once I've tried it out.

https://www.amazon.com/dp/B07BN5RY59?psc=1&ref=ppx_yo2ov_dt_b_product_details

OMG no way......!

If that "IS" all that is left in the head......it's a Head off job to check for debris on the piston anyway, and possibly a replacement Head because sheering the Hardened Metal rather than removing the Metal in an Ali head don't look to good for thread recovery, and would probably require the use of a Helicoil as a thread repair somewhere along the way but not the ideal place to use one having seen a Helicoil blow out of a Steel car head. And TBH I don't think you will get a Helicoil long enough.
Sorry to be a bit of a downer.
Maybe a good plan to price up a used head first.
Cover for the worst scenario. This repair has all the hallmarks for going south pretty quickly.
"Good Luck" also springs to mind.

Be safe, be seen!

Question? Plug broke off when installed? Old plug came out and you tried installing a new one?

Sounds like you cross treaded it going in not good. Head can be repaired if you get it out, I'm not a Helicoil fan on many repairs. Time-Sert is a better option but not sure they make it in that thread pitch and size. If in doubt have an experienced Mech look at it.

Pulling the head is a lot of work and parts not for the average person without Mech experience.

It's a Head off job. My tool came in today and now it's also stuck in the cylinder. I have the service manual and am working through removing the camshaft. I'm stuck on finding where the flywheel is and making sure that the piston is top dead center.

Assuming it's displaying properly, this is the step in the service manual that I need help with.




Thanks again for all the help.

Trying again with the picture

Mech 1 twa wrote:

I'm not a Helicoil fan on many repairs. Time-Sert is a better option but not sure they make it in that thread pitch and size.

I've a friend with a 1953 Manx Norton that has a helicoil in it from new (I knew the original owner). It was cross threaded in the factory and obviously nothing was said.

I have a Helicoil on the oil pan drain threads on my 2000 ST- they hold up just fine- never had a leak.