Spark Plug Broke in Head

[billsmarz]

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Been having some rough running lately (misfire on engine braking, no power, bad mileage). This happens after someone tried to steal it and it sat before I could get it back up with a new ignition…. Sorry this is another problem.

I was changing the spark plugs to the iridium. I get all the old plugs out no problem. Figured at 21k, it was time. I went in from the top instead of taking off the radiator. I figured I’d at least need to test the coils so they’ll be out anyway.

It was the last new plug I was putting in, four, on the far right. I threaded it in by hand with the extension and rubber socket. snugged up. Noodled the ratchet on and tightened. After a small tighten it started getting loose. I panicked and assumed I was actually cross threaded it.

I pulled it out and inspected. There didn’t seem to be any issue, but I was looking at the first few threads for damage, so I started to delicately reinstall. I assumed it was damage on the head threads so I wanted to see how bad.

It went right in, hand snug, then began to torque, and boom no resistance. Pulled the plug out and the ceramic and electrode came out leading the threads in the head!

I have theories for cause, most include some user error (cranking the thing in the hole, over tightening, etc) but I’m going to blame a faulty plug and focus finding a way to get compression.

I’ve read some people do this with an Easy Out. Leaving metal shreds in the cylinder is certainly a concern this route. It’s also probably impossible to get straight in too, tucked under the frame. This gets me to the actual question; Anyone think it’s worth leaving the engine in and giving it a go? Will the head come off without dropping the engine?



Backstory if you care:

This was me beginning to troubleshoot fuel and ignition issues. I assumed since it started and idled without problems it was either too much/little fuel or bad spark. The bike has 21k on it. I figured the fuel filter should be changed and plugs. Since I was in there l, I figured I’d order some coils just in case to have them to test. Still need to test, was putting plugs in during issue.

 

[Gary in NJ]

It looks like you can still get a socket on what remains of the plug. Using duct tape and some rubber hose, I would "MacGiver" a vacuum attachment to remove any derbies, losen the spark plug, and then use a magnet to remove the lower part of the plug.

 

[billsmarz]

Thanks for the insight. I think I can make a vacuum work. That leaves getting to the actual thread. The only part that remains is the the threads of the plug in the head. The third image shows the missing threads from the plug.

 

[Gary in NJ]

I didn’t look close enough on the third photo. That’s gonna be a problem. If there is enough of a lip protruding you might be able to remove that with a large screw driver, but the photo shows a fairly clean break. I think an EZ-Out will be your best bet. An extractor may make some metal shaving, so be sure to use your vacuum again…don’t be afraid to get inside the combustion chamber.

Do you have access to a borescope? I have one that I purchased on Amazon a few years ago and it has proven to be a very valuable tool. This would allow you to fully inspect the combustion chamber after the extraction.

 

[billsmarz]

Alright, rachet-attachable eazy out set ordered. Should know if I'm pulling the head this weekend.

Thanks for the help. Anyone know if I have to drop the engine to take the head off? Limited tools and would like to avoid. Or if anyone knows a shop in Philadelphia?

 

[Gary in NJ]

I think you will find that the extractor will work. The key for success will be to not over engage the extractor - this could cause the remaining threads to expand, locking the threads in place.

 

[bryancraftyhands]

I saw that square shaped extractors are not as likely to expand the parts to be extracted, over round shaped,if you have a choice.
If you need a shop, I've never had a problem with Philly Cycle Center on Castor Ave for anything I've had them do. I'd also give good props to Riderz Inc. in Erial Nj. There's East Coast and a Yamaha dealer on 13 around Street Rd, Liberty Vintage and Gino's in Fishtown, and Quaker City in Manayunk all have a good reputation. Otherwise, there's a bunch of shops that have sprouted up in recent years you can try, and report back with reviews. Some have been around for at least 2 years now, so they must be doing something right.

 

[billsmarz]

Thanks for help! The extractor worked and she’s back up and running! Tubing taped to vacuum hose cleaned as much as possible. Should probably change the oil for good measure.

I can also report I have perfected the extraction method… I didn’t take off the nipple(?) from the plug so the 3 plugs I installed previously needed to come out and go back in. After a second plug broke off I decided I couldn’t trust my torque wrench and borrowed a friend’s. 6 plugs later, everything is working.

I did seem to fix my rough running and backfire. A combination of new plugs, new (used) coil packs, and cleaning the fuel filter seems to have done the trick. I figured if I was going all the way in for the plug I might as well replace known maintenance things that were already coming out. And why not fiddle with more than one thing to really confuse diagnostics?

 

[Gary in NJ]

Excellent news. Well done.

 

[bryancraftyhands]

Can't hurt to change the oil, but if you left anything in the cylinder, it would be spat out the exhaust before it would get past the rings. Glad you got it.

 

[TownsendsFJR1300]

Glad she's been saved!