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Removing a sheared spark plug

Posted: Tue Jan 06, 2009 4:43 pm
by WingAdmin
Last November, I took my GL1100A out for one last pre-winter ride, a toasty 38 degrees outside. Once I got it home, nice and warm, I drained and changed the oil and filter, and pulled the plugs. I squirted oil in the cylinders, and put the plugs back in - and as I torqued the first one, I thought; "this feels like a bit more than it's supposed to take" - just as I felt it give.

After lots of swearing, I pulled the socket out, and the top half of the plug (including the center electrode) came with it. That part of the plug had separated from the bottom half of the plug (the part with the threads, the side electrode, and the center ceramic insulator). The bottom half remains screwed securely into the block - thankfully it was the plug that gave way, and not the threads in the block.

I tried a couple things to get the plug remains out of the block, without luck.

I was very hopeful that I would be able to back it out without dropping anything into the cylinder. Looking at the plug, the threaded part that remained threaded in the block had about 1/3" of metal exposed, below which was ceramic. I did not want to get to the ceramic and potentially shatter or create ceramic dust which would then drop into the cylinder.

With that in mind, I went to NAPA with the top half of the plug and bought a square extractor whose end looked like it was just about the size of the upper ceramic sleeve that fit inside the metal threaded portion. It did fit - just about perfectly. However, it was so short, once I seated it into the threaded portion of the plug in the bike, I couldn't turn it - the top of the extractor just barely reached the top of the plug well.

I used a "fits any nut" spring-loaded socket that I bought ages ago and have never used, to fit over the end of the extractor, then put my socket wrench into the socket:


With much trepidation, I started applying pressure, feeling the extractor dig in, and then...I felt it release. I immediately removed the socket, and turned the extractor with my fingers until I had backed out the threaded portion of the plug, which came out with the extractor:


Nothing broke, nothing fell into the cylinder, and my bike is now sporting four brand new plugs.



Re: Sheared spark plug

Posted: Fri Feb 26, 2010 10:57 pm
by WingAdmin
This is just a reminder - when changing your plugs this spring, use a torque wrench!

Re: Removing a sheared spark plug

Posted: Mon Jun 10, 2013 1:31 am
by dondons1984
Had this happen to me also. Mine broke literally right at the nut so when I pulled out I had the nut and nothing to grab with since it was solid. I put in a screw extractor tapped it into place with a hammer and twisted. came right out but for safety sake I also took my head off to make sure I had no debris in it.

Re: Removing a sheared spark plug

Posted: Mon Jun 10, 2013 3:16 am
by BigDee
Bought a 500 Yamaha twin that was a literal basket case. It had a plug like that already broken. I did just about the same thing, only I welded an extension on the ez-out. Had to use a torch for heat and a 6 ft. cheater bar to break it loose. Thought I had broken the head at first but the plug did come out. When I finished putting the bike back together that machine could scream!

Re: Removing a sheared spark plug

Posted: Sat Oct 12, 2013 11:22 am
by Maddogg
Ok, I know this is probably a stupid question, but I am known for asking them anyway. Does the GL 1500 have 4 plugs or 6? WingAdmin said he had 4 new plugs but I thought the 1500 took 6. I haven't opened mine up to change plugs yet, (winter project for when I do my timing belts at the same time). When I looked at the timing belt how to article, it said I needed 6 plugs, so that is what I bought.

Re: Removing a sheared spark plug

Posted: Sun Oct 13, 2013 2:27 am
by BigDee
The 1500 has six plugs, WingAdmin had an 1100 before. It has 4.

Re: Removing a sheared spark plug

Posted: Mon Oct 14, 2013 10:19 am
by Maddogg
Ok, thanks BigDee, I appreciate the info.

Re: Removing a sheared spark plug

Posted: Tue Oct 15, 2013 10:54 am
by Fatwing Chris
OK I'm gonna get on my soapbox for a minute.Glad you got it out Scott,but that to me is just one more reason not to keep removing and replacing old plugs.I know people like to tinker with their bikes and their spark plugs.Cleaning,adjusting etc...,but spark plugs for the most part being dirt cheap if I pull them out there are new ones going in.You have a better chance of ruining your plugs(cracking porcelain etc..)by running them in and out.Same with the outer stainless steel housing because they are so thin to start with.So if I think my mileage is suffering or if it seems to be developing a miss I wouldn't regap and reinstall to try and cure.If they come out new ones are going in.
As far as putting oil in the cylinders for storage,storage oil sprayed into the intake of a warm engine will put a better,more uniform coating of oil on the engine internals and no plug removal.Quicker,easier and does a better job.

Sorry if I stepped on any toes,but I had to throw in my 2 cents here.

Re: Removing a sheared spark plug

Posted: Tue Oct 15, 2013 5:25 pm
by WingAdmin
Fatwing Chris wrote:OK I'm gonna get on my soapbox for a minute.Glad you got it out Scott,but that to me is just one more reason not to keep removing and replacing old plugs.I know people like to tinker with their bikes and their spark plugs.Cleaning,adjusting etc...,but spark plugs for the most part being dirt cheap if I pull them out there are new ones going in.You have a better chance of ruining your plugs(cracking porcelain etc..)by running them in and out.Same with the outer stainless steel housing because they are so thin to start with.So if I think my mileage is suffering or if it seems to be developing a miss I wouldn't regap and reinstall to try and cure.If they come out new ones are going in.
As far as putting oil in the cylinders for storage,storage oil sprayed into the intake of a warm engine will put a better,more uniform coating of oil on the engine internals and no plug removal.Quicker,easier and does a better job.

Sorry if I stepped on any toes,but I had to throw in my 2 cents here.
I have to concur with you absolutely - for all the trouble that caused, and for how cheap plugs are, I just buy new ones when I pull old ones out now.