HELP!!!!!...Cross threaded spark plug

[GS750GUY]

GS750Guy here again.
I was in the process of taking a plug reading a few days after I had been out for a long ride. Normally all four of my spark plugs will screw in nicely and almost to the bottom just using finger pressure and then I snug them up finally with the socket and wrench. This time I was in the process of hand starting my #3 plug, I felt the threads engange, and instead of several nice smooth turns to the bottom it suddenly after a quarter turn or so came to an abrupt stop. Thinking it was maybe some grit of some kind I tried a little harder with just my hand and fingers and still could not make the plug budge. I backed out the plug and tried cleaning the treads on the plug and in the head and still after many many attempts CANNOT GET THAT PLUG IN PLACE. My greatest fear was that I had begun to cross thread the plug.
I went to my local O'Reilly's auto parts store, told the oldest clerk there my story and he lead me to the tools rack and said here is what you need as he pulled a plug thread chase from the rack. His next comment could have been my clue that maybe I was using the wrong tool when he told me that if I start it straight it will do the trick. Well I thought after leaving the store that if I could start it straight I could do that with the plug and would not need the tool.
Anyway, thinking he knows more than me I went home and tried using the tool only to find out that I may have made thing worse by using it. It appears I may have only buggered up the first one or two threads before I stopped using the tool. I could not get it to start straight for some reason. Or maybe I'm using it incorrectly.
Does anyone out there have any suggestions? Should I be using a tap instead of a thread chase?
I should have consulted my trusty GS site first before going to work on this.
Thanks for your advice!
Gs750Guy.

[Mellow'dOut]

http://www.thegsresources.com/_forum/showthread.php?t=125153

[spyug]

Sorry to hear of your predicament, I've been through it myself with the same plug.

Just when i had the bike in for certification after i got it last year. The mechanic noted the plug was cross threaded and that as the plug was not seated properly the firing was a bit off. They considered that a deficiency and wouldn't cert the bike 'til they fixed it $200 later. They had me on that one.

If you are able to find a tap of the right size ( and i don't know what that is sorry) you might be able to recut things. I do doubt it though and I suspect you will need to have the hole drilled and heli-coiled as I had to have. Luckily, they were able to do it with the head still on the engine or it would have cost double I'm sure.

I hate being the bearer of bad news and I hope you can sort this with a tap.

Good luck to you and let us know what developes.

cheers,
Spyug

[jadesystem]

A thread insert, or the brand most famous for this tool, is HeliCoil.
You will select a drill bit that is closest to the insert ID but not over
the OD. Drill-out the stripped plug threads for the insert thread HeliCoil
Tap. The tap will make new theads that will accept the new Heli-Coil
for your sparkplug threads.

Once the hole is redrilled and tapped, you insert the Heli-Coil insert
with a special tool. It will allow you to drive the new heli-Coil in-place
with a crank and to snap the tang which allowed you to leverage and
grasp the insert in the first place (with the tool).

But you do not want to simpley drop the tang into the cylinder. You do not want any metal to fall into the engine. I think there is a special tool
for this. As in most cases that are non-critical, you merely push the special tool and the tang breaks off. It breaks off very easily as it is
pre-deformed with an indentation.

I've never has this problem before, and hopefully you do not have to
take the head off, which is worse case. I always use a few drops of
10-wt machine oil for all my new plug threads when swapping out plugs.
And I go very easy as not to cross thread it.

The Heli-Coil comes in a kit or you can buy individual taps and inserts.
I have a few complete kits such as popular metric M2.5, M3, M4, M5
but notning in your size of a spark plug thread or I would gladly send
it to you as a free loaner.

Good luck to you,

KT
San Jose, CA :-D\\/








next therad

[yhprum]

There is also a thread chasing tap for spark plug that is adjustable, so it collapses slightly so you can get past the bad threads. Then you open it up and unscrew it and hopefully your done!

http://www.tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=28366

Good Luck! Steve

[Kbecker3]

here is one me and my friend used on his bike after he boogered up the top 2 threads.. it worked great, almost all of the shavings from the re-cut threads stayed on top of the tool, just used an air compressor to shoot them out of there before we removed the tool..

worked great!

http://cgi.ebay.com/Snap-on-BLUE-POINT-12mm-Spark-Plug-Back-Tap-SPHR3-NEW_W0QQitemZ310049939817QQihZ021QQcategoryZ20773QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[GS750GUY]

Thanks guys for all your help. I GOT IT FIXED!!!!
What I did is I took the $7.00 spark plug chase that was boogering up the first one or two of my threads even worse and created my own tool that worked beautifully.
I thought if there were a way to get to the good threads at the bottom of the plug hole and back out I could then use the good threads as a guide to straighten the bad threads at the the top of the hole.
So I took the thread chase tool and clamped the socket end in a vice, heated it to loose its temper so I could cut on it with a new hack saw blade and I then cut two vertical cuts creating a wedge in the center the length of the tool slightly larger than the taper of my largest flat screwdriver. I then took a small drill bit and cut a shallow vertical hole in each of the remaining outside halves that contained the threads. I then 5 minute epoxied about a 12" piece of coper wire in each hole and let it dry. After drying I then mounted the tool horizontally in the vice and finished cutting the outer halves off of the tool leaving the center wedge shaped piece of steel on the tool.
What I had created then was two seperate moon shapped threaded pieces of tool with a length of copper wire to be used as a guide and handle. I then greased the threads on the tool real well and by holding onto the wire I inserted each half into the plug hole, lowered them to the bottom of the hole and evened them up with each other. I then took my largest flat screwdriver and inserted it in the wedge shapped space between each half forcing the threads of the tool into the good threads at the bottom of the hole. Then with a crescent wrench I locked onto the squared off end of the screwdriver up by the handle and began backing out of the hole working the tool back and forth in the hole as I backed out. It took a while to do, but was able to back clear out of the hole in this manner.
I then removed the tool, cleaned up the threads and using just my fingers I inserted the plug and began turning....... I was exstatic when I found I was able to easily find the new good threads and turn the plug clear to the bottom with just my finger pressure and finished it off with the socket and wrence. IT WORKED BEAUTIFULLY.
I was able to reconfigure my $7.00 tool that would not work into a tool that would finally fix the job.
GS750GUY

[catbed]

so basically you cut the thread chaser in half and wedged it in the hole with a screwdriver? just to simplify it a bit.

[GS750GUY]

so basically you cut the thread chaser in half and wedged it in the hole with a screwdriver? just to simplify it a bit.

Exactly,..........I tend to get a little long winded with my explanations sometimes. But I wanted to be a little more detailed just in case someone else may want to try it.
GS750GUY

[doctorgonzo]

I have one I need to do. The the threads are toast near the bottom. It threads ALMOST all the way in, but catches a few mm short of fully seating. I just run it that way for now, can I not just run a tap in there since it's ok at the top... recut the threads at the bottom.

[rapidray]

I have one I need to do. The the threads are toast near the bottom. It threads ALMOST all the way in, but catches a few mm short of fully seating. I just run it that way for now, can I not just run a tap in there since it's ok at the top... recut the threads at the bottom.

YES! Do EXACTLY that & you will be good to go! To the inventive guy above who modified his tool & OVERCAME his delima, I salute you for ingenious thinking! GREAT job!!! Ray.

[GS750GUY]

YES! Do EXACTLY that & you will be good to go! To the inventive guy above who modified his tool & OVERCAME his delima, I salute you for ingenious thinking! GREAT job!!! Ray.

Thanks Ray! I'm always looking for a way to save a buck and besides that part of the fun is trying to get creative with solving these kinds of challenges.
GS750guy