Topic: cross threaded spark plug

[coke]

well, i really messed uptoday.. I cross threaded the #4 spark plug.  any suggestions.. I did a search on the forum and came up empty

thanks

[CycleRanger]

You may be able to carefully chase the threads with a tap. That's what I'd try first.
Otherwise you'll need a heli-coil.

Either way, pulling the head would give you the most control of the outcome.

[coke]

thanks, should I run the tap from the inside out after I take off the head?  I don't really have that plug in too far, so I think maybe there would be enough threads left towards the bottom to accommodate the plug

[lucky]

A case of TOO much coke?? LOL..lol

Quote:
"cross threaded a spark plug but rode the heck out of it on the relay leg anyway.. still running.." from WHAT I DID TO MY BIKE TODAY thread.

There is a special spark plug or tool that you can screw into the spark plug hole.
Ask at the auto store.

[lucky]

thanks, should I run the tap from the inside out after I take off the head?  I don't really have that plug in too far, so I think maybe there would be enough threads left towards the bottom to accommodate the plug

Yes that WOULD be the best choice if it is just the threads at the top.
Question is, what about when you are putting in a new plug in the future?
Will it get started correctly ?

You always start spark plugs by hand right?
Just asking.

[coke]

LOL about the too much coke.. must have been.. I did try starting by hand but it seemed tight and I used a tool. guess I was the tool.

[Old Scrambler]

Best is the 'from inside the head' with a tap......BUT.....if your good and steady, slowly run a NEW plug into the threads while attempting to hold the plug as straight as possible. Only use your fingers for the first full turn. If the plug remains straight, you may need a plug socket but only use your fingers to get another turn. If the plug does not stay straight, back it out and get some more wrenches.

I have done this more than once over the years on 736 and 305 motors with good success.

BTW......if you need to replace the threads, a Time-sert is stronger and longer lasting than a heli-coil.  A good shop should be able to install #1 or #4 without pulling the motor.

[Gman]

In another spark plug thread, another member (one of the old timers I think) gave a tip to use a piece of tubing over the end of the spark plug to help you "hold' the plug and get it far enough down the hole to get it aligned and started properly.  Pretty good idea, I thought, although it's a bit late for this go-around.  Next time! 

Good luck w/your fix.

[bender01]

Off topic.. Was looking at an ebay bike 2 days ago. Searched the sellers purchases and sales.. third or fourth thing up was a helicoil set!  Made me scrutinize the bike more. Search came up empty? I think the search function is still broke It went from great to ok to broke!

[scottly]

You need an expanding thread chaser:
http://www.amazon.com/KD-Tools-Back-Tap-12-Millimeter-Re-Thread/dp/B000NOX3KW

[nayto550]

You need an expanding thread chaser:
http://www.amazon.com/KD-Tools-Back-Tap-12-Millimeter-Re-Thread/dp/B000NOX3KW

+1!  I'm always leery of using a tap on pre-existing threads, especially in aluminum.  Those taps are sharp, and if the tap happens to get cocked up in the thread it will probably be to late to salvage by the time you notice (hello helicoil).

[camelman]

I bought an expanding thread chaser for this exact issue a while back. My spark plug hole was really buggered too. The tool easily fits in the hole, then slowly expands to seat into the good threads as you tighten it down. Back it out slowly and you're back in business. Cheaper than buying replacement gaskets and much faster!

[faux fiddy]

I've had luck using an old spark plug with a slot cut perpendicular in the threads along the length of the plug. It cleaned up some of mine that were  slightly  buggered.

Going from the inside is not a bad idea, either.

[matt mattison]

I just had this happen to me a month ago.I bought a 12mm  tap ( be sure to confirm the thread pitch) and carefully and slowly run the tap through. Make sure the piston is down in its bore. Afterward , I rigged up my shop vac with some tubing to suck out any alumimiun shavings. I didn't use any oil on the tap because cleaning out the shavings later might be a pain. Use the kicker, with the plug out, and turn it over a few times to blow out whatever what was missed. I did all this in about a half hour and never had to remove the head. Results may vary.

[trueblue]

This doesn't help you in this instance, but I keep a 10" piece of 1/4" fuel hose in my toolbox for starting sparkplugs in hard to reach  areas, just slip it onto the top of the plug and screw it in, once it is started in the thread then slip the socket onto it and tighten it up.  Using the fuel hose makes it imposible to damage the threads from crossthreading.

[bollingball]

This doesn't help you in this instance, but I keep a 10" piece of 1/4" fuel hose in my toolbox for starting sparkplugs in hard to reach  areas, just slip it onto the top of the plug and screw it in, once it is started in the thread then slip the socket onto it and tighten it up.  Using the fuel hose makes it imposible to damage the threads from crossthreading.

+1 trueblue  Also the expanding thread chaser is the best with it the chips are pulled out not pushed in. Taps are for cutting new threads not repairing screwed up ones. But I have done it when younger.
Ken

[coke]

I know this is going to sound a bit hokey.. but last night I was thinking.. some one should invent a device that you place down in the threaded hole and then it expands and you bring it out.. I had no idea that existed but i was figuring that would save having shavings in the cylinder and save having to take the heads off..   so much for getting rich on an invention.. LOL but I am glad to know they exist and I plan to pick one up and give it a go.. if that works it will save me a lot of time and trouble.. thanks for the heads up on that guys.. also.. I will be carrying a piece of tubing with me from now on too..

I am not going to work on it until I get GZ to Tulsa for the hand off.. it is still working right now and I just have to finish that leg of the relay before I start wrenching on the bike...

Again.. thanks a LOT

[lucky]

LOL about the too much coke.. must have been.. I did try starting by hand but it seemed tight and I used a tool. guess I was the tool.

I am sorry to hear about that. When you start spark plugs always make sure it screws in 4-5 threads nicely.

IF you just think it is the top threads i would take the head off and use a tap from the inside.
VERY IMPORTANT .... You must start the TAP by hand and it has to start right NO RESISTANCE otherwise it would just cut new thread over the old threads and then you WILL need a time sert.

[Mainerider]

At the mc shop where I work we always use Helicoil's sparkplug kit. It is designed specifically for plugs and has a special piloted tap- no drilling needed and the head can stay on the bike.   Here is just one link for reference; if you do order the kit from somewhere, make sure you get the correct thread pitch.

http://www.jbtoolsales.com/Helicoil-5523-10-Thread-Repair-Kit-for-Spark-Plugs-10mm-x-1-00-with-Tap-Installation-Tool-and-24

[CB500_k2]

I recently landed in the same situation.  I did not tease the #1 plug in properly before I used a wrench.  It went in but did not feel right.  I got a thread chaser on Amazon and it worked very well. Start it in with your fingers to be sure your are in the threads properly.  If the threads are really trashed a helicoil may be the only solution.  I used this first since I recently had the head off and I did not want to do it again if I did not have to.  It is a good idea to use a bit of anti sieze to assure a clean result.  In my case the results were very good and I can screw the plug down with fingers.

[lucky]

I recently landed in the same situation.  I did not tease the #1 plug in properly before I used a wrench.  It went in but did not feel right.  I got a thread chaser on Amazon and it worked very well. Start it in with your fingers to be sure your are in the threads properly.  If the threads are really trashed a helicoil may be the only solution.  I used this first since I recently had the head off and I did not want to do it again if I did not have to.  It is a good idea to use a bit of anti sieze to assure a clean result.  In my case the results were very good and I can screw the plug down with fingers.

Very good info and photo of the tool!!

[splitt]

I just had this happen to me a month ago.I bought a 12mm  tap ( be sure to confirm the thread pitch) and carefully and slowly run the tap through. Make sure the piston is down in its bore. Afterward , I rigged up my shop vac with some tubing to suck out any alumimiun shavings. I didn't use any oil on the tap because cleaning out the shavings later might be a pain. Use the kicker, with the plug out, and turn it over a few times to blow out whatever what was missed. I did all this in about a half hour and never had to remove the head. Results may vary.

I've heard of others using this method. Thoroughly grease the thread chaser first. (the grease is supposed to catch the shavings before they fall into the cylinder)

I always removed the head, but next time I'm going to try this method.

[Roach Carver]

One bit of advice i would like to add from my experience. If yo do any of these procedures withthe head on, hook a vacuum up, set to blow and put it on the exhaust port with th exhaust open. You can just tighten the valve if the piston position worries you. Just remember to put it back. This will blow most of the metal in your face so safety glasses are a must.

[trueblue]

A small piece of tubing that fits down the plug hole attached to a shop vac with some duck tape also does a good job of cleaning out any unwanted nasties

[Roach Carver]

A small piece of tubing that fits down the plug hole attached to a shop vac with some duck tape also does a good job of cleaning out any unwanted nasties

I think doing this also is a good idea but I would rather keep it out of there in the first place. I would do this after to pick up as much little crap as possible. No matter the method its sure to leave a certain amount of crap in the cylinder.