| Author | Message | ||
     Jessicasdad |
OK, going to work the other morning and BANG, Loud noise and bike sounds horrible. First thought was that I had blown out an exhaust seal, done that often enough in cars. Nope, turns out the the front plug was "blown out" of the motor. And now trying to get a new plug in I can see that the threads are pretty well stripped out. I was reading the manual and it mentions using a "12 mm Spark plug repair kit". Ok, my question to all of you is ... have any of you used this ?? and has this happened to anyone else and how did you repair it? Thank in advance ! | ||
| Davy_boy |
A heili coil kit would do the trick , not sure if I spelled it right ! this repair would make the treads stronger then original but the key is making sure you put it in straight . I have used them before and they work really well . Kits are very expensive but a kit for just one sized tread will cost you around 70 bucks . And the kits come complete will a tap and install tool . A good auto parts store will have them . good luck | ||
| New12r |
Dont helicoil it until you know they are stripped so far oversized you cannot repair them. I would run a chase tap to see if the original threads are good. Sometimes IF you are good you can use an old spark plug to clean the threads. The space is tight, I would roll the motor down for better access, If you buger this up it could get ugly. (Message edited by new12r on February 01, 2006) | ||
| Diablobrian |
I would not heli-coil it. Since you have to remove the head to do the repair right (you do not want the metal chips in your combustion chamber). I would look more toward finding a good machine shop to weld up the damage and re-tap it. Or a time-sert type of insert. these are solid steel and wont unwind, or leak-by during compression. here is a page that shows the time-serts... http://www.motorcyclecarbs.com/kl/catalog/2003/098.pdf | ||
| Lucas70374 |
You know the same shit happened to me awhile back, This is what I done, since I couldnt change my head right then. I rotated my engine, and installed a Time-sert (good recommendation Biablobrian) I didnt have to remove my head, Use Grease on the drill bit picks up shavings. Before I started drilling I rotated the pistions so the exhaust valve is open and after I drilled out the hole, I blow the little shavings that fell with a airgun out through the exhaust. It held up for a while but I replaced the head as soon as my funds let me replace it. Hope this helps you. | ||
| Rubberdown |
What would cause a plug to blow out of its threads? | ||
| Lucas70374 |
well mine didnt acutally blow out. I dont know if I didnt tighten it good or what but this is what happened. The plug worked its way out, and when a couple of threads are started, it is very loose and the bouncing around strips the threads. ALL I CAN SEE HAPPENED I am blaming myself for the screw up. This happened a long time ago, I made sure to change it before I went out of town | ||
| Diablobrian |
if it was cross threaded at some point the threads will be very weak. | ||
| Percyco |
So......what can be done to make sure this doesn't happen (stripped sparkplug hole) ? Should plugs be checked every so often to make sure they are tight ? PM Clark | ||
| Diablobrian |
well, first off always start threaded fasteners by hand, not with a wrench. if you need to use a socket turn the extension gently with 2 fingers to prevent cross-threading. Or better yet use plastic/rubber tubing placed over the plug to get it started into the threads. Torque to proper spec and you should be fine. It is very rare for a properly torqued fastener to come loose. On other fittings (not sparkplugs)use blue lock-tite to keep problem fasteners in place. | ||
| Starter |
Always using anti-sieze might be a good start. That way when screwing it in there is alot more feel and you'll know if there is a problem. Fingers only till it is seated. You will always get an accurate torque and the chances of the other common occurance of the plug seizing is avoided when using anti-sieze. There is nothing wrong with a helicoil, being certified for thread repair in aviation applications should tell you that. Correct installation is the main point to focus on. Taking the head off is not essential as metioned before greasing the drill and tap will catch most metal filings. A quick vacuum and a few cranks with the plug out will blow anything ealse out of the chamber. I had a GSXR with a seized plug and it was repaired with a heli coil whilst in the bike. Repair held fine and didn't feel any different in terms of thread quality to the other cylinders when changing plugs. | ||
| Diablobrian |
I'm of the opinion 1 chip that makes it into the cylinder is 1 too many.  I just don't like the idea of losing the motor because I took a short-cut. You cannot be sure to get all of them out without removing the head. I always assume people are using anti-sieze. didn't occur to me to suggest it. Good catch! | ||
| Jessicasdad |
thanks all ... I am planning on rotating the motor this weekend and doing a final analysis of the situation. But the hole was stripped out to the point that the plug was basically being held by the last couple of threads .. so I am thinking that a thread chaser will not cut it (yeah, pun intended) so I am thinking either the Heli-Coil or the Timesert will be the ticket. I too have used the Heli-coils in the past and they have held vacuum without any issues. But I am going to see how things look and feel when I run the bigger tap down the hole .. thanks again all .. I knew that I could count on all of you for sound advice and experience .... | ||
| Davefla |
I wonder if you could oversize by 2mm and use, what, a 14mm threaded plug? (That ought to also help with fouling, right? Can't imagine why the factory hasn't done it if it's that simple.) Anyone know of this mod being done? How would it affect the combustion chamber/compression ratio? | ||
| Diablobrian |
maybe a clearance issue with the valve pockets. Or a matter of strength because of the material that would be lost. I'm sure there are some people here that know. (Message edited by diablobrian on February 02, 2006) | ||
| Fullpower |
just clean up the threads, you only lost the last 2 threads, you should have PLENTY left. ( 3/4" reach plug) good luck. | ||
| Jessicasdad |
it is the other way around Fullpower .. I have only 2 or so good threads .. the rest are not even there.. I can basically slide the spark plug in and out of the hole .. I would estimate that the over all diameter of the hole to be close to 14mm given the amount of free play .. I am thinking that all of the vibrating or whatever actually worked to open up the diameter of the hole ..... planning on rotating the motor this weekend and going Timesert or Heli-Coil ... need to get back on it ... too much gas to keep the truck running ... | ||
| Dragonbuell12r |
I've always used Mobil 1 motor oil when changing plugs on the aluminum heads on my cars, trucks and bikes and havn't had a problem. The oil on the threads still looks like oil when I've pulled the plugs for a change. Does anyone think that doing it my way could cause a problem?? Thanks. | ||
| Skully |
Does anyone think that doing it my way could cause a problem?? I can't imagine that it would. I was also going to recommend the use of anti-seize that is O2 sensor compatible. It will say so on the package. Keith | ||
| Buelldyno_guy |
A&P mechanics use a special Helicoil kit made just for plugs and can be used on aircraft where there are no removable heads. ... But the front head is the easy one to remove. Put the rear wheel in a chock or lock it into the stand so you can jack the front. remove the muffler, and the airbox, disconnect the three tie rod links from the engine. Place the jack under the engine and support the engine. Remove the three allen screws from the oil cooler support sub frame. You should now be able to loosen and then lower the engine. when it's low enough remove the valve cover rocker box and then the head. Takes two hours the first time. ... Hope this helps. ... Terry | ||
| Johnk3 |
happened to me, the plug blew right out and stripped the threads. I had the head replaced under "warranty". The selling dealer who changed the plugs on more than one occasion refused to help. factory refused to cover it as warranty parts as it wasn't a defect. If it was for Dora, DaveS and Court I would have sold the Buell for all the frustration I went through. | ||
| Sparky |
How did you have the head replaced under "warranty" if the factory refused to cover it as warranty parts as it wasn't a defect? | ||
| Johnk3 |
I paid for the head to be replaced, $1200 total. I was compensated on the back end after some board members helped me out with the factory. The whole thing is a little •••••• up, and the story is pretty long... |
