| Author | Message | ||
     Hoover_uly |
Doing a little maintenance yesterday, I also stripped some of the threads from the rear spark plug hole. I tried to remove the rear plug and it was very difficult. Turned it out about an eight of a turn or less and started soaking it with PB blaster. Worked it in and out and repeatedly soaked it. Went to the auto parts store and picked up some liquid wrench. Soaked it/worked it and let it sit several times. Did not really help. Put it together and started it to get it hot. With the engine hot, it was much easier to remove the plug but it was still somewhat difficult to turn. I kept soaking with liquid wrench and working it back and forth. At this point, I assumed all would probably be OK since it was turning easier and I kept it soaked with oil. When I finally got the plug out, it was covered in oil but, unfortunately, there are threads from the head stuck to the plug near the electrode end. I tried to remove the aluminum from the plug with a fairly stout dental tool and it will not budge. Broke the tip off the tool. It is as if it is fused to the plug so I don't think it happened as I was turning it out. It actually looks like there is solder in the threads of the plug. My plug looks similar to Goodburbon's ("I killed it post")in the way the material appears to be fused to the plug (center of threads) but the damage is not nearly as severe. I chased the threads with the front plug after I used a file to cut a groove in it to act as a tap. Used grease to collect any metal but it looked fairly clean. Quite a bit of thread left but it's not pretty. Put a light coating of anti-seize on a new plug, it threaded in easily and torqued to 18 lb. The bike has 5,000 miles. I purchased used and the plugs could be original. I was very careful and do not see anyway I could have avoided damaging the threads. I don't see how this could be carbon deposit related either. I considered just leaving the plug alone but I assume the damage would only be greater the longer it stayed in there. I guess I'll only be able to trust the bike when I can put an insert in but will ride it locally for now. Good luck with your spark plug maintenance. I don't see any way to avoid this kind of damage, at least on my bike. | ||
| Uly_man |
I would say you did a good job Hoover_uly. If you have over 50% threads left in the head it may be ok as well. Sometimes it is a good idea to let the fluid soak through the threads for a few hours or even over night for best results. This is a good example of how to work on bikes. Top marks and you may have saved yourself a big bill/problems as well. | ||
| Teeps |
Uly_man Posted on Monday, October 21, 2013 I would say you did a good job Hoover_uly. If you have over 50% threads left in the head it may be ok as well. Until the next plug removal. I suspect that carbon will build up on the exposed threads of the spark plug. Making in nearly impossible to remove short of using an EDM device... | ||
| Uly_man |
"Until the next plug removal. I suspect that carbon will build up on the exposed threads of the spark plug. Making in nearly impossible to remove short of using an EDM device..." Yes it could be a problem later on. Maybe you could "run the plug" every 5k or so to see if it helps any. But what else can you do apart from spend lots of money. | ||
| Sagehawk |
when you have heads off of motor, tighten plugs in, and see how far the threads protrude into cylinder. for my flhr, i used indexing washers more to space plug out of combustion chamber than to index the plug. no threads protrude into chamber and no carbon deposits on plug to take head threads out when you remove plugs in the future. a little bit of work but one less headache for normal maintenance. Stay with same brand of plug tho. | ||
| Hoover_uly |
Uly_man Posted on Monday, October 21, 2013 Sometimes it is a good idea to let the fluid soak through the threads for a few hours or even over night for best results. I spent around 4 hours or so screwing around with the plug. A good bit of that was allowing the plug to soak. Yes, it may have helped to allow it to soak longer but patience is a virtue I do not seem to possess. Since it would turn out so little in the beginning, I wondered if any oil would actually pass the crush washer. Teeps Posted on Monday, October 21, 2013 Until the next plug removal. I suspect that carbon will build up on the exposed threads of the spark plug. Making in nearly impossible to remove short of using an EDM device. Agreed. It looks like about 4 threads were pulled out of the bottom of the plug hole. At least that is where material was stuck to the plug. This can't help. I don't have access to equipment to allow me to closely inspect the remaining threads. I am also not familiar with an "EDM device" but I'm sure I don't have access to that either. Feel free to enlighten me... Sagehawk Posted on Monday, October 21, 2013 when you have heads off of motor, tighten plugs in, and see how far the threads protrude into cylinder Interesting. Although I had convinced myself (perhaps incorrectly) that carbon could not be the culprit, I'll check this out when get around to dis-assembly. Thanks all for your comments. | ||
| Sagehawk |
To add to post, I have seen some brand of plugs that the threads did not go to the plugs end. About 1/8 inch from end, the diameter would be slightly smaller than the minor diameter of the thread. Another solution but you'll have to search thru plug brands to find if any are still that way. Bout 6 or 8 years ago with that exercise. | ||
| Teeps |
Hoover_uly, Ask and you shall receive: http://www.brokentap.com/services.html | ||
| Ramman4x4 |
Indexing the plug sounds like a good idea, but it depends on whether the cause for the stuck plug is actually carbon deposits or galvanic corrosion or something else... Maybe the best course of action is to perform a plug inspection every oil change if for no other reason than to exercise the threads and prevent carbon or corrosion build up... | ||
| Zac4mac |
For the last 20-30 years, I've been putting Anti-Seize on my spark plugs. reduce torque by 1.5-2X from FSM(dry torque vs. wet torque) There and the exhaust studs ALWAYS. If you're racing, you'll want to "aim" the plug so the gap faces the center of the combustion chamber. Do that with crush washers on the spark-plug before you put the head on the cylinder. Full porting/polishing and a squish-band try to get the most out of a fuel-air explosion. The more energy released(At the right time) the more power to the rear tire. That requires a max in fuel charging the chamber and a small, concentrated flame front. No waste is too small to neutralize. Effin Rocket Science this hot-rod stuff. Z |
