Motorcycle Repair: Broken Spark Plugs /Removal,Repair, quality plug, harley davidson

Question
Hello Jan,Here is general motorcycle problem ,that happens alot I gotta believe,however have NOT SEEN many blogs about it on-line. My good friend rides,and broke off a spark plug,while changing them the other day.The plug broke off on the threaded portion of the plug,the insulator ,as,well as the nut portion,broke away....So , the ONLY PORTION of the plug remaining,is just the threaded portion,in the head,nothing else.               Is there a special tool,or a technique,helping service,repair"tricks" you can share with all of us ,who have had this problem? The plugs are Harley Davidson Brand, I would reccommend to everyone  "NOT"to  use them,this bike had very low miles,and a licenced aircract mechanic removed them from the bike. Use a better quality  plug,more expensive,get the quality,save yourself a huge hassle,people.   Thank You Jan, Oh, and ALWAYS use antisieze when replcing spark plugs.

Answer
I think you will find these plugs are manufactured by someone else and have the HD stamp put on them.  I have never, ever, had this problem, but then I only work with Honda's.  Have stripped a few threads removing plugs that were seized, but never broke one off.  Good luck with the project, I would drill the remaining steel out and then see if you can remove the remaining threads.  Not easy.


Jan