Broken spark plug. Tried Everything, need help

I'm working on a 78 KZ650, one of the spark plugs broke when I tried to remove it.





I've tried pretty much everything:

• PB Blaster
• EZ-Out #5
• Heat (MAPP gas)
• Impact Wrench

And it refuses to come out. I need suggestions/help, worse case would be replacing the head, but maybe it can be avoided.

I wouldn't think about replacing the head. Take it to a machinist and see if he can remove it using conventional methods; most likely he will be able to get it out. If he cannot, find a shop that has a Metal Disintegration Machine (MDM) or does Electric Discharge Machining (EDM) and see what they say. Either of those methods may be worth doing although MDM may be your best bet if conventional methods don't work. Ed

Just checked about MDM and that thing is brutal! (I need to have that!!!!!) I'm checking with machine shops in the area to see how much it would cost (A head out of eBay ain't expensive). Anyway, the engine will have to come apart, because it spins partially.

Thank you Ed.

Pull head have to drill it out and install insert not a bad job.

Just found a shop that can do it. If they can't salvage the thread they will put a plug and tap it.

Time to open that engine!

If you can drill/grind the wall of the plug thinner you can try chipping out the remaining threads and save the original threads in the head.