not on my ninja, however. it happened on my 1975 goldwing project bike, because i don't think the stupid ass who had the bike before me ever changed the plugs. EVER. so the 28 year old severly corroded plugs just snapped in two of the cylinders. on cylinder #1, the entire electrode came out, along with the hex head, but not the bottom threads. it's almost flush with the block, and the space is way too small for vice grips. i have never ever seen this happen before, and i wish i had a picture to help explain it better. but now on cylinder #3, the electrode just broke off, taking the hex head with it. the bottom of the electrode and threads are stuck in there. the other two plugs came out fine. my neighbor, who is an engineer at the lab, and builds all kinds of old bikes and cars, is going to take a look at it tomorrow. in the meantime, does anybody have any ideas i can try to get those damn plugs outta there? i really don't want to have to scrap this bike.