Help! Spark plugs!
I decided to change out my spark plugs today, and everything was going smooth until I got to the last one. It took me about 10 minutes to finally get it out. And when I pulled it out, I noticed some kind of metallic compound that was at the end of the threads (look at attached pic). Anyone know what it is and why it was so hard to get out? It also left alot of metal shaving behind in the cylinder (pic).