My roadster sounded like it wasn't running on all cylinders. When an 8's running on 7, you can sometimes miss it at idle, but when a 4-banger's on 3, you can't miss it! So I decided to check the spark plugs... took out the first one, "SNAP!" Oops, I blamed that one on myself. Wasn't paying close enough attention, had the socket on crooked or something, right?? Nope.
Next one, snap... next, snap... All for plugs broke when I took them out. That was NOT my fault. Luckily, I had some old Autolites from a previous tune up. I put them in and the miss was gone and just to make sure it wasn't me, I took one back out. NO PROBLEM!
So, here's the carnage. 4 of 4 broken plugs. Never again.