Ha, no Super,

it was the spring from the cap - not the spare. I work on my plane in our "four season's" (actually two seasons - spring and fall - usually too hot to work out there in the summer) sunroom. All my "stuff" is upstairs in my "shop" (which is actually a 11 x 11 spare room!).

Yea, I was going to pry the plug cap off with a screwdriver, but thought better of it and pulled it off instead. But that required me to remove the cowl (because the cutout is so close around the cap and wire and I didn't want to mess up the cowl when the cap snapped off the spark plug).

Yea, a dowell. Good idea! I'll use that next time.