Rotax Sparkplugs

I have heard of this from a couple of owners, but I have never personally seen one unless it was dropped or someone tweaked it when torquing it in or removing it.

Torleif,

Were there any spark plugs where a chunk of the porcelain was missing?  If so, it might be worth looking in those cylinders with a bore scope to make sure there is no damage.  I’ve not seen it, but it would seem that porcelain is hard enough to scratch the cylinder wall.