Today when i took my spark plug lead out of the spark plug side, i noticed a strange brown powdery sort of buildup in the cylinder, like where the spark plug lead and spark plug connect, ie it is visible once the lead is removed from the spark plug, but not taking the cylinder out. It comes off easily with a quick wipe. anyone know what this is?

 

"but not taking the cylinder out"

sry i meant not taking the spark plug out.