Changed my plugs at the weekend and on inspecting the old ones, the tips were pure dry but on two of the plugs the threaded part had traces of what looked like a shiny grime substance, if that makes sense. It could just be seen on the first 4 to 5 threads. Does this mean anything? There was a slight miss before I canged them.
Cheers.

 

link

 

Cheers mate, excellent link.

 

Thanks a Mill.