I'm in the process of giving my newly acquired 2005 999s a "once over" and noticed that there's a lot of oil on the Vertical cylinder spark plug! It's also a black colour, which seems to indicate either a perished valve stem oil seal or worn piston rings? I'm going to have a look at the Horizontal cylinder spark plug later but fear that it will be the same :-( If this is the case, does anyone know of a good independent specialist in the Midlands area that would be able to fix either (or both) of these issues?
Is the oil on the tip or around the hex drive/porcelain? The black could be a rich mixture, if the oil is "outside" of the combustion chamber, then it's likely the sealing ring on the head cover is leaking. That's pretty common.
Worth checking the head cover seals before you go replacing stem seals. Any oil past them will get burnt. The oil on the threads has most likely coated them as you removed the plug.
I'll have to get someone with the required skills to diagnose and then fix (it's still under warranty, so shouldn't cost me too much).
