Hobbit is right in there! NORMAL unless HEAVY FLAKEY stuff
BUT also if you suspect a rich mixture, CHECK BOTH sparkplugs,,,,, IF they are sooty BLACK, TOO RICH..
I also would suggest to put a LITTLE anti seize on the plug thread when putting the NEW plugs in....
MIGHT just as well go with NEW while old are out. I ONLY recommend the $$cheap STOCK HD plug and NOT the pricey ones!