Do you mean the pilot airscrew? That only affects the running at tickover.
About the only useful reading you can get from the plug is mixture at WOT on the main jet - there's too much noise everywhere else. You can clean the plug and do a proper wide open plug chop to see what the combustion is like there and if good, a little soot from sitting around idling is no big deal. Add another quarter / half turn out on the pilot airscrew and see if the idle rises.
Mostly theoretical as I’m just having fun with a pair of old plugs until the new ones arrive.
Will the soot burn off in a few minutes of riding or will it fuse into the plug marking it permanently?
Do you mean the pilot airscrew? That only affects the running at tickover.
About the only useful reading you can get from the plug is mixture at WOT on the main jet - there's too much noise everywhere else. You can clean the plug and do a proper wide open plug chop to see what the combustion is like there and if good, a little soot from sitting around idling is no big deal. Add another quarter / half turn out on the pilot airscrew and see if the idle rises.