I hate to start another thread on plug reading but I don't remember seeing this topick. With pump gas I know you will get a carbon ring around the collar and the threads. But will the race fuels also leave carbon on the collar and the threads? I'm trying unical oxy.100 oct.. I'm going to start at the stock base point 1.5 turns, 42 pilot, 162main. and work up or down with the jetting. And I have already done the B.K. mod on my YZ 426. Thanks for your help with another jetting topick.