Read my spark plug?

my first guess would be too rich with some carbon being blown away to reveal white from previous setting - you might clean it & try again or try a new plug

Too rich... the powdery carbon gets blown off by the spark so it won't stay on the electrode tip...

Too rich.

You need a fresh plug. While that one still works, and may eventually clear more of that carbon - it will make seeing small changes much harder.

Install a new plug & ride it a few minutes to warm up. make a WOT pull then pull the clutch in & kill the engine. When it cools down pull the plug & check it.

It can take hundreds of miles to clear out carbon on an insulator like the plug in your picture. Once you get what you want from the new plug, put that blackened one back in & ride the heck out of it.

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Fully agreed... anytime you get an over rich read, the only way to get an accurate read the next time is with a new plug. I use the Autolite #275 plugs for tuning since they work good but they're also inexpensive at less than $2 per plug when bought in the 4 pack