+1 what Biknut said about plugs...
Way back when I really wanted to run Champion plugs on my dirtbikes, I learned NGK was far superior.
...seems to me that the outer ring of the plug, (the threaded part?), being tan in color, and the center electrode being black, kinda wet, is kinda backwards what you might want to see. It's kind of odd... It would lead one to believe you have too cold a plug, but the cylinder head itself is running hot.
Although, with E-85 fuel, I have been told ALL plugs in an engine should be more to the black side than tan because of how the alcohol burns???
I am not an expert on reading plugs.
Good luck
rc