Looks like you had.an air/fuel leak between the crank case and cooling head.
That's why there's a burn mark on the piston and a collection of muck on the lower portion of the crank case.
Either two of the screws attaching the cooling head to the crankcase were loose or the cooling head itself may be warped.
Once you address that issue your engine should be easier to tune.
Well I checked the tightness of the cooling head before I run it each time and it's never loose. And it's a new motor I'm on the 20th tank. I broke it in to what they said. Running it pretty conservative too not really going high temperatures, they're around 250. And the tuning isn't to hard on it. Can I put another little brass gasket type thing on it and fix it? Or should I use something to just seal it?