Tom,

Yep, a white plug is lean, it sounds as though there is dirt in the carb. Take of the plate on the same side of the carb as the fuel inlet. Right where the fuel inlet comes in is a very fine mesh screen. My bet is that screen has some dirt in it.

Clean the screen and set the needles to factory specs and retune

YOu could have an air leak as well but I'm betting on dirt in the carb

BTW...I never run a gas engine over 200 degrees and love to see 180 to 190. At 230 degrees it will not take long to toast the cylinder and ring and by long I mean a tank or two