just wondering. ihave heard do to running the carb air fuel mix on the lean side it can burn out pistons. my plugs are the light brown color .they were dark and burnt looking before i leaned out the carb.the low speed needle valve was turned in 5\8 of a turn then i slowly adj till i got hi rpm. it seems to run real well no matter how much or little i adjust in or out.with the needle a1\4 turn out seems to be the spot she purrrs. just thinking it may be to lean but plugs show tan not white. any clues.