could the serval benefit from bigger carbs...yes......do they NEED them to run better then the stock setup.....NO!.....if ur going to rebuild and are debating upgrading....JUST DO IT!. best money youll spend, and when you want to go faster, or ur clutch starts slipping, or u cant shift worth a damn....UPGRADE SOME MORE. thats what im doing, just with a cub. by far the funnest money iv spent on this bike.