These engines really like a much leaner bottom than some other engines, sort of like the OS. That's why we recommend the hot plug to clean out the midrange and just run better on bottom. Tune to scream on the top, and then lean the bottom just this side of lean bogging. One more tick rich and you're good. ..also, yes, the thing will come in lean with an empty tank and a little on the hot side, but that's normal. As long as it runs clean through the middle part of the tank, that's what you want.