jaka; setting the low speed needle richer makes the problem worse. The rough sound and amount of smoke also indicate that it is running too rich in the midrange. The more I lean the low speed needle, the better it runs in the midrange. When leaning the low speed needle, I get to a point where the mixture at idle is so lean that it won't pick up rpm when I hit the throttle, but the midrange is still too rich. It seems impossible to get both the idle mixture and the half-throttle mixture correct at the same time. All suggestions are welcome.