I have found that adjustment is most successful with the carburetor off of the engine. I start by using a hack saw to put a slot in the mixture adjusting shaft (to avoid using pliers on the delicate splines on the shaft). Remove the bell crank to cut the slot, even better remove the shaft assembly to to do so. Reinstall the shaft. slide the bell crank over the shaft of a screw driver that fits the slot you cut. Using the screw driver to rotate the shaft you will feel the metering pin meet (and lift) the dashpot. This is a matter of "feel". Once you are confident that the pin is just meeting the dashpot, back the shaft off so it just clears the dashpot. slide the bell crank onto the adjusting shaft such that the stop meets the end of the stop screw on the bottom cover. Tighten the clamp screw on the bell crank. The idle adjustment on the throttle shaft is the only other adjustment.