Sorry, mine is a Mighty Demon 750 - not a speed Demon. Re: the 1/2 turn out on the mixture screws. When I talked to the tech guy at BG, he said to go 3 sizes smaller on the idle feed restrictors - from .036 to .033". When I opened mine up, I found the idle feed restrictors were already at .033. ( new carb out of the box - per their literature - is .036??? ) After the factory "quality control" bells & whistles quit ringing in my head, I checked to see if all else ( jets, air bleeds, PV, etc ) was per the carb literature and all else was as stated. Although my cam duration falls well with in what is suggested for this carb, I have to run it with the "idle-Eze" air bleed wide open and the butterflys open a goodly amount ( boarder line in to the transition slots )to get enough air @ idle.