Okay to me it sounds like you have your low speed needle set wrong, start up your engine let it run at the lowest idle you can reliabley achieve for about a minute then try and advance it quickly if it just cuts out you are running lean so you need to richen it up a bit and if it stutters and kicks out a bit of smoke as it picks up you are too rich so lean it out a bit by turning the needle clockwise hope this helps Lee.