A good idea to determine the source of the engine sputtering and cutting out so you know where you stand. I would probably look first at the carburetor as the idle circuit is apparently okay but that doesn't mean much when operating at higher engine speeds and loads. Ignition is also a possability. Neither the carburetor or the ignition would signifcantly affect the smoking, look at the spark plugs to see if one shows more signs of oil injestion than the others.
