Is it smoking and dies slowly when it quits or is there no smoke and it is quitting instantly. Where is the low speed needle in relation to the end of the throttle barrel? My guess is that it is too rich, if so set the high speed needle to peak rpm and leave it there temporarily then lower the throttle to lowest speed possible the way it is running now. Now procede to turn the low speed needle cw 1/8 turn at a time rechecking the top end every other time, at some point one of those 1/8 turns is going make a big difference all at once. Now you're close, just keep at it until you get the idle and transition you want. Be willing to sacrifice a little on the lowest idle speed to get a better transition. Don't listen to anybody who says it won't idle right until 18 gallons of fuel has been run through it. You can have a fantastic idle about 25 minutes after the break in is begun. when satisfied, reset the top end a couple of hundred rpm rich.