You have a bad tune. Your running more than likely too lean.
You need to reset the needle back to factory settings. 2.5 to 3 turns out from seet on the high speed needle, flush with the collar on the low speed and a 1mm gap on the idle.
Then you need to tune the Idle needle first, get the endinge warmed up, by starting it and holding your finger on the trigger alittle bit to let more air in the intake, so it will start. get it so it stays idling. Once you get it to stay idleling you want to work on the high speed needle. Make a highspeed pass and see how it runs, lean it out alittle then do it again. What your looking for is the point that the engine starts to cut out or act like it's stalling when you have the throttle WOT(Wide Open Throttle) once you hit that point you want to back the needle out an 1/8th turn and you should be good. Remember that these engines are NOT designed to do WOT constantly, they are designed around the basis that you are on and off the throttle like as if you were driving on a track, so if your doing constant WOT all the time the engine will run hot and cut out eventually no matter how you tune it. Now you want to work on the idle nd it shouldn't need more than a 1/16th to an 1/8th turn in to get it set right. You want it to take off immediatly when you hit the throttle, not a delay of a second or so while it blows out the fuel. Once you get it dialed in it shouldn't be a matter of changing the Highspeed needle from one way or another no more than an 1/8th of a turn to get it tned on any given day. If you're constantly screwing around with the needles then your not tuned properly. Remember this takes practice. I can tune a 6 barrel carb, but it took me awhile to get the hang of it, I kept trying to tune these carbs like you would a car. You want the idle to be set so the car is idle what sems kind of fast, to where the car is wiggling like it wants to take off but it's just not takeing off.