td62

Hi all I'm new here I have a dt125mx 1981 it idles perfectly revs clean on the side stand, pulls away fine but then stutters and vibrates on part throttle and cruising along it is the same, if I open the throttle all the way it sorts it's self out and accelerates fine, if I move the needle all the way up it gets worse so I lowered it which is slightly better but not much I have tried everything I can think of to sort the running issues out I have, Rebuilt the engine top and bottom new everything. New Carb just to eliminate the old carb Rebuilt the original mikuni checked the float height, same running issue with both carbs. Idle jets I have tried 22.5(std) 25 27 30 Moved the needle to every position all the way up makes it worse (clip down) Flushed the tank (running e5) New ignition coil New plug Checked oil pump Checked for air leakage Exhaust is clear New air filter Chain and sprocket set Cleaned up the earth points and checked each plug for corrosion New battery Battery charging fine Checked timing is set correctly Can anyone help me please?