i've got a brand new plug in it, cleaned the carburetor and everything. it starts first kick every time, but when i take off it wont wind out, it gets to a certain rpm and starts missing and sputtering. when i let off the gas it wont idle, it bogs and dies. ive adjusted the carburetor every way there is to adjust it, even the idle screw but it doesn't help. what could be the cause of this?