hi i have an oldish 20 hp twin<br />it wont take full throtal..just dies<br />unless i give half choke<br />so i presume fuel problem<br />there dosent seem 2 be a main jet?<br />how do i check the fuel level?<br />there is a lg screw on the top of carb[mixture ajustment]i think...how do i set this<br />what else should i look for? fuel tank and pipe is new...lead replacment petrol ok?...50/1 oil mix<br />thx for any help guys