I can’t get my buck 650 to idle well. I replaced the fuel pump thinking its sucking fuel through the vaccum line. I have also cleaned the carburetor thoroughly. However, when I remove the vaccum line from the fuel pump and let it suck more air through the opening, it idles just fine. Seem like its running rich at idle? I have tried the idle screw with no luck as well. What would I be trying? Thanks!