A-B1396568-AI VALVE-HIGH SPEEDOne New Aftermarket Replacement High Speed Needle Valve Fits Briggs & Fits Stratton Small Engines This aftermarket replacement high speed needle valve (also called a high speed mixture adjustment screw or main jet adjustment needle) Fits Briggs & Fits Stratton single piece float type carburetors. The high speed valve threads into and retains the float bowl, controlling the fuel air mixture at higher engine speeds. A worn or damaged high speed valve