Harley CV Carburetor Drain Screw O-Ring - 27157-89 - Drain screw o-ring for Harley CV carburetors. Replacement for 27157-89 o-ring on CV carburetors that use a float bowl drain screw. For use with 1989-2006 Big Twins and XL Sportster models using the Harley CV 40 that have an external float bowl...