Stens 615-839 Carburetor Kit Replaces: Zama rib-36 Fits models: Zama: c3m-s12, a-b; c3m-s20, c3m-s21, c3m-s22, c3m-s23, c3m-s24, c3m-s5, d-g Carburetors Ethanol: not compatible with greater than 10% ethanol fuel