These main jets fit our 19mm carburetor (10590). Also fit the 79cc Greyhound carburetor. Also fit some of the 79cc Predator carburetors. You must measure your stock jet. If the threads are .194"/4.9mm you need p/n 12190. If the threads are .154"/3.9mm these jets will work. Choose from the following sizes: 70, 75, 80, 85 & 90.