NIMTEK New Carburetor Carb for Tecumseh 631245 631820 631921 632284 520-918 fits H25 H30 H35 Engine NIMTEK Quality Aftermarket Carburetor Fits Parts Model: H25 H30 H35 Engine. Replace Tecumseh 631245 631820 631921 632284 520-918. This carburetor comes with gasket.