31386 Tecumseh Spring. No original manufacturer's packaging is available. Fits Toro: 16268, 17501, 18070, 18171, 18208, 18213, 18215, 18221, 18257, 19173, 19222, 19251, 19271, 19333, 19373, 19472, 20222, 20227, 20571, 20600, 56027 series engines