with only 4 digits and a letter, it was made prior to 2004. Tecumseh didn't start dating engines this way until about 1965. with the first number of the last set being "7" it was made in '67, '77, '87 or '97 and on the 288th day of the year, that's just going by their numbering system. They may not have made your particular engine during parts of this period. there are ways of generalizing what decade it was made by things like recoil type, plastic or steel tank, things of that nature.