You'll find Tecumseh small engines powering lawn mowers, string trimmers, riding mowers, chain saws, snow blowers and other outdoor tools. Each Tecumseh engine has a date-of-manufacture code included with the model number that shows the day and year the engine was built--though for engines made before 2004, you still need to estimate the decade. The code also contains other information about the manufacture of the engine, such as the factory and production line where it was built.
Look for the engine model number. You may find it stamped on the blower housing or on an engine identification label located on the front or top of the engine or under the engine cover.
Find the date-of-manufacture code, usually found near the abbreviation "D.O.M." or at the end of the engine model number. The code begins with five numbers (or four, if the engine was made before 2004) followed by one or two letters. There may be more numbers after the letters, but the first four or five numbers will tell you when the engine was built.
Use the first one or two numbers to estimate the year of the engine. If there are four numbers, the engine was built before 2004 and the first digit is the last digit of the year. For example, 2 means the engine was built in 1982, 1992 or any year before 2004 that ends in two. You must estimate the decade. If there are five numbers, the engine was built in or after 2004 and the first two digits are the last two digits of the year, for example 05 for 2005.
Use the final three digits to calculate the day of manufacture, since they indicate the day, starting at 001 for January 1 and counting up to the end of the year. Begin adding the number of days in each month, 31 for January, 28 or 29 for February, 31 for March, and so on, until you reach a total just below the three-digit number. The last month you added is the month of manufacture and the remainder is the day of the month. 032 means February 1. 060 means March 1 unless it's a leap year, in which case 060 means February 29.