Briggs & Stratton engines carry a numerical code that identifies the model, type, date of manufacture and assembly line where each unit was produced. Small engine collectors and repair services use these codes to quickly identify the mechanical features of the engine. The code is stamped directly into the metal of a Briggs & Stratton engine. Collectors of antique engines often jump past the model and type numbers to read the date code first.
Wipe any grease and grime away from the code stamp with a cloth or moist towelette. Use a magnifying glass to see the numbers clearly.
Write down the first two numerals in the third set of numbers in the stamped code. These will range from 01 through 12 and correspond with the month of the year. January is represented by 01, February by 02, and the sequence continues through 12, which represents December.
Copy the third and fourth numerals in the last section of the code. These numbers range from 01 through 31 and correspond with the day of the month.
Note the fifth and sixth numerals of the last part of the code. These digits represent the year the engine was manufactured. For example, if the numbers are a "5" followed by an "8", the year of manufacture was 1958.
Ignore the remaining numbers in the code. They represent the assembly and plant where the engine was made and have no relevance in dating a Briggs & Stratton engine.