How old is my Briggs & Stratton generator?
Serial number age decoder for Briggs & Stratton standby and portable generators: 1 format era, the decode rule in plain English, transcribed tables, and the official lookup.
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 99011556
- Briggs & Stratton generator serial numbers in the 1965 to present format encode the year as digits 1-2 of the engine code (YY; 99 = 1999) and the month as digits 3-4, day as digits 5-6 (source: briggsandstratton.com).
- Example: serial 99011556 decodes to January 1999.
Format eras
- 1965 to present VERIFIED
########digits 1-2 of the engine code (YY; 99 = 1999)
How to read the serial
1965 to present formatVERIFIED
Shape ######## · example 99011556 · confidence high
- Year
- digits 1-2 of the engine code (YY; 99 = 1999)
- Week or month
- month = digits 3-4, day = digits 5-6
- Plant
- last 2 digits = plant and assembly line
Example: serial 99011556 decodes to January 1999.
Where the data plate is on a generator
Standby units: a plate inside the enclosure or on the frame near the controller. Portables: a sticker on the frame or engine housing.
General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.
For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Residential Propane Backup Generators at 12 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.
No online serial lookup was found for Briggs & Stratton in our research. The manufacturer's customer service line, the installer's invoice, or a printed date on the plate are the remaining authorities.
What we could not confirm
- No official online lookup URL was verified for Briggs & Stratton.
- OFFICIAL: engine CODE number (stamped on the engine, distinct from Model and Type) = YY MM DD + plant/line digits, since 1965. Applies to the engine on B&S-powered generators; the generator's own serial is separate. Pre-1965: B&S antique dating chart. No lookup tool.