The serial number does not translate into a build year for the SB45. Two things will help, however: pictures of the mower, so our SB guru can tell which running changes it does and doesn't have; and if it has a Briggs and Stratton engine, the long series of numbers stamped onto the side of the cooling air cowl. The numbers on the engine will give us the day, month and year it was built, and more likely than not the mower was built just a few months later, if it is the original engine.
