G'day Speedy and Mf,
The 2 stroke Falcon would be from the late eighties to the nineties,Jetfast / SupaSwift
The Komatsu Zenoah Venture – In May 1987, Briggs & Stratton entered into an agreement with yet another Japanese company, executing a 10-year contract with the Komatsu Zenoah Company of Tachikawa, Japan. Under the terms of the contract, Komatsu would manufacture a 2-cycle, 4 hp (3 kW) engine, in which Briggs & Stratton would purchase and distribute in the United States, Europe, Australia and New Zealand., "This venture was not successful, because the rising price of the yen made the engine too expensive in the U.S etc.
Cheers
Max.