Image: one page of 1939 brochure from http://www.usmotorbikemuseum.com/whizzer_3.htm .
“Breene-Taylor Engineering, a Los Angeles-based manufacturer of airplane parts, announced the availability of the Whizzer Model “D” Bicycle Motor. This kit sold for $54.95 and included an air-cooled, four-cycle engine that was capable of producing 1.375 horsepower as well as a 2/3 gallon fuel tank. Approximately 1000 Model “D” motors were made and sold.”
At the beginning, the Whizzer was only a motor to be added to the customer’s bicycle.
Excerpt from http://www.whizzermotorbike.com/History.html .