aisan is a Japanese specialist in fuel pumps. Founded in 1938, the company began producing automotive parts and carburetors in 1945. At the end of 1953, it tried its hand at two-wheeled motorized vehicles with a moped, the Spit. A technology supply agreement was signed with Rohmann in Germany, and production and sales of the Spit AS Type bicycle engine began. It was the "ultimate engine" with a variable compression mechanism and a hypergolic pre-mix compression system. But production stopped after just 1 year due to various problems, including those with its starting performance and durability at low temperatures.
The Asian Spit, with a 25 cm3 engine
