Development of a Dual Fueled (Gasoline or Propane) Air Cooled, Spark Ignited Utility Engine

A Kohler 725cc air-cooled engine originally designed to operate on gasoline has been modified to run on either gasoline or propane (LPG and still meet current small engine emissions standards. The fuel system being discussed allows the end user, by means of a switch to operate the engine on either propane or gasoline. The paper will discuss a pre-emission dual fuel system and the changes required to meet emission standards and improve performance.