Exhaust gas recirculation means

In an internal combustion engine having a carburetor including, a choke section constituting an air intake portion of said carburetor, a venturi section connected downstream of the choke section and provided with a venturi, a fuel introduction system connected to said venturi section for introduction of fuel into air passing through said venturi section, and a throttle section connected downstream of the venturi section and provided with a throttle valve, a slow port and idle port and communicating with an inlet manifold leading to a combustion chamber of said engine, the slow port and the idle port being positioned respectively upstream and downstream of the throttle valve when the throttle valve is in the fully closed position, and

• exhaust pipe means for removal of exhaust gas from said engine;
• exhaust gas recirculation means comprising:
• port means which opens to an interior portion of said carburetor which is intermediate said venturi and said throttle valve;
• an exhaust recirculation line which has an inlet end portion connected to said exhaust pipe means, and a delivery end portion communicating with said port means for delivering exhaust gas through said port means into said carburetor, and flow control means in said exhaust recirculation line adjustable to control the flow of exhaust gas;
• and
• a supplementary air duct in said carburetor, and which has an inlet end opening upstream of said venturi, and a delivery end portion communicating with said port means for delivering air through said port means into said carburetor.