PURPOSE: To accomplish atomization of slow-speed fuel by installing a nozzle body in the slow port chamber of the carburetor and jetting out fuel mixture into the chamber through small holes provided to the nozzle body.

CONSTITUTION: A slow-speed fuel passage 3 is connected to a slow port 5, an opening located near a throttle valve 2, and to an idle port 6, and supplies slow- speed fuel. Between the passage 3 and the slow port 5 a slow port chamber 4 is composed in which a nozzle body 7 is push-fitted. The nozzle body 7 is made hollow and provided with a large hole 11 at its rear end and small holes 10 at its front end. The fuel mixture coming through the passae 3, first enters into the hollow space and then jets out from nozzles 10.