Abstract: A retaining ring is provided for use in conjunction with a carburetor assembly having a flow passage therethrough for conducting a fuel-air mixture into a combustion chamber, the carburetor assembly comprising an air flow modifier and a fuel injector receiving element adjacent thereto. The retaining ring comprises a collar configured to engage the fuel injector receiving element so as to maintain its position adjacent the air flow modifier, and a retaining portion coupled to the collar and configured to engage the air flow modifier to secure the airflow modifier to the combustion chamber. The retaining portion cooperates with the collar to form an aperture through the retaining ring for receiving the carburetor assembly.