The Homelite 309375010 Trimmer Carburetor regulates the mixture of fuel and air supplied to the engine of compatible Homelite string trimmers. It meters fuel and combines it with incoming air to provide the combustible mixture needed for engine operation. Proper carburetor function supports starting, idling, and running performance during grass and weed trimming. Replacing a faulty ca... https://www.wholetoolbox.com/homelite-309375010-trimmer-carburetor/309375010.html