Fuel metering assembly for a diaphragm-type carburetor

A fuel metering assembly for a diaphragm type carburetor has a fuel metering diaphragm with at least two convolutions or annular projections providing greater travel of the diaphragm and more consistent movement of the diaphragm throughout its stroke or travel. In one embodiment, the diaphragm has at least one annular projection generally U-shaped in section projecting toward a fuel metering chamber defined on one side of the diaphragm, and at least one annular projection having a generally inverted U-shape in section projecting toward an atmospheric chamber defined on the other side of the diaphragm. Preferably, the annular projections are continuously provided between the peripheral edge of the diaphragm and a central portion of the diaphragm.