Patent ID: 9027910
Filing Date: 2015-05-12
Classification: F02M

Abstract:
1. A carburetor having an air passage and a fuel metering system for supplying fuel to the air passage and including a diaphragm assembly that moves in response to pressure changes in a fuel metering chamber to actuate a fuel metering valve, the diaphragm assembly comprising: a flexible diaphragm having a fuel side and an opposite reference side and carried by a body of the carburetor at a periphery of the diaphragm with the fuel side at least in part defining the fuel metering chamber and normally in contact with fuel in the fuel metering chamber and in operation supplying fuel to the air passage, the portion of the diaphragm that defines part of the fuel metering chamber defining a chamber projected area of the fuel side of the diaphragm; and a backing plate attached to the reference side of the flexible diaphragm and outside of the fuel metering chamber, the backing plate having an outer perimeter defining a plate projected area, wherein an area ratio of the plate projected area to the fuel metering chamber projected area of the fuel side of the flexible diaphragm is greater than about 0.1.