The Longuemare, a popular French carburetor, is shown at Fig. 132, while two representative English types are outlined at Fig. 133. The feature of the Longuemare carburetor is the design of the spray pipe which includes an ingenious method of regulating the quantity of fuel spray by a conical plug provided with a number of passages so the fuel is atomized in a number of fine streams instead of one large stream as is the case when a spray nozzle having but a single central opening is used. The small streams are more quickly vaporized and are more easily absorbed by the entering air than the one large stream would be. The amount of gasoline is varied by changing the depth or number of the passages cut on the face of the tapered plug. If the mixture is too rich, one or more of the grooves may be filled in with solder, whereas if it is not sufficiently rich, the grooves provided may be made deeper and thus allow more liquid to flow into the mixture. The form shown is provided with a heating jacket and when used, in connection with an air-cooled motor, a portion of the exhaust gas is usually deflected through this chamber to furnish heat. It is not customary to provide these heating chambers on motorcycle carburetors.
Motorcycles Sidecars and Cyclecars, 1914, by Victor Page
