The 1 barrel carburetor is the most basic form of the device. Developed in the early days of gasoline engine evolution, the carburetor replaced the vapor-wick as a more efficient way of introducing fuel into more and more powerful engines. Using the venturi effect to draw additional fuel into the airstream, the 1 barrel carburetor became standard fitment on almost all early engines.
Fuel delivery in modern automobiles has gone through amazing developments, and you won't find a 1 barrel carburetor on any new American car today. But they are used around the world in many applications. They are cheap to build, easy to adjust, and simple to operate. The only things that go wrong with them are dirt and worn throttle shafts. The third world, and much of the second, has learned to deal with these problems. The widespread use of such simple and effective devices is one reason that the first world has such difficulty in enforcing the world-wide adoption of environmental regulations.
In automotive tradition, 1 barrel carburetors were used on the smallest engines. Four and six cylinder engines wouldn't see anything more sophisticated until the late seventies. In Europe one would sometimes see the combination of two 1 barrel carburetors on a small engine in an attempt to wring more top-end power from it. 1 barrel carburetors had the advantage of not only being easy to adjust, but of rarely needing adjustment. There isn't much that can go out of adjustment.
Almost all industrial power plants, from push mowers to wood chippers, are equipped with 1 barrel carburetors. Although many power plants are based on automotive engines, they don't use the complicated controls found in cars. Some of them are primitive indeed. Briggs and Stratton used, for years, a carburetor that bolted directly to the fuel tank. The tank served the purpose of a fuel bowl and needed only to be cleaned out occasionally. The simplicity and efficiency of the 1 barrel carburetor is such that most producers of multi-cylinder motorcycles use four carburetors on a four cylinder engine. Although this introduces the additional requirement of synchronization, it provides simple and reliable power without any undue complications.
Buying a 1 barrel carburetor is usually a matter of replacing the existing one with another, identical one. If one is working with a new application, then it is helpful to find out how much power is expected. A carburetor designed for the same output can then be fitted. This is almost always the only thing that is necessary to do. Idle needs to be adjusted, and idle mixture, in the same manner as any other carburetor. Once that is done, one should have a bulletproof package that will outlast the machine it is fitted to. Don't be afraid to use a 1 barrel carburetor instead of a 2 or 4 barrel unit. When the larger carburetors are sitting on the shoulder, or in the shop, the 1 barrel will cruise right by without a hiccup.
