Carbureted

Carbureted refers to engines or fuel systems that rely on a carburetor to mix air and fuel before combustion. Carburetors were the standard method for metering gasoline in automotive and small engines for much of the 20th century, before electronic fuel injection became prevalent in the late 1980s and 1990s.

Operation involves air entering the intake and passing through a venturi, where the moving air creates a low pressure that draws fuel from a float-operated chamber through jets. The throttle plate regulates air flow and the amount of fuel via metering passages. Idle, cruise, and enrichment circuits handle different operating ranges, and a choke or automatic cold-start mechanism enriches the mixture during cold starts. Some carburetors use diaphragms or vacuum actuators to control fuel metering.

Maintenance and limitations include the need for periodic adjustments and cleaning; floats, gaskets, and jets can wear or clog, affecting mixture and performance. Carburetors are sensitive to altitude, temperature, and fuel quality, and can suffer from icing in certain conditions. Compared with modern fuel-injected systems, carburetors typically offer less precise fuel metering, higher emissions, and sometimes poorer cold-start performance, but they are simpler and cheaper to repair.

Applications include engines in lawn and garden equipment, some motorcycles, classic cars, and certain light aircraft. In many regions new vehicles use fuel injection due to efficiency and emissions standards, but carbureted engines remain in use where simplicity and cost are advantageous. The term carbureted highlights the mechanism rather than performance.