The power system ensures the supply of purified air and fuel to the cylinders. The book talks about the power system of automobile engines, carburetor and diesel engines, fuel and working, as well as lean, enriched and rich mixtures. The publication discusses in detail carburetors, the power system of a carburetor engine , the principle of operation of the simplest carburetor, a diagram of its structure and operation, as well as the main metering system, the idle system, the ecomizer and the accelerator pump. In addition, the book informs about the limiters of the maximum crankshaft speed, fuel tanks, fuel supply to the carburetor, faults in power system of a carburetor engine. Maintenance of the power system of a carburetor engine, the power system of gas and diesel engines, the engine starting system, as well as malfunctions in the power system of diesel engines and its care are separately considered.