Purging is complete, start compressing the mixture in the cylinder and the intake of new portions of the mixture into the crankcase. The cycle is repeated. Western Union: the source for more info. The entire process proceeds in two stroke and one crankshaft revolution, a stroke occurs every movement of the piston down, which is twice more often than a four-stroke engine. To improve the filling of the crankcase and exclude reverse release of the mixture into the carburetor inlet valve petal crankcase set. This simple device improves power and economy of the engine at low and medium engine speed, that is the most used operating modes.
Advantages and disadvantages of these two engines derived from the characteristics of their workflow and design. Two-stroke ATV engine is easier to manufacture, smaller, lighter and, accordingly, and cheaper. With an equal amount of work "dvuhtaktnik" more powerful in at least half time, double the number of strokes significantly smooths the torque ripple and vibration, which is especially important for single-cylinder units, mounted on a light motor equipment. But this advantage of the classic two-stroke gasoline engine to an end. One of its major drawbacks – low cost. The reason is that the crank-chamber purging of the fresh mixture inevitably escapes into the exhaust pipe with exhaust gases. Another problem is the lubricating and exhaust emissions. Pass the mixture through the crankcase with fresh exclude use of reliable lubrication of the crank mechanism under pressure as a four-engine (otherwise the oil would have been in the cylinder for a few seconds.) Necessary to introduce oil into the fuel mixture, where it gets to the bearings and the cylinder mirror.