Previously oil had to be mixed with gasoline. Today, most two-stroke engines are equipped with separate lubrication when the oil tank from a separate special miniature pumped into the flow of the combustible mixture. Pump performance depends on the degree of rotation of the handle of gas: the greater the power, the oil is fed more. Such a system reduces oil consumption. But it Yet in the end it turns into a combustion chamber and, as it burns down there, though not completely. This explains the blue smoke from the silencer push-pull technology. This smoke than a whole set of harmful substances present and nesgo-revshee fuel flown away into the pipe after gas and oil spray. From the perspective of environmentalists is a huge disadvantage.
In two-stroke engines, there are other drawbacks as well associated with the principle of operation. Oil, diluted gasoline lubricates poorly rubbing parts, and strokes in "dvuhtaktnikov" twice, so their share is much lower. Reduces the durability of parts and constant flushing crankcase air, which there is always a hard sand, "skip" through the air filter. Of unburned oil on the piston in the combustion chamber and the muffler is rapidly formed carbon deposits, piston rings, "occur" in the grooves, because of what the engine power falls. The slightest violation of the oil supply, particularly in hot and heavy until goad conditions may be oil starvation, pregnant with a bully and a piston engine failure.
Two-stroke engine with more naughty run, it can, for example, "throw" a mixture of candle, he is more prone to overheating (no forced cooling). The dramatic opening of the piston of the exit window leads to an unpleasant cod at work, despite the presence of muffler. Finally, moped or motorcycle with a "dvuhtaktnikom" worse than slow the engine. All this taken together led to almost stop the production in developed countries, two-stroke motorcycle engines of more than 125 cm3. The exception is sports motors, where high power density, co-toruyu provides a two-stroke cycle, is a priority. Exploiting the four-stroke engine, one must constantly monitor the level of oil in crankcase, and in time to replenish it in time to replace oil. It is also necessary to monitor and regulate the gaps in the actuator valves. The owner of a scooter with a two-stroke engine should control the availability of oil in the tank, periodically clean the combustion chamber, exhaust pipe and a candle from scale, to monitor the thermal state of the motor.