CONTROLLING TWO-STROKE ENGINE EMISSIONS

With the constant rich operation of two-stroke engines, common design criteria for three-way catalysts fail.

The increasing popularity of vehicles powered by two-stroke engines for cheap and convenient transportation in developing nations of Southeast Asia creates a characteristic environmental problem. Compared to passenger cars with four-stroke engines, carbon monoxide (CO) emissions of two-stroke engines are up to 20% higher, and hydrocarbon (HC) emissions 65% higher have been seen.

In the European Union, governments and environmental groups are concerned about the emissions from two-stroke scooters and motorbikes. New exhaust emissions limits are in effect there and in Japan, Taiwan, and Thailand, with India following in 2000.