With the invention of more efficient four stroke motorcycles today, two strokes are being threatened. Two stroke motorcycles produce power and release the exhaust all in one revolution of the crankshaft. This gives the user more bang for their buck. Two strokes are have an extremely superb power to size ratio and were the industry standard, until 1997. In 1997, the Environmental Protection Agency (EPA) decided that it was their time to take action against the two stroke. The EPA argued that the two strokes are inefficient and pollute too much into the atmosphere. While this is somewhat true, they are not nearly as bad as the EPA makes them out to be. The exhaust that is seen is in fact the oil being burnt off because two strokes rely on the lubrication of the engine through the fuel. The actual emissions are close, it's just that the smoke is being added to the exhaust, and this is seen. The EPA also argues that two strokes are too loud. Nobody started to complain about noise until 1997. Which was when four stroke technology boomed. Four strokes are the alternative to a two stroke. Four strokes make the combustion process 4 steps instead of two. First, fuel is drawn in, just like a two stroke. As the piston moves up, it compresses the fuel. At this point, the engines show their differences. The four stroke will combust the mixture, making the power stroke, then the piston will come back up, making the gases travel outward. The two stroke just pushes the gases out and comes back for more. The four stroke has two rotations of the crank for every 1 power stoke. Four strokes have a sump oil system, which will not get in the cylinder, thus, not burning (the main reason why two strokes are claimed "inefficient"). While this is a lot of information, it's important to understand theses things to see the economic impact that this will ban will have.
Banning two strokes is the wrong choice on the battle against pollution.