(1) The EPA myth: The EPA did not put the two-stroke out of business (if it did how do you account for the 2012 Yamaha YZ125, YZ250, KTM 125SX, KTM 150SX, KTM 250SX, KTM 300XC, Husqvarna TC150, TX250, TX300, TM 144MX and TM 300MX offroad machines or all the small labour engines such as outboards and chainsaws, also all the small vehicles china etc use?).
(2) Four-stroke power: Four-strokes are not more powerful than two-strokes. Their horsepower and torque come from a common parlor trick called “cubic centimeters.” Four-stroke are only competitive with two-strokes because they are larger. Four-stroke engines are allowed to be as much as 100 percent larger than two-strokes.
(3) Four-strokes are loud. It isn’t just the decibels, it is how far the nasty little sound waves carry. A two-stroke is raspy, but it’s off as much as its on and it sound waves peter out in a hundred yards.
(4 ) Manufacturer's scheme: The motorcycle manufacturers did not manipulate the market into buying four-strokes, but they embraced it because the promise of selling more bikes was hard to resist. The essence of marketing is newness...which is why people get new cell phones every six months...even though the old one still makes phone calls. It should come as no surprise that corporate monoliths the size of Yamaha, Honda, Suzuki and Kawasaki don’t truly care what they sell as long as they are selling something (garden tractors, oil tankers, automobiles, pianos, airplane wings).
(5) Four-strokes are cheaper to produce: Four-strokes are not cheaper to produce than two-strokes. Just the opposite. It costs more to produce a four-stroke engine than a two-stroke engine—a lot more (and eventually they have to charge some rube for the extra parts). The reason that they didn’t run the prices up the flag pole earlier on in the "four-stroke era" is because the new four-strokes had to be accessible. Now, with the two-stroke on the ropes, the greater production costs must be passed on to the consumer.
(6) 4 strokes rule racing, The be all and end all is the 4 stroke rules road racing and motocross because of rule changes, it didnt get there on its own the sport was changed to accommodate this engine type.
(7) and finally if you didnt know any better, 2 views for a newbie
Imagine that I told you that a motorcycle manufacturer was working on a revolutionary engine design for 2013 that was lighter, revved quicker, produced ten more horsepower (per quarter liter), had one-tenth the moving parts, was cheap to produce, cost less to maintain and could be rebuilt for a quarter of the price of your four-stroke? Would you be interested?
or
What would you say if I wanted to sell you a bike that weighed more, was 20 percent more expensive, had lots of extra moving parts, couldn’t be repaired without an ohmmeter and made less power per cubic centimeter? Interested in that bike?
I rather doubt that.
I better get saving up, then... 
instead of wasting my $$$ on race bikes.
