The laws of physics will always prove the two-stroke as being able to produce faster response than an equal four-stroke motor. Unfortunately, the EPA is more concerned with the air around each of them. The two-stroke will always loose this battle since it relies on combustion of an oil and gas mixture. I hate to use the word "never", however it seems very unlikely anyone can find a way to leave no leftover oil in the exhaust of a two-stroke.

 

i can believe it, Honda is already starting the trend with their Personal WaterCraft, and the 450 4-stroke motocross bike, 2 strokes will be able to stay around as long as the companies can devise a way to make them more efficent and less polutant, look yamaha made a 4 stroke bike, why would they do that? to compete with the 400EX but i think mostly to get the banshee out of the picture in a year or two... just my $.02

 

There only making 4 stroke motocross bike because for the time being they let 250cc 4 strokes race 125cc 2strokes and 400cc 4strokes race against 250cc 2strokes.Now the race fans are saying they only want see 125s racing in the 125 class and 250s racing in the 250 class no matter what type of motor is in it.
We will be growing tomatoes on Mars before we ever make a 125cc 4 stroke that can race a 125cc 2stroke in a MX race.

 

honda hasnt produced the spree in years

 

I think that if the large manufacturers stop production of two strokes the smaller aftermarket companies will step up and build motors. There are just too many people who are unwilling to give up thier two strokes. For many situations they are clearly superior to four strokes. Who would want a four stroke snowmobile?

 

Redline is going to make a 800 v twin four stoke sled, It will suck 2 stroke rule!!!