Two Stroke Superiority...in real life

[ddmx]

Here is why the modern day two stroke is lightyears ahead of the modern day four stroke.

Half the displacement, same amount of power
Half the amount of moving parts
Less friction + less moving parts = better performance late in the moto
On average 15 pounds lighter than it's counterpart
100 times easier to work on
$150 dollar all new topend as compared to around $500
Turns better, handles better in general
Less maintainence
top end rebuild in 20 minutes as compared to 2 hours

Finally, the age of motocross started on heavy fourstrokes. Then one day this far superior two stroke bike came along and for the most part all four stroke production ceased. The EPA gets a bug up their butt and then kills the two stroke for this far less superior four stroke. I don't get it.

[FactoryBR21]

Hell yes ! I like 4strokes but 2strokes are always 2strokes too bad everyone are stoping to make 2strokes....

[DankeKTM21]

ktm still making 2 stroke and performing they, not changing just the plastics

[yzmxer608]

Yamaha still makes them too. I think they make minor changes but nothing big, their 125 is close to perfection. That bike won so many 125 shootouts for so many years....

[JETZcorp]

It's not fair to blame the rise of 4-jokes on the EPA. Some of the major bike marques had a vested interest in down-playing the 2-stroke. For example, Honda had very few if any patents on two-stroke technology, and thus were in the uncomfortable position of not controlling development in the industry. Yamaha was in bad shape after not winning any open-class titles in a long time. With the combination of environmental restrictions, 2:1 displacement rules, and political lobbying from some very influential corporations, the stage was set.

Now, however, we're starting to see a trend toward evening up the 2:1 garbage, and the outboard motor producers have developed technology that make 2-strokes as good or better than a 4-stroke, environmentally. Their noise also carries over less distance thanks to its higher note and smaller displacement, so landowners and neighbors are more likely to welcome motocross venues into their area if 2-strokes are the prevalent technology. Add the performance and maintenance benefits DDMX mentioned, and we should hopefully see a comeback. Also, note that very little development has been made on 2-stroke motors since the '90s, and yet the advantages mentioned still exist against brand-new development.

I think a good first-step would be to bring the 500cc 2-stroke back into the AMA and/or FIM. If the open-class beasts go back on sale, people will start to realize what a real powerband feels like. Failing that, direct-injection should find its way onto a bike. This would allow efficient power throughout the RPM range, not just where the expansion chamber is tuned for. It would also mean the virtual elimination of two-stroke oil being burned in the gas, and the raw fuel being blown out the exhaust port.

http://www.youtube.com/watch?v=viWhxvo6DLk
http://www.youtube.com/watch?v=_-7I00cZ ... re=related

[Phathry25]

1/2 displacement equal power isn't true, it's also no a superior feature, it's simple physics.

[JETZcorp]

Right, just in the same way jets aren't superior to horse-drawn carriages, they just rely on physics.

Everything is physics, the point of a design is to utilize those physics better than the other guy. The 2-stroke does that. And you know, if they managed to make a 1-stroke that actually worked, I bet it would kick a 2-stroke's ass in power. It's all about the design.

Also, they do have the same peak power (I'm referring to some Dyno charts JLV posted some time ago... somewhere) although they don't make equal power throughout the RPM range. That said, if you think you need big heavy power at 3000rpm then you probably shouldn't be racing. When you race a 2-stroke, you ride the hell out of it and keep it right in that range where its power does match the 4-stroke.

[ddmx]

hmm...mixed reviews, just what I was going for.

[iceman967]

I agree with bringing the two strokes back. I am riding a 2002 Honda CR 125. I have owned this bike since it came off the showroom floor. Even after racing a 4-stroke for 2 years, I have always had more fun tapping out the 125. Just think; 6-7 years ago watching the pro races, the sound of a piss wound 2-stroke with the mixed smell of race gas and clutch, beat any other smell known to man. I am selling my 4-stroke just because I cannot afford to keep it running if it broke down. With the economy the USA has right now, I would not doubt seeing a comeback of 2-strokes just because they are lighter, more agile, easier to maintain, and so much cheaper to fix compared to the thumpers.

[Voutare]

The only reasons I ride a two stroke right now are for economical/fun factors.


I work at McDonalds making $8 dollars an hour, so I'm quite a bit limited on my finances, which is why I ride a two stroke. They are just cheaper. Compared to a four stroke, it's easier to maintain, and it's easier to have fun.

However, if I were going to dedicate myself to racing, I would easily take the four stroke. Why?

1. Because of the 2:1 displacement rule. Hell, why not take advantage over it?
2. Because I'm a lazy SOB. Two strokes give me too much of a workout.
3. Because they are easy to ride.



It's not about what is better, it's what it is used for. And I just love the sound of a four stoke. I've heard two strokes too much over my lifetime.

[JETZcorp]

If you've ever eaten a taco, you'd have heard the sound of a 4-stroke too much, as well.

[Phathry25]

For me the 450 is harder to hold on to, and that makes me more tired. On the 2 strokes I can just flow.

Jetz, show me a dyno chart from a 250 2t that has 63hp, I have one from my 450, that's less than 2:1 displacement...

[Voutare]

For me the 450 is harder to hold on to, and that makes me more tired. On the 2 strokes I can just flow.

Jetz, show me a dyno chart from a 250 2t that has 63hp, I have one from my 450, that's less than 2:1 displacement...

Well a 450 may be different. I have never really rode a 250 2t or a 450. Comparing a 125 to a 250f though, I definitely think a 250f is easier to ride.

[rgaede]

Welcome back to the two stroke fold ddmx! And phathry, we don't have access to the factory race bike dyno numbers. one year, forget the year though, ktm did make a stock 250 2t that made 52 horsepower, and you could add two to that by purchasing the mcgrath pipe from pro-circuit. This would put you around 54 without porting/higher compression/or race gas.

[russ190]

I race both my 125 and my 250F. Love both for different reasons. But maintaining a 4-stroke is NOT THAT HARD. Just freaking change the oil more than once and a awhile. You do that every time you put gas into the 2-stroke. Yes parts are cheaper and its easier to maintain the 2-stroke, but hell at least its not a car your working on for 8 hours to race for 15 min right?
I went last season on one top end on both bikes, now im not the best rider but my A buddies only do it once maybe 2 times a year as well. Lack of maintaining the bike is what ruins it. For example, a guy recently was told by a mechanic to do the top end on his 250F, he decided to ignore said guy and go another 7 months on the top-end that was worn. Now he has to spend about 2k to fix it on parts alone if he can do it. But he ignored the orginal problem so its his fault. Its no longer just the top-end thats wrong obviously. It may take more time to work on the 4 strokes but they each are fun. Riding is riding. Ride what makes you feel fast