It's not a matter of 4 strokes being heavier but it does hender them somewhat, it is that it takes two more strokes. 4 strokes are starting to out perform the 2 strokes mainly because of new advances which older 2 strokes have not had a chance to become apart of. If two strokes never stopped being widely used for performance atv's then there would still be the huge difference between them. Personally I think 2 strokes stink and make alot of noise and I would never care to own one but to each his own. They will soon have it narrowed down but still it is impossible to make a 4 stroke to out POWER a 2 stroke of the same cc's, old technology or not.

 

how can you tell a 440ex from the stock 400? Or do you just know this from asking people what they have done to their bike?

Does the 440 kit come with a new jug or is the cylinder just resleeved or bored out?

 

listen to it...

and then WATCH it, you will be able to tell

 

The only reason thumpers can even begin to hang in AMA motocross is that they have double the displacement.

The other day I was riding with a guy with a 2001 Yamaha YZF250 thumper and he was bragging on how fast it was (because he races it in the 125 class). Well, he lined up next to me on my KX250 and I smoked him so bad it looked like his chain must've come off ... and that bike is the highest tech thumper there is (5 titanium valves and all).

We will probably all be riding thumpers someday thanks to the EPA but it WON'T be because they were faster than our old two strokes. More tractable and easier to ride? Probably. Faster? Never.

Also, there is nothing sweeter (in my opinion) than the smell of burnt premix in the morning!

 

You can't be serious!?!? A 250F on nitro and supercharged would last about 5 minutes and to make a 4stroke perform respectfully it will use just as much gas as a properly tuned 2 stroke and the farther you push the 4 stroke the more gas it will use.I have in depth proof of that, I don't feel like typing it all out,but if you challenge it, then i will have to.4strokes will never be superior to 2strokes, but the way people seem to embrace a heavier slower design IE, When will the 440s take over the race track? I'll tell you when, as soon as all the pros die in a plane crash.For the local yocal who isn't dedicated to a racing profession a 440 is an easier alternative, but for an actual pro looking to win, the 250 will always as it does now,dominate.

 

there is so much technology now that they are getting mods that can make 4 strokes beat the 250's 2 strokes that are out now. But now every large engine place is coming out with powervalved topends for honda 250r so they should start to keep up with the super moded 4 strokes there now.

Travis spader is one of the only pros that had a power valve last year. And from what I hear the engine was a big part. With the power valve the 2 strokes can have tons of lowend torque (that will hook up) and still rev out. I think next year there will be lots of 250s yet well i guess i should say 265s.

 

Well, I'm not an expert, but I'm just going by my experience... My stock 400ex is just as fast as my friend's LT250R, and he goes through twice as much gas as I do... same with a race modded 440, it'll keep up with a modded 250R, and get better mileage at the same time. It's just a more efficient engine design; less unused gas goes out the tailpipe, cleaner burning, lasts longer, etc.. The only place it's less efficient is weight, and even that difference can be minimized, depending on how much money you want to spend on lightweight parts.

Maybe saying a 250F could make as much power as a 2-stroke is a bit extreme, but you can't just look at peak numbers, you have to look at overall power, and the four strokes have a MUCH broader power curve, because they don't rely on harmonics and tuned frequencies as much as the 2-strokes do. Also, you can't really compare cube-for-cube anyways, because like was said earlier, a 2-stroke produces power twice as often as a 4-stroke. So, if you want to get the most peak power out of the smallest, lightest package possible, regardless of fuel efficiency, then sure, the 2-stroke wins. But 4-strokes will always be the more fuel-efficient, longer lasting, lower maintenance engines.

 

Quads are getting waaaay too technical for me these days

 

BlahBLahBlah, "broad power curve" "smooth powerband" A 400EX is not as fast as an LT or TRX 250R, it makes less hp and weighs more plain and simple. Save the "broad power" and "smooth power" for the kids and beginners, a 250 is superior for the expierienced.

 

You can't be serious..


So, here is the big $$$ question. Would it be foolish to invest in a 250R race quad now?
How long do you think the 250R's are going to be around? A race modded 400EX is going to cost as much as a mighty fine 250R, and still be heavier, and I don't think it will have as much power.