4 stroke power vs 2 stroke please help

Ok fellow riders I need your help. I have ridden and raced two strokes all my life. I currently own a YZ250. I just bought my 6 year old son his first bike an XR 70. As you know a YZ250 is not much fun to ride with a 6 year old. I am looking at getting a new 4 stoke.

This is were I need help. Does the WR450 make comparable power to a YZ250? Is the WR250 more like a 125? I do not want 125 power but at the same time I do not want much more than two stroke 250 power. I also ride with friends so need something that can work for both situations.

I guess in summary, can someone let me know how the 2 and 4 strokes stack up for power.


I have a YZ250 that I love on the MX track. I have a WR450 I use in the woods. My YZ is much better on the MX track. The WR has that nice 4 stroke power that works really well off road, climbing hills is the biggest + in my opinion. I think the WR250 is a fun bike but you need to ride it up in the revs and to putt around on after your son it may not be the best choice.

Now on the power. The difference between the 2 stroke and 4 is way different. They both have lots of power its different in the way they make it and will take a bit of getting use to for you, but you will adapt pretty quick.

Don't know if any of that answered any of your questions.

I have a YZ250 and a WR426. The 426 is faster in acceleration, but doesnt have the 'flickability' of the light 2 smoke. The beauty of the 4 stroke is that it is just as happy putting around rounding up the cows as it is bouncing off the limiter. Took me a bit of time to get used to the instant throttle response of the 4 stroke, but once you get the feel for it, it wins hands down every time.

My girl rides the 250 and I follow her around on the 426. She probably rides about as fast as your son on his XR :D Go with the 4 stroke, you'll love it :)


Thanks for the info. It sounds like the WR450 is closer to the power of th YZ250 than the WR250. Hard to give up the two strokes but sounds like everyone here loves them.

Sure do, but I love to get back on my old YZ250 aswell. Beause it's older and looks like crap anyway I tend to go harder on it, especially in the turns. Crash.... bend all the busted stuff back into shape and go again :)

It's great to have a spare bike :D The 4 stroke win hands down when you are out for a more relaxed ride.... it's happy at any throttle opening where the 2 smoke just begs you to hold it wide open and flat change it :D


The way I describe the differece is the 4 strokes HOOKUP where at the 2 strokes HIT. That is the way I describe the power differences.

There is more traction and torque in the thumpers than the 2 strokes of the same class. The 2 strokes come into their own when on the pipe. I have ridden both with the kids (250cc stroke and 426). the 426 seems to have more power and hookup, but both worked out fine. Be sure to have a kick stand though with the kids!!!

FYI - the 450 class machines (YZZ, WRF, CRF, etc) are all designed to be 'equals' of the 250 two strokes. The two race in the same class and the 250 four strokes race in the same class as the 125 two strokes. The 450 has much more power than the 250 two strokes, for reference see the Dec '03 Dirt Rider (pg.82) where they tested the 4 big name 4-stroke 450's against 4 big name two stroke 250's and they have dyno comparisons. Amazingly, the most powerful two stroke was still noticably less powerful than the weakest four stroke.

(following numbers from the dyno in Dirt Rider)

The peak HP on the YZ450F was around 48 and stayed there until after 11,000RPM. The YZ250 peak power was around 44hp and died off after 9,000RPM. Yes, the 4 strokes rev higher beleive it or not. Also, the power difference down low was more noticable with the 450 making 37hp at 6,000RPM and the 250 making 30hp. These were all stock bikes with stock exhaust, etc. so I'm not sure if this relationship will remain the same once you mod a bike.

With all this bench racing aside, the two stroke I rode was noticably easier to flick around than my WR but my WR will run right by it in a straight, up a hill, etc.

- Joe

Matt, I made the jump for the same reason froma CR 250 to a WR400. I am a lot faster on the 400 than I was on my 250, as the power is MUCH more usable. Several of my friends still ride their YZ and CRs. They can hang until there is a hill or a long straight, then it is my tail light they see through the dust! Best part is though, that you can put around going 5mph without fouling the plugs and don't have to do the mix routine. Once you get used to the weight, I doubt you would go back.

Thanks everyone. I got the information that I needed. Thanks for the horsepower information. Once again thanks for taking the time to inform a 2 stroke converter


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