2-stroke vs. 4-stroke dirt bikes?

I would like to know the maintnance, reliability, and performance differences between 2 stroke and 4 stroke MX bikes.

Outside of the 85cc and under classes almost no one is on a 2 stroke and there is a reason for that, they want to win. Don't get me wrong, I still love 2 strokes but because of the way the AMA has set the rules the 2 strokes are just at a big disadvantage. I really don't think the rules are fair, and I believe the AMA is helping the industry push the 2 stroke out of the sport and eventually out of production. Running a 250 4 stroke against a 125 2 stroke is just not fair. After many complaints the AMA changed the 2 stroke displacement limit to 144, but by the time you buy a new 125 and have it built up to a 144 it is more expensive than a 250F. The rules being what they are, here are the facts. The 2 stroke will lose the drag race to the first turn every time, and because the 4 stroke power is so much smoother your corner speed is much faster because you stay hooked up rather spinning your rear wheel exiting the turn. Also I get far less arm pump because the 4 stroke has so much torque that I'm not constantly clutching the bike. As far as maintenance goes, the 4 stroke maintenance has been blown way out of proportion. It may cost me twice as much to rebuild my 4 stroke but I'll do it half as often as a 125 2 stroke. The only extra maintenance on a 4 stroke is having the valves checked and adjusted a couple times a year. A small price to pay in my opinion. I have raced 2 strokes my entire career until last year. Once I threw a leg over a 4 stroke I knew I'd never ride a 2 stroke again. One side note, most A class woods riders do like the 2 stroke, but for motocross the 4 stroke is far superior. The factory riders have to ride what the team tells them to, but privateers like myself ride what we want. Just go to a local MX race and see how few, if any, 2 strokes are out there.

2 stroke is better for high prefomance and you got the power band which is bad ***, the four stroke is low maintenance but your not gonna get as much out of it
Modern (2000 and later) four stroke MX'ers are more expensive to maintain than their two stroke counterparts.

They have more moving parts, the parts are more expensive to replace, and they have more frequent required maintenance than two strokes.

Currently, on the professional level, the four stroke is the weapon of choice.

However, for local B, C or Novice riders, I really recommend a two stroke. The power difference isn't going to be a factor - at this level, it's all rider skill.

Modern two stroke and four stroke MX'ers have similar power delivery, with two strokes being a bit easier to ride, especially when you're tired.

Without getting extremely specific, the peak horsepower of a 125cc two stroke and a 250cc four stroke is about the same (with some two strokes edging out some four strokes), but the four stroke has more torque. So, overall it's got more power.

Same with the 450 four stroke and 250cc two stroke.
I work for a four stroke performance manufacturer.
All around cheaper,lighter faster,more fun,the two stroke.Unfortunately the two stroke is being forced out of circulation by EPA rules.This means that parts will become more difficult to obtain for them at some time down the trail.So, yah 4-stroke,we are stuck with hardly no choice and to go thier way.Great machine ,thier just to heavy.
Old MXER
4 strokes all the way. two strokes in there day were awsome. but 4 strokes have come so far and are now faster and more reliable. I myself am an owner of a 2007 yz 450f and it is the fastest and best bike i have ever owned and i have owned many 2 stroke and 4 stroke bikes. trust me 4 strokes are the way to go!

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