why do people think 4 stroke dirtbikes are the future.?

Answer 1

First I hate it, but 4-cycles sip fuel, make gobs of "usable" power, put VERY clean exhaust emissions out, and take strait pump gas. I don't like it but they are the future.

Answer 2

Despite Everything else, the only reason 4 strokes are becoming the future is because their cleaner. 2 strokes are powerful and loud, and environmentalists dont like that. 2 strokes are actually cheaper to maintain then 4 strokes are, because of the titanium parts used in 4 strokes. And even though they make more power, a 4 stroke has to be twice as big to keep up with a relative 2 stroke. But environmentalists are causing the problem, and motorcycle companies listened.

Answer 3

Good question. Considering that a two-stroke of the same cc will generally crank out a bit more power than a 4-stroke of the same cc--particularly on the low end-- performance enthusiasts are kinda bummed. The advantage is largely due to the fact that...well...the engine gets to spark twice as often. It's a less efficient spark, but it happens twice as often.

I'll tell you why I think 4-strokes are the future (at least, in the states). In a word: Regulation. It's not just politically correct...it's required by law that manufacturers selling bikes comply with EPA rules. The fact that 2-strokes are soon going to be required to adhere to more stringent EPA requirements means that manufacturers are leaning away from them, and trying to produce viable 4-stroke alternatives. Why? Mostly because it's cheaper to crank out old 4-stroke technology that will meet the EPA requirements than it is to re-tool their 2-stroke designs. It's entirely possible to make a 2-stroke that meets guidelines. But given the choice of working out a new 2-stroke design without diminishing power vs. 4-stroke...the 4-stroke has been done ad nauseum. I know it's a lousy answer, but I believe it's reality. It's not just dirtbikes either, btw. Scoots also fall under the same ruling.

Answer 4

Simply the 2-strokes are being phased out by government regulations and the manufacturers know this. The laws will be getting stricter over time and the manufacturers want you to transition to the 4-strokes. That is why they have all their top riders on the 4-stroks so people will want them. That is also why they changed the gas requirements in racing to favor the 4-stokes.

If Ricky had his choice Ill bet he would have stayed with the 2-stroke. He can’t say this but that’s what I believe. IMO

Another myth - 4-strokes are cheaper to maintain.
To keep a 2-stroke race ready it does require re-builds more often but a top-end rebuild kits are cheap.

Wait till you have to do work on the 4-stroke all the costs of the top ends kits and more in one lump sum. Welcome to the world of valves.

Answer 5

Wow. So much mis-information out there.

The 2007 EPA and CARB standards EXEMPT closed course race bikes. According to their definitions as long as the bike does not have a spark arrestor, working lights but does have one of those little "FOR CLOSED COURSE USE ONLY" stickers on it, the bike is legal. End of story.

What we have to determine next is exactly which type of four stroke we're discussing. Play bikes, or race bikes. The old Honda XR's, the new CRFF's (as opposed to the CRFR ad CRFX), the Yamaha TTR's, ect are old school technology born in the 80's or before. These bikes are as most of you have discribed. Reliable, fuel effecient, and left stock, quiet and clean. They are also heavy and underpowered.

Race bikes, what I call RFS (Racing Four Stroke) are a horse of an altogether different story. They feature cutting edge technology, utilizing high reving and high maintaince power plants. As delivered they are...reasonably quiet, and fairly clean. But they are delivered lean for just that reason. Most riders, especially racers and wannabe's will change the exhaust system & richen the fuel delivery up. At this point those bikes are louder than any two stroke this side of the 70's. The sound carries further than a two stroke so they have the capability of pissing people off for miles and miles further than a two stroke. Once the the fuel mixture is richened up to go with the pipe and to gain the extra little bit of performance, these engines are less fuel efficent and are spew more polutants into the air than any well maintained two stroke.

Because thumpers have more parts, moving parts, and wear items than a two stroke they are most definately more expensive to rebuild and require more in between rebuild and in between ride maintaince to be kept in good mechanical shape.

Not to mention they have to have nearly twice the displacment to make the same horsepower as a comparitive two stroke.

Are they the future? The immediate future, yes. Sales numbers, and ONLY sales numbers are driving that. But it will change. History always repeats itself. It wasn't that long ago that the big four stroke singles from BSA, CCM, Triumph and Jawa ruled the off road world. Then these pesky little two strokes showed up (and were not given a displacment advantage in racing) and changed everything.

It will go full circle again. Look for fuel injection, variable ignitions, and manufacturing materials that allow extremely lean mixtures in the future. Noise will ultimately be the demise of the current generation of four strokes.

Answer 6

Definitely ahead of the 2 strokes.
BUT, 4 stroke are probably the bikes of the present, since current improvements make them as strong and as light as the old 2 strokes.

Answer 7

Well they are easier and cheaper to maintain but i love the power band on two strokes, they are so much fun, especially on street bikes. Four strokes have better emissions and the cops can hear two strokes from miles away, i have an XL 600 and that thing is loud but the cops don't care b/c they really like to crack down on the kids that are riding thier two strokes in quiet residential neighborhoods.

Answer 8

because they are easier on the environment than the 2 stroke..believe me, I want the 2 strokes to stay...

Answer 9

It's simple - less emmissions. 2 stroke outboard motors for boats are already banned on many lakes and inland waters and now are getting tough to find. 2 stroke bikes are next...

Answer 10

It's just the politically correct way of thinking i guess, ya know - cleaner emmisions , save the earth , all that....