Whats the point buying a two stroke anymore?

[mtk]

AJ,

The factories wanted MotoGP to move to four-strokes for the same reason dirt bikes are moving that way: now all their R&D money spent on racing has applications outside of closed-course competition. Two-strokes are dead as a street technology. So pouring R&D money into them in racing makes little sense. Why invest millions into 500GP, with no corresponding street payoff in R&D (or marketing "halo" effect)? What you learn with four-strokes in MotoGP can be applied to the street product lines. Or in Honda's case, what they learn in F1 can be trickled down to all their other products.

Now that same R&D knowledge can be applied to the dirt bike lines since they use the same four-stroke technologies.

But you're points about costs and profits are also quite valid.

As for exhaust emissions, that one isn't quite cut and dried. Two-strokes are notoriously bad on hydrocarbon (HC) emissions due to burning premix. Four-strokes don't emit nearly as much HC emissions as a pinger. Also keep in mind that the EPA could screw up a wet dream, so assuming these folks know good science (or their ass from a hole in the mud) is a BAD assumption. In fact, in more than one case it has been pointed out that they have either IGNORED data they didn't like or cooked the data to get the conclusion they wanted. After all, if they announced that the emissions "problem" was fixed and was good enough, they'd all then have to find real jobs. See examples of the EPA requiring discharge water from plants to be cleaner than the water they took into the plant in the first place. As in, run a pipe into a river and back out again and you're in violation of EPA requirements on the discharge end.

Sound science and the EPA rarely collide in the same sentence.

 

[jsned]

bimmernate, if you are just getting into riding, and it sounds like you are concerned about money. go cheap on your first bike.

 

[FruDaddy]

How much time do you have on a 4-T? No, not surfing the web time, actually time.

I got to ride one today, but it didn't impress me. The owner thinks it's a beast, I say I can turn better laps on my smoker. The power was OK, but I still needed to clutch it (owner recommendation) . Also, the start procedure sucked, it took too long. "Pull this knob, push the kicker down, let it up, pull this lever, push the kicker down a little, let it up, release the lever, grab the crossbar, give it a kick, push that knob back in." Sorry, I'll pass, but in the bikes defense, it was a YZ426 with a suspension that was way too stiff for me. I do now understand why the AMA upped the displacement advantage.

 

[Okiewan]

Not even gonna bother.


D E N I A L.

 

[mxrider76]

I have had a xr 80 for four years. One topend. I ride all I can(almost every weekend) pour gas in it and check the oil. Same with my suzuki dr 125 check the oil and filter oil the chain pour in gas and hit the electric start and off I go.

 

[BDAY]

I have had a xr 80 for four years. One topend. I ride all I can(almost every weekend) pour gas in it and check the oil. Same with my suzuki dr 125 check the oil and filter oil the chain pour in gas and hit the electric start and off I go.

those bikes are in a completely different class, they are trailbikes. this discussion is about motocross bikes, the technology is completely different.

 

[IndyMX]

I live just outside of Indy and am not having too much trouble finding places to ride. However, the places I can ride are a pretty good drive from home. But, that has really nothing to do with my bike being a 2 Stroke.. It just has to do with the fact that there probably isn't anywhere good to ride in any big metro area.

There are plenty of places to ride if you are willing to spend some time getting to them.

 

[BRush]

:::::::rant on::::::::

...as for my personal rant in this thread, lets all please recognize that emiissions are not the reason for the decline of 2 strokes...

...but you cant ignore the fact that those huge R&D dollars could have been thrown at the current 2 strokes and with all the Ti componentry and all the trick engineering,
some amazing bikes be put out as well?....

::rant off::

One man's rant is another man's sweet reason. If we ever run into each other, I'll have to buy you a beer. Well said!

 

[scatman]

Does it really matter if its a 2 or 4 stroke? Get what makes you happy. I chose a 2 stroke because thats all I ever rode back in the day. The only 4 strokes we had were trail bikes like the XR's. If you raced motocross you just picked a color and decided on 80,125,250. Would I buy a 4 stroke in the future?...maybe. Im just having a hard time getting used to the sound of them. It doesnt seem right to me, but then again...I havent raced in 12 years so who am I to judge. :laugh:

 

[Hooner33]

I see we have ran away from the 1st question that was asked by someone who is very new in the sport. Im sure he didn't want to hear about the 4t and 2t universal battle. But hey it all comes down to what you want. If the 4t makes you happy with what ever it is, then go with it. BUT IF the 2t makes you happy becasue its what you can buy then go with it.

The way I see it is, if you can afford a Cadillac and maintain one ( and go in debt with one) then go ahead.

But if you can afford a something thats a little cheaper and easier to maintain then by all means, DO IT.

To set things straight, I own a 2t and love the thing to death. The maintaince I can do myself. I have ridden 4t and love what they offer you. I have also have helped my buddy maintain and rebuild his 4t. He loves it and swears by it. Its all what you can handle. The way I ride and how agressive I am its a 2t if for me.

so for now, lets all settle down and have fun with what we own. YES, that works in a liberial place-o-fun. But Im a very strong repubican, GOD BLESS THE 2T. :laugh:

 

[Brian]

Its really too bad that people try to pass off myths as truth when trying to help someone new to the sport decide what they should buy, for whatever reason. Two-strokes don't "suck" and neither do thumpers. They each have their own advantages.

Personally, I ride a two-stroke. Why? I feel that for my riding style/conditions, the benefits outweigh those of a four-stroke.There are a few things to consider that can't really be disputed, you just have to decide what is more important to YOU.

Four-strokes do require more maintainance. Oil changes are more important and should be done more often. Valve adjustments should be done regularly to help extende the life of the bike. There are more moving parts, and if something happens to go wrong, it will be more complex and more exoensive to fix. Two-strokes like to have fresh rings every so often, but this is a very simple and inexpensive job compared to doing the same work on a four-stroke.

Four-strokes tend to be louder also. They have a deeper tone that has a much more omni-directional effect that carries farther and has the potential to bother others.

Four-strokes weigh more, and as a result , handle differently than a two-stroke of matched power.

Four-strokes have less power than a two-stroke of equal displacement, but more power than a two-stroke they are compared to. This is probably the number one reason the thumpers are so popular. If you are allowed a bigger motor with more power to compete against a smaller motor with less power, why not do it?

Two-strokes vibrate more. Some guys care, some don't.

Two-strokes smoke and pollute more. Does anyone who actually rides a dirt bike care? The eco-nazis are primarily the ones concerned about this.

Four-strokes are easier to ride. They have a smoother power delivery and are more predictable.

Two-strokes are less expensive to start with. Less parts, less technology, less expense.

Two-strokes are more finicky about jetting. They will foul plugs, spooge, and not run cleanly when jetted incorrectly. Four stroke like to be jetted well, too, but they won't foul plugs or blubber if they're not.

The whole two-stroke ban has been blown way out of proportion. It will happen, but likely not anytime in the near future. Even when they stop being manufactured, you won't be stopped from riding one that you already have, except in CA. Everything is wierd over there :laugh: I wouldn't let this influence your decision at all.

Thats about all I can think of off the top of my head. I'm sure there are many more positive and negative aspects on both sides of the fence. Just look them over and see what fits you best.

 

[RADRick]

I posted the following elsewhere on DRN, but since the subject has come up in this thread I feel compelled to repost it.

Begin quote - Pardon me for jumping in, but I keep seeing this statement about a "double displacement advantage" not being fair and it just irks me. First off, displacement is simply a mechanical measurement. When comparing motorcycles of different engine technologies it really isn't a relevant measure of comparison. That's why the AMA and other sanctioning bodies basically ignore it when determining what bikes race in what class and instead concentrate on the engine type.

A 2-stroke has a power stroke on every revolution of the crankshaft. A 4-stroke has a power stroke on every other revolution of the crankshaft. Despite the seeming advantage of displacement of a 450 4T over a 250 2T, the 250 actually does more work at the same rpm making it equally as powerful. The 4-stroke gains a torque advantage because of the extra displacement, but that isn't necessarily a performance advantage. Think of it this way: for every 1000 rpm a 4-stroke puts out only 500 power strokes. A 2-stroke will put out twice as many power strokes. Allowing the 4-stroke a larger displacement puts the two on a more equal footing. (Although I'm not convinced that double or near double displacement is the correct calculation the AMA should be using.)

Since the 4-stroke also has a valvetrain to deal with, much of the power advantage gained by the larger displacement is used on turning the cam and chain and overcoming the resistance from the valve lifters, springs, much heavier flywheels and higher combustion chamber compression. To stay properly lubricated the 4-stroke must also use some of its power to turn an oil pump. A 2-stroke has no valvetrain or oil pump to rob power and it has less cylinder compression and lighter flywheels to overcome so that more of its power is going to the rear wheel. There's also the added weight of a 4-stroke. When compared solely by output, a 125 2-stroke puts out about the same horsepower as a 250 4-stroke. The same is true of a 250 2T and a 450 4T.

This is why the "double displacement advantage" is a myth. The 2-strokes are losing (lost) ground in racing not because they can't compete with bikes twice their engine size, but because the superior torque characteristics and broader powerband of the 4-stroke favor them and because tracks are now being designed more for the 4-strokes than the 2-strokes. - end quote

And to the poster who decried the factories abandoning 2T R&D: What would be the point of continuing it? With no end user application other than closed-course racing, what purpose is there in developing a cleaner 2-stroke engine? Factories race for one reason, to develop products they can market and sell profitably. 4T technology is the dominant force in auto and motorcycle design, both street and off-road. Why pour money into a technology that has such limited application? :coocoo:

As for the ecological arguments, I agree that we are trading one problem (smoke of a 2T) for another (sound of a 4T). But a non-rider can see a photo of a 2T rider and easily find something to dislike about them when they see smoke coming out of the tailpipe. A photo of a 4T rider doesn't automatically elicit a negative response.

 

[BRush]

With no end user application other than closed-course racing, what purpose is there in developing a cleaner 2-stroke engine? Factories race for one reason, to develop products they can market and sell profitably. 4T technology is the dominant force in auto and motorcycle design, both street and off-road. Why pour money into a technology that has such limited application?

Well, to win races and sell motorcycles would be one very good reason. Winning is a powerful marketing advantage. I agree with you about 4T technology being where the R&D money is being spent today. Why is that? Back in the day, four strokes were not competitive with two strokes of equal displacement. The rules were tweaked to address that imbalance, basically by handicapping the two stroke and tipping the scales in the other direction in order to encourage 4T development. If those changes had not been made, it is quite likely that two strokes would still rule the racing scene today. Why? You said it yourself:

A 2-stroke has a power stroke on every revolution of the crankshaft. A 4-stroke has a power stroke on every other revolution of the crankshaft. Despite the seeming advantage of displacement of a 450 4T over a 250 2T, the 250 actually does more work at the same rpm making it equally as powerful. The 4-stroke gains a torque advantage because of the extra displacement, but that isn't necessarily a performance advantage. Think of it this way: for every 1000 rpm a 4-stroke puts out only 500 power strokes. A 2-stroke will put out twice as many power strokes. ..... Since the 4-stroke also has a valvetrain to deal with, much of the power advantage gained by the larger displacement is used on turning the cam and chain and overcoming the resistance from the valve lifters, springs, much heavier flywheels and higher combustion chamber compression. To stay properly lubricated the 4-stroke must also use some of its power to turn an oil pump. A 2-stroke has no valvetrain or oil pump to rob power and it has less cylinder compression and lighter flywheels to overcome so that more of its power is going to the rear wheel. There's also the added weight of a 4-stroke. When compared solely by output....

Those tech advantages are still there for clever engineers to exploit. And if two strokes cleared the emissions hurdle and came to dominate the racing scene again, the market would follow.

 

[RADRick]

Well, to win races and sell motorcycles would be one very good reason. Winning is a powerful marketing advantage. I agree with you about 4T technology being where the R&D money is being spent today. Why is that? Back in the day, four strokes were not competitive with two strokes of equal displacement. The rules were tweaked to address that imbalance, basically by handicapping the two stroke and tipping the scales in the other direction in order to encourage 4T development. If those changes had not been made, it is quite likely that two strokes would still rule the racing scene today. Why? You said it yourself:



Those tech advantages are still there for clever engineers to exploit. And if two strokes cleared the emissions hurdle and came to dominate the racing scene again, the market would follow.

The fact remains that the 2T, even if it could be made clean enough to pass emissions (which I doubt), would not have the broad appeal that the latest 4T models have. There are many riders like myself who got back into the sport solely because of the newer 4-strokes. Having given up racing long ago I wanted something that was easier and more fun to ride with less chance of injury. Many riders I come in contact with say the same thing. These new 4T bikes have extended their riding while still giving them the performance they want. Racing isn't everything to the vast majority of riders. The balance was tipped because the 4T provides manufacturers more sales potential, not just because of any emissions regulations or sanctioning body moves. Dirt biking is exploding in popularity, and not just because it is getting more TV coverage. The newer 4-stroke models are helping to bring new riders into and old ones back to the sport. Riders who likely might not have if 4-stroke technology had not developed to where it is today.
I'd hate to see 2-strokes disappear completely from the motorcycle milieu, but at a time when our sport is under attack from so many fronts, it's a small sacrifice to make to eliminate such an obvious weapon from the arsenal of the eco-weenies. In a world where perception is everything, fewer people seeing a smokey tailpipe running through the woods or on a racetrack is a good thing. We can lament the demise of the 2T all we want, but at the end of the day it will likely do more to further our sport than sticking with the technology would have.

 

[2stroke]

I dont even belong in this converstation, (My newest bike is 31 years old). They are all smokers, even my streetbike.

Its funny, when I was a kid, my Brother tried to explain the whole 4s vs 2s issue...he told me "2 stroke is power, 4 stroke is reliabiliy"....This was around 1978 or so, and I had always pretty much agreed. Its funny how that has changed though. The hyper 4 stroke racing bikes put out awesome power, Jeezus, ever been hit in the face by a 426's exhaust from like 30 feet away? ;) And of course they take a little more to keep up on, I guess as they have struggled to make the valve train lighter, and have pushed the RPMs into adn beyond what used to be 2 stroke only territory.

Personally Ive never been on a four, except my old XR200 and my buddies TT500. Now thats a scary bike!

If I was to buy a brand new bike, with one of them there new fangled mono shocks and all......Id have to search for a back model KX500. :nod:

Bikes are like guitars and women. Every type has its merits, and no matter how many you have, its always fun to play around with some other ones. :laugh:

 

[just_a_rider]

I think the sound of the 4t's rock! I have a 2t and don't ever plane to be without one but I also want a KXF450r. The valves of the 4t, seems like thats all I ever here about. 4t's aren't made to turn the rpm's of 2t's although some think so and you can hear them cutting out over jumps being over reved thus streaching the valves causing premature valve adjustments. You can get a valve job around here for about 30 to 40 bucks. It's all in the rider that depends on how often for this and that on either style bike.

 

[Ol'89r]

4t's aren't made to turn the rpm's of 2t's although some think so and you can hear them cutting out over jumps being over reved thus streaching the valves causing premature valve adjustments. You can get a valve job around here for about 30 to 40 bucks. QUOTE]


:coocoo: :blah: :blah:

Jeeze! Where do these guys come from? :whoa:

 

[motometal]

In a world where perception is everything, fewer people seeing a smokey tailpipe running through the woods or on a racetrack is a good thing. We can lament the demise of the 2T all we want, but at the end of the day it will likely do more to further our sport than sticking with the technology would have.

Smokeless oil and/or proper jetting addresses the smoke issue. Your post didn't relate to the increasing noise problem...when's the last time you heard of a riding park shut down because of the smoke? I disagree with your point that the smoke is a "real" issue in the public's perception, especially in comparison to noise. What about all the busses, trains, and semi trucks belching out smoke...we'd better get rid of those too, right?


Regarding the fours being so much easier to ride, yes and no. Depends on the circumstances. 450 vs 250 (2 stroke) for example, you can run a gear high on the 250 and the power is pretty tame, but the 450 has power right now, regardless. This is also related to the continuing popularity of the 2's for the woods, hare scrambles etc. Actually, easier to ride there. Sure, you can buy a "woods" four stroke, but now you have a detuned motor and extra weight that you don't need, compared the the 2-t.

Also, considering which tends to stall more frequently and which is easier to start, in my opinion this would actually be a turn-off if I was getting back into the sport after many years. It's hard for me to see increased maintenance, tricky starting proceedures, having to remove the fuel tank to change a spark plug, etc. as "marching forward" technology wise (although I know that in a backwards way, it is).

 

[dezryder]

Valves, valves, valves

It seems that valves are a really big issue when you hear four vs two stroke talk.

Personally, I cut my riding teeth on a four stroke. (Honda 250 scrambler) Then bought a new 250 when Honda came out with the XL's. (First four valve single on the market)

I currently own two 2-strokes. My last 4 Stk was a '87 Husky 510. I loved that bike and only sold it because I heard from reputable folks that parts would not be available because of the Cagiva buy out of Husky. (Sold the bike for $300 less than I paid for it!)

I had the 510 18 months, with a ton of trail miles and a couple of hare scambles, never touched the valves after the initial break in adjustment. (Well, I may have checked them once)

Valves are over rated as a maintenance issue on four strokes. You don't hear too much about the power valves on two strokes as a maintenance issue. But they are just as well.

If I was in the market for a new scoot, I'd by a four stroke in a New York second. It'd have to be a Katoom though!

 

[motometal]

power valves on a two stroke can be an issue. I had a '96 RM250 with a sticking powervalve, drove me nuts and ended up being a $5.00 bearing that had collected enough spooge to tighten up and stop turning when warm, but worked fine when cold.

The KX80/85/100 had a habit of breaking the little cross pin in the powervalve. The part was cheap, and the bike ran pretty well without it actually...still annoying though.

Other than these problems, out of about 10 other bikes I've owned with powervalves I have never had to "service" the powervalves other than during routine top end service. This is just cleaning, no parts (with the powervalve). Proper jetting and clean burning oil make a big difference here.

The powervalve, by nature, leads a much, much easier life than valves on a 4-t, which are hammering open and shut thousands of times per minute.

 

[dezryder]

The powervalve, by nature, leads a much, much easier life than valves on a 4-t, which are hammering open and shut thousands of times per minute.

Agreed.

Whenever I read discussions re four strokes however, valves always come up as a BIG issue. Like they are scary, and like you need to adjust them once a month or something. Which just isn't the case.

With all the folks that have had a two-stroke power valve grenade itself, possibly taking out the piston and maybe the cylinder too, you'd think they would get at least an honorable mention as a maintenance issue in comparison.

Just my two cents.

 

[RADRick]

Smokeless oil and/or proper jetting addresses the smoke issue.

Most riders will use the oil they know or see being used by others. It's probably too late to educate them on the alternatives.

Your post didn't relate to the increasing noise problem...when's the last time you heard of a riding park shut down because of the smoke? I disagree with your point that the smoke is a "real" issue in the public's perception, especially in comparison to noise. What about all the busses, trains, and semi trucks belching out smoke...we'd better get rid of those too, right?

I still have to disagree with you. Many non-riders never actually come close enough to a track or riding area to know what the noise issue is about, but they will see a photograph or televised event showing a smoky motorcycle and have it leave an indelible negative perception on them. I'm not saying noise isn't an important factor, but the smoke is very much a real issue. I've been to enough city council meetings for proposed parks and tracks to hear it voiced by the opposition.

Regarding the fours being so much easier to ride, yes and no. Depends on the circumstances. 450 vs 250 (2 stroke) for example, you can run a gear high on the 250 and the power is pretty tame, but the 450 has power right now, regardless. This is also related to the continuing popularity of the 2's for the woods, hare scrambles etc. Actually, easier to ride there. Sure, you can buy a "woods" four stroke, but now you have a detuned motor and extra weight that you don't need, compared the the 2-t.

Well, I'd just say that we have differing opinions on this. I know a lot of older riders who are only still riding because of the current technology of 4T engines, myself included. I also know many former 2T riders who are very happy on their 4T bikes and have no desire to go back. Different strokes for different folks.

Also, considering which tends to stall more frequently and which is easier to start, in my opinion this would actually be a turn-off if I was getting back into the sport after many years.

You sound like someone who listens way too much to the Speed/OLN race announcers who can't let a moto go by without pointing out the vagaries of a stalled 4T. This may have been true back in 2001, but today's production 4T is much easier to start. Don't compare them to the highly tuned, race gas running bikes the pros are racing. They are so close to the limits of stoichemetry that a mere 5 degree change in ambient temperature can wreak havoc with them.

It's hard for me to see increased maintenance, tricky starting proceedures, having to remove the fuel tank to change a spark plug, etc. as "marching forward" technology wise (although I know that in a backwards way, it is).

Increased maintenance to a 2T, perhaps, but by no means enough to drive a choice difference. As for "tricky starting procedures," are you kidding me? Besides the addition of an easily reached hot start lever and the need to get a complete stroke out of the kickstarter, what is trickier than the 2T? And changing the spark plug is a non-issue. A properly jetted 4T can go a whole season or more on a single plug. 2T plugs foul regularly and need easy access because of it. Yes, the 4T spark plug is a pain to get to, but it isn't likely to be something you need to do very often.

 

[Rich Rohrich]

Don't compare them to the highly tuned, race gas running bikes the pros are racing. They are so close to the limits of stoichemetry that a mere 5 degree change in ambient temperature can wreak havoc with them.

Did you honestly think you could post that without someone throwing the BS flag? :rotfl:

I'm wondering based on your usage if you even KNOW what stoichiometry means. :whoa:

...or

Maybe this just warrants further explanation on your part so we can all understand. ;)

 

[RADRick]

Did you honestly think you could post that without someone throwing the BS flag? :rotfl:

I'm wondering based on your usage if you even KNOW what stoichiometry means. :whoa:

...or

Maybe this just warrants further explanation on your part so we can all understand. ;)

As used, stoichemetry refers to the ratio of fuel to air for proper combustion in an ICE. That ratio is approximately 14:1 air to fuel. Stoichiometry is the reaction of chemicals in quantities and combination. Sorry if I threw you a curve ball.

 

[Rich Rohrich]

As used, it refers to the ratio of fuel to air for proper combustion in an ICE. That ratio is approximately 14:1 air to fuel.

Well it's good to see you know how to use Google. So "splain" this to me Lucy, what does that have to do with the point you were trying to make?