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Whats the point buying a two stroke anymore?
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Posted by: bimmernate

So I am a newbie, but I have a question. I was researching some stuff today, being that im in the market, and the bikes in my price range are all two strokes.

I read that this year the govt. is banning two strokes newer than 98 from parks, etc. Well, what the heck, and I have also read on this board that everyone is losing places to ride. Noise being number one. I suppose emissions is another reason. I suppose that I could find private tracks, etc. But I dont have alot of connections in the business, and govt. outdoor riding parks would seem like a good place if all else fails.

Anyway, I cant afford a four stroke right now, and I dont want to get stuck with a bike that I cant ride anywhere...I was planning on taking it up north to the dunes around the great lakes, and im sure those places arent as worried about things as a trail park on the outskirts of a city with houses by it, but I just dont want to buy a bike and have it sit. It sort of saddened me a little, whats going on here?

I read this in one of those 101 projects to do to your bike books.

thanks.

Posted by: larosche

2 strokes are not becoming banned (unless you live in CA where everything is weird). The BEST reason to buy a 2 stroke is reliability.
4 strokes (modern) require big cost rebuilds every year. You can ride a 2 stroke for 4 years without ever changing the rings.
Also you need to keep on top of the valve adjustments (not easy on some bikes like Honda).
If money is the primary issue then stay away from 4 strokes.
RAD DAD

Posted by: bimmernate

Oh, so I can still ride them quite easily then around the country besides cali. Hmm you have brightened my outlook, the book should have been more specific. Excellent, I can keep looking for a good bike then, and its good to know about reliability also because this will be a first bike where I should learn the machines first.

Posted by: Okiewan

Quote:

4 strokes (modern) require big cost rebuilds every year.

Sorry, that's BS. as is:

Quote:

You can ride a 2 stroke for 4 years without ever changing the rings.

I suppose if you race the 4-t every weekend of the year and ride the 2-T about 10 hours a year, you could be right. What does your manual say about top ends? 20 hours? Seriously, this is internet wives-tales spewed by 1) people who don't have a 4-T, 2) People that don't want to buy one and 3) are justifying keeping the 2-T.

IF you ignore maint. and nuke a 4-T, it will cost more than the same situation with a 2-T. This is true. IF you maintain your 4-T (yes, theres more to do, as in checking valve clearences and changing oil more often) it will give you just as much love as a 2-T.

Here's a internet forum tip: When someone says general stuff like that about four strokes, look at what they own. 9 out of 10 times, it will be a 2-stroke owner making comments like that. "I know a friend of a cousin's friend who had a... " or, they just read it somewhere and it sounds good.

All that said, either way you decide to go, it's all good.

Posted by: jmics

Two strokes are about as illegal as carburators on cars . They aren't ,they are justextremely difficult to try and keep up with today's emission standard's.

"F you ignore maint. and nuke a 4-T, it will cost more than the same situation with a 2-T. This is true. IF you maintain your 4-T (yes, theres more to do, as in checking valve clearences and changing oil more often) it will give you just as much love as a 2-T."

I wondered about this

lets say you had the bike for a few years... 1 trashed four stroke cylinder isn't as much as 1 trashed 2 stroke cylinder and from personal experience the amount of time and energy spent trying to straighten out an expansion chamber let alone having to buy one compared to a complete head for a four stroke

just thinking about my wallet out loud

Posted by: FruDaddy

Two strokes are a little lighter and therefore more agile (easier to change directions). Due to the increased number of moving parts and the overall complexity, there are more things to maintain, so the time and cost of maintenance is going to be greater on the 4-stroke. Also, the initial price of a four stroke is a bit higher. Four strokes tend to be louder. Then there is the fact that the thumpers are harder to start when hot(correction necessitated by temporary stupidity) (hot start lever required). Yes, I ride a 2-stroke, if you wanna know why, read this post again.

Posted by: Okiewan

LOL.
My point is made.

A hot start to start a cold bike? One week, no starting. Blip the throttle 2x, pull the choke (opposite of the hot start) 2 kicks, it's running. I'm sure your 2-T starts much easier tho.

How much time do you have on a 4-T? No, not surfing the web time, actually time.
How much have you spent maintaining a 4-T vs. your 2-T?

Posted by: FruDaddy

Oops, typing error.
Yesterday, after two weeks, the starting process was: turn on the gas, pull the choke, kick it twice, turn off the choke, let it warm up while I put on my helmet and gloves.
Nobody has been stupid enough to let me ride their thumper yet, but I hear that they are much easier to ride. I was just providing the reasoning behind my decision.
I am also certain that I will get more than enough wrench time on thumper when my son steps into the league of the big bikes. By then there will likely be no 125's left.
I am not anti- 4t, we all choose to ride what we like. In fact, I believe that I have recommended the thumpers to a few people here (but probably not Honda's, I think they are overrated). It's Rob that hates the thumpers, I just choose to not ride them.

Posted by: Okiewan

Quote:

I just choose to not ride them.

Obviously, no one can argue with that.

Quote:

Honda's, I think they are overrated

Okay, now you've done it, them's fight'n words!

Quote:

It's Rob that hates the thumpers

Another guy with lots of different bike/thumper experience that is quick to pass along web fantasy

Posted by: FruDaddy

Yep, ride green, ugly color, great bike

, or go blue, poor design (IMO) but great color .

Posted by: Okiewan

Contrary to popular belief, one of my favorite bikes was my 99 KX 250. I wish I still had it.

Posted by: FruDaddy

That proves my theory that deep down, everyone has a secret soft spot for the smokers. My secret, I actually like the 4-stroke sound better, they're just a bit too loud. Then again, that's what most think about my street bike.

Posted by: Okiewan

Quote:

That proves my theory that deep down, everyone has a secret soft spot for the smokers.

For sure for those of us that remember when the 2-T was the "New Thing" in dirt bikes... we grew-up riding 2 strokes, we learned how to ride a dirt bike on them. But honestly, the thing I liked most about the KX was the whole package, it had a GREAT Eric Gorr big bore motor and great suspenders (MX-Tech, the first time I ever had suspension dialed-in just for me) along with a TON of other goodies that just made a great bike. EXCEPT those DAMNED side panels that hooked my boots all the time.

My bottom line? I really don't care rather it's 2 or 4, it is afterall a dirt bike. What DOES bother me, is the passing of rumors of massive work and dollars owning 4-T's by people that have no place saying it, as in, they've never owned or maintained one, they just pass along the internet crap they "read or heard somewhere".

Posted by: robwbright

For once Okiewan and I are in virtually total agreement in this thread - except for that Rob hates the thumpers thing. It's more like I really like 2 strokes.

For the sake of clarification . . .

I don't hate thumpers. I think they are fascinating technology and at such time as I can afford to pay someone else to do the maintenance, I may well buy one - but I've said that before.

My opinion on the thumpers has softened over the last year. However, my objections were based on the fact and/or allegation that they require more maintenance and that they are more expensive.

In spite of the fact that I am now an attorney, my income has not increased significantly - yet. It takes quite some time from the time you get a client to the time that you get paid - with the exception of retainer fee clients - and only about 25% of ours are that kind. I have a 6 figure debt from law school and college. I have a wife and child and very little extra time.

Thus, assuming that 4 strokes do require more maintenance and are more expensive to maintain, they are not feasible for me. I spent Friday evening working on the bike and I couldn't race on Saturday because I spent $50-70 on other stuff for the bike. Thus, I'm trying to run on a shoestring budget - not a good idea on a 4 stroke if my impression of them is correct.

As to recommending 2 strokes to others, anytime I have seen a person mention money being a problem, I recommend a 2 stroke. Perhaps I'm wrong. I have recommended 4 strokes on occasion.

The 4 friends I have that recently purchased 4 strokes have told me that they aren't really concerned about maintenance or checking valve clearances. I hope that they don't run into a serious problem at some point.

Maybe it's just in this area of the world, but most people around here tend to take that approach to things - and my brother is the worst offender of all. Most here do LESS maintenance than virtually anyone on the board. As such, 4 stroke MX bikes probably aren't a good idea for those people.

Anyway, I don't hate thumpers. Are they easier to ride? Undoubtedly.

However, I do hate the displacement rule. Without it, it wouldn't be feasible to use them for MX racing.

As to whether the 4 stroke design is better, it is an amazing, high tech design. However, get back to me when they figure out a way to make near equal power with equal displacement. Then they will TRULY have a great design.

I suppose I will eventually have to give in to the reality of the rule.

2007 or 2008, I suppose.

Posted by: robwbright

And no, I haven't maintained an new 4 stroke, so Okiewan, let me know how much more $$ and time is really required to maintain a 4T 250 vs. a 2T 125.

I have ridden the 4T's. As noted, they are easier to ride. I've said that repeatedly before. Not shifting for the whole track is certainly an advantage.

Posted by: FruDaddy

My belief that the 4t's require more time and money for maintenance isn't based as much on what I've read or heard, as the facts that are there. Assuming that all MX bikes require basically the same maintenance, air filter, chain, tires, suspension, carb tuning, oil changes, and the occasional top end. The addition of the cam and valves will create extra work. When it comes time to do a top end, the head must be removed, with the 4t the cam chain must be moved out of the way, on reassembly, the cams must be aligned. Assuming equal skill, the thumper will require more time for a simple top end. Also, there is the time involved in adjusting the valves. More moving parts, also means more parts wearing out, which equates to more parts having to be purchased. And this is where the money comes into play. Also, a larger piston requires more material to manufacture, thus costing the manufacturer more money to make. I haven't actually checked the sizes of all of the bores, but I know the extra 200cc's isn't all stroke.
One thing that bothers me is how so many people seem to think that 4-strokes require no maintenance at all. These are the ones foolish enough to put the YZ450F in the same category as a TTR125.

Posted by: cr125freak

A) a two stroke top end can be put in for $100 and 2hours of your time (depending on your skill)
B) VERY fun to ride
C) cheap if you buy them used
D) fast if you know how to ride them
E) Can be made very fast for less money than a 4 stroke
F) Sounds great- lol
G) Smells even better- lol
H) You can participate in fighting the revolution
I) Do i need to continue?

Posted by: XRpredator

Quote:

Originally Posted by FruDaddy

That proves my theory that deep down, everyone has a secret soft spot for the smokers.

Deep down I have a seething hatred for the ring-ding, smoke belching 2 strokes.

and it don't matter how many words Perry Mason puts in a post, 2-strokes still suck.

Posted by: larosche

I stand by my words on the 4 stroke thing. I had a 2001 KTM 200 EXC. Raced it about 20-30 time/year. I never changed the ring and had it for 3 years. I had a KDX200 that lasted 4 years with only 1 ring change.

I then purchased a 2004 Honda CRF250X. I owned the bike for 18 months. It was in the shop for 4 of those months. It ate the starter after 3 months (Honda did cover this cost but it was in the shop for 2 weeks). Then the valves started to go out of adjustments at 11 months. They required 3 more adjustments then went out completely. I had them replaced (all work done at a dealer). 3 rides later the valves went out again. Honda then replaced the head, valves, seats, etc.

My A riding buddy replaces his whole top end (piston, valves, etc) every year. I race a little more than he does.

My 2006 KTM 200XC-W is about 1 year old. Has way too many miles to talk about but I only have to pour gas into that puppy.

Sorry but 4 strokes are not ready for racing Enduros and Hare Scrambles at the rate I ride.
Ed Larosche

Posted by: cujet

I ride my 2 stroke bike in Ocala National Forest. There are plenty of 2 strokes still operating there. The rangers do not care one way or another. They do care about proper registration and paperwork, USFS spark arrestor, and that you pay for the day you are there.

Chris

Posted by: bimmernate

I have learned alot from this thread, its good it has taken off. I am a little bit worried about the continuing legality of a two stroke. You see, I have a cottage up by Silver Lake MI and that will be my primary place of riding, plus some dirt tracks as I find them. Problem is, what if those places such as Silver Lake start outlawing 2Strokes? Im left with a bike that I cant ride anywhere, which is my overall theme of asking the original question. I am concerned that may be the case, in places other than CA. Any advice? A good used 250 or somthing is all I can afford (2 stroke obviously)...

thanks again.

Posted by: cujet

I never base a decision on a "what if".

As far as I can tell, you will be using this as a play bike. Obviously, the more powerful (twice the size) 4 strokes are winning a lot of the races. So, to be competitive, a 4 stroke might be the way to go. For a play bike, 2 strokes are awesome.

Not sure I would base my purchase on the risk of tracks changing the rules. 4 stroke displacement rules are changing in some forms of racing right now. Also, 4 stroke noise levels are generally higher and it is my opinion that the 4 stroke noise carries further. Not a good thing when riding at the local "pit".

Then there is that wonderful, incomparable feel of a super light weight, powerful 2 stroke

but we won't go there in this discussion.

Chris

Posted by: Steve St.Laurent

I wouldn't worry about 2 strokes being banned any time soon here in Michigan and especially at the dunes. The primary concern at the dunes for quite a few years has been noise levels and 2 strokes are generally easier to get quiet than the mx 4 strokes (IMO). The vast majority of bikes that you see on the trails around here are still 2 strokes and the CCC is well aware of that and would fight any initiatives to ban them. I just bought a brand new 2 stroke in may and have no concerns at all that they will be going away any time soon.

Posted by: FruDaddy

Quote:

Originally Posted by bimmernate

A good used 250 or somthing is all I can afford (2 stroke obviously)...

Then it's what you should go after, better riding than wishing.

Posted by: AJ Waggoner

Certainly for riding Michigan's Silver lake dunes .
your first idea is fine.

a good used 2 stroke 250 would be great for there, both in performance and price/ value

as far as worrying about the 2 stroke future , thats very over exaggerated ,
certainly for where you plan to ride.
there is absolutely no issue with riding a 2 stroke in michigan now, nor in the near future.
anything can happen down the road, but thats far enough in the future that you may be in the market for ten bikes between now and then?

the "banning of all 2 strokes" , even in cali, is over blown on the internet rumor mill..

you can buy a brand new 06 YZ250 or CR250R and red sticker it to ride in the cali OHRV riding areas.
yes you are limited to a red sticker , instead of a green sticker, and it limits you from riding in certain times
( mostly the hottest part of the summer when most riders are avoiding riding anyway from the heat.)

Also if you buy a 2002 Cr/YZ/RM/KX 2 stroke, it is green sticker elgible in cali..
so if your looking at used bikes even the cali red sticker rule would not effect you at all unless you were dead set on buying a 2003 or 04 instead of an 02 (most bikes changed very little those years anyway)

My point being that your worries and fears , would not even be realized in Cali which has by far the most stringent regulations..

:::::::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.
If you think so, please test a modern 4 stroke exhaust, against the bike class it is made to compete with, compare apples to apples, and get back to me.
Twice the displacement..with jetting and cam tuning to optimize performance and get every once of power out of the engine..
does NOT generally make a much cleaner burning machine?

both platforms are great bikes!!!!!!!!!!!!!!!!!!!!
with distinct advantages and disadvantages.

but please lets not buy into the pablum offered up as an excuse for the manufactuers to sell you a higher priced bike, with higher priced parts.With similar maintenance schedules.Your trade in value is often less..
The manufactuers make more money all the away around.
This is all about the benjamins,not saving the enviroment.

It may indeed be a better bike for many..
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?
Honda years ago, once had a 2 stroke Cali carb/ emmision compliant engine designed around pre detonation principles.. very artsy stuff.
It worked very well and they won some big dez races with it.. patented it and moth-balled it.

The current crop of diesel bikes is awesome, just dont think they couldnt have been 2 strokes that ran cleaner (than the amped out 4 stroke) and were better (lighter) and perhaps even torquer with availible technology.

::rant off::

Posted by: 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.

Posted by: jsned

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

Posted by: FruDaddy

Quote:

Originally Posted by Okiewan

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.

Posted by: Okiewan

Not even gonna bother.

D E N I A L.

Posted by: 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.

Posted by: BDAY

Quote:

Originally Posted by 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.

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

Posted by: 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.

Posted by: BRush

Quote:

Originally Posted by AJ Waggoner

:::::::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!

Posted by: 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.

Posted by: 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.

Posted by: 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

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.

Posted by: 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?

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.

Posted by: BRush

Quote:

Originally Posted by RADRick

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:

Quote:

Originally Posted by RADRick

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.

Posted by: RADRick

Quote:

Originally Posted by BRush

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.

Posted by: 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.

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.

Posted by: 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.

Posted by: Ol'89r

[QUOTE=just_a_rider]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]

Jeeze! Where do these guys come from?

Posted by: motometal

Quote:

Originally Posted by RADRick

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).

Posted by: dezryder

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!

Posted by: 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.

Posted by: dezryder

Quote:

Originally Posted by motometal

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.

Posted by: RADRick

Quote:

Originally Posted by motometal

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.

Quote:

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.

Quote:

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.

Quote:

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.

Quote:

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.

Posted by: Rich Rohrich

Quote:

Originally Posted by RADRick

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?

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

...or

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

Posted by: RADRick

Quote:

Originally Posted by Rich Rohrich

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

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

...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.

Posted by: Rich Rohrich

Quote:

Originally Posted by RADRick

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?

Posted by: RADRick

Quote:

Originally Posted by Rich Rohrich

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?

Yesterday you were speaking of forum fairness, today you can't wait to try and catch me in something. I didn't need Google to know what stoichemetry (not stoichiometry) is as it's used in this industry. Some won't notice the subtle difference in spelling and think you rightly caught me with my pants down. Nice try. I also don't appreciate the obvious reference to my Cuban heritage. Was that supposed to be a slur?

The main point is that with a race bike so finely tuned to achieve perfect stoichemetry, hard hot restarts are a lot more likely, particularly when noticeable changes in ambient air temp or barometric pressure occur during the race. The secondary point is that TV announcers make more of an issue about hot restarts than what is experienced by the average rider.

Did I pass your test?

Posted by: Okiewan

I need to find a rip-cord sound effect.

Posted by: Rich Rohrich

Quote:

Originally Posted by RADRick

Yesterday you were speaking of forum fairness, today you can't wait to try and catch me in something.

You took a shot at Motometal accusing him of not understanding the basis of a statement he made and I'm just following in the same line of discussion, hopefully with the same condescending tone you used.

Quote:

Originally Posted by RADRick

I didn't need Google to know what stoichemetry (not stoichiometry) is. Some won't notice the subtle difference in spelling and think you rightly caught me with my pants down. Nice try.

Quote:

Originally Posted by RADRick

As used, stoichemetry refers to the ratio of fuel to air for proper combustion in an ICE.

The correct term in combustion chemistry, is stoichiometry, most often referred to as the stoichiometric ratio, or the chemically correct ratio between air and a specific fuel. Obviously the chemically correct ratio will vary based on the fuel's make up.

Honestly I've never seen the word stoichemetry used in any automotive engineering paper or text, I've never seen it in thermal fluid engineering texts, or thermochemical enginering texts. That said, I'm sure there are tons of words I've never heard of given my lack of formal education. Common usage in engineering circles is stoichiometry.

Spelling and usage differences aside I think we can agree on the point you were trying to make with the word:

the exact amount of fuel for the available air to achieve complete combustion.

Quote:

I also don't appreciate the obvious reference to my Cuban heritage. Was that supposed to be a slur?

I didn't know you were Cuban, and never gave it a minutes thought.

I think Ricky Riccardo is funny when he says that and I say it to people all the time when they same something that I think is silly or misguided. If it offended you I can say with all sincerity that it was unintentional. Anyone who knows me or has read my posts over the years can verify that kind of crap just isn't my style.

Quote:

The main point is that with a race bike so finely tuned to achieve perfect stoichemetry, hard hot restarts are a lot more likely, particularly when changes in ambient air temp or barometric pressure occur during the race.

DING DING DING, that's where you are completely full of #@*% . (that WAS intended to offend

)

Four-stroke race engines make best power in the .82 -.87 Lambda range, or something in the neighborhood of 12-13:1 air fuel ratio. Even at part throttle and light loads (low manifold pressure) you rarely see the air fuel ratios above 13.6 or so with a carb and 13.9 is a common lean upper limit with EFI on a street/race type engine. So even plunking through the pits you are running well to the rich side of chemically correct.

Chemically correct ratios in the 14.2 -14.7 air fuel ratio range (depending on fuel makeup) , make nice numbers on an exhaust gas analyzer, and show good thermal efficiency numbers which translate into good gas mileage but you are unlikely to ever encounter stoichiometry in a properly tuned race engine. Even in your computer controlled street car you will usually only see part of the time. Usually at light loads like in highway cruising or steady state partial throttle running. The air/fuel numbers at WOT are often times as rich as 10-11:1.

I don't expect you to take my word for it, so if you'd like to see real world lambda numbers I've pulled from my race engines using data acquisition systems and O2 sensors I'll be happy to share.

Hard starting during the course of a RACE has far more to do with anxiety, bad technique due to anxiety (throttle pumping, short stabbing the kickstarter, not using the hot start lever etc), and after a crash fuel puddling in the port takes time to clear. It's not really specific to the specific output of the engine or the tuning.

Race fuels designed for high rpm four-strokes tend to have narrow range low temp distillation curves. While this is great for throttle response and power at 13,000 rpm, it makes an engine intolerant of raw fuel puddling in the intake tract from a crash, or a rider accidently pumping the throttle during a hot restart.

This is true on stock CRF250s as well as 65 horsepower big bores. All my highly tuned race engines are 1-2 kick starters hot or cold in the pits or anywhere else when you take your time and don't rush. The problem is most never take the time (and I include myself even though I certainly know better) , and they hurry to not lose a position on the track and just end up prolonging the agony.

Riders on two-strokes do the same stupid things, the difference is most 2-T engines are just more tolerant of our doofus behavior due to their basic design and lack of an accelerator pump in the carb.

Four-stroke engines even when highly modified aren't so sensitive as to be influenced by small changes in air density or temperature. If an engine DOES get the bends everytime the air temp changes 5 degrees, it's a sure bet someone screwed up the cam timing in some horrific way at TDC and totally compromised the scavening.

There is a name for engines like this S L O W . Front runners in pro races aren't likely to be saddled with half-assed designs like this. Density altitude (DA) numbers have to change fairly significantly before starting is affected, and thats ONLY if the tuning isn't changed to compensate for it. No tuner worth the name gets surprised by huge DA swings to the point that his bike won't start.

Quote:

The secondary point is that TV announcers make more of an issue about it than what is experienced by the average rider.

On that point we agree, generic TV commentators tend to be pretty clueless.

Quote:

Did I pass your test?

It's not a test and I really couldn't care less if you know the difference between a fuel's stoichiometric ratio and best power lambda ratios that are actually present in race engines.

The point is you want fair treatment and yet you go and take a shot at a member, essentially calling him a TV parrot, and then hack the guts out of a concept you clearly have little understanding of to try and prop up your wobbly point.

Make your point without the BS and no one will chime in. Float up that weak ass pseudo science BS and someone will call you out everytime. There are lots of DRN members way smarter than me, so you should be glad none of them decided to rip you a new one.

Posted by: Patman

Posted by: scatman

Posted by: RADRick

Whatever you say, Rich. For the record, I didn't "take a shot" at Motometal, I responded to his response to me. Once again, your double-standard mentality rears its ugly head. You automatically see condescencion where there is none just because it's me. He questioned my reply, I questioned his back. It was nothing more. No sinister intent, I promise.

As for my understanding of stoichemetry, it is what it is. Yes, 14.7:1 is the ideal ratio on paper for pump gas at sea level, but it is not perfect in absolute, as you pointed out. The heat generated at that ratio can cause pinging under load as well as other performance problems. In high performance circles somewhere between 12 to 13.5:1 is considered ideal. I never said that stoichemetry was the only cause of hard starting, just that the narrow jetting of a pro race bike contributes more to the problem than the wide latitude jetting most average bikes use. Had I known I needed to provide a treatise on this, I would have prepared better. Glad you filled in the gaps for readers.

I find it interesting that you didn't hesitate but minutes to jump in my **** about this, but Motometal's comments about 4Ts languished for days without comment. Particularly the one about a 4T being more prone to stalling, which wasn't even germain to my post. So much for your being an objective, impartial observer, I guess. Perhaps you can expand on why a 4T, a bike with an idle circuit in its carb, is more prone to stalling than a 2T, a bike with no such circuit? Is it the compression braking? Valvetrain resistance? Rider error?

Posted by: ellandoh

everybody is out to get you......after a while maybe a thought would occur that youre causing it.

my boss is the same way, he doesnt understand why he recieves big macs covered with salt, cold fries, and booby trapped coffee lids everywhere he goes

Posted by: RADRick

Quote:

Originally Posted by ellandoh

everybody is out to get you......after a while maybe a thought would occur that youre causing it.

my boss is the same way, he doesnt understand why he recieves big macs covered with salt, cold fries, and booby trapped coffee lids everywhere he goes

Note to self: decline any offers of a meal from Ellandoh.

Posted by: Rich Rohrich

Quote:

Originally Posted by RADRick

As for my understanding of stoichemetry, it is what it is. Yes, 14.7:1 is the ideal ratio on paper for pump gas at sea level, but it is not perfect in absolute, as you pointed out. The heat generated at that ratio can cause pinging under load as well as other performance problems. In high performance circles somewhere between 12 to 13.5:1 is considered ideal. I never said that stoichemetry was the only cause of hard starting, just that the narrow jetting of a pro race bike contributes more to the problem than the wide latitude jetting most average bikes use. Had I known I needed to provide a treatise on this, I would have prepared better. Glad you filled in the gaps for readers.

Could you be MORE of a poser out here? You clearly screwed the pooch with your half-baked nonsense theory, tried to impress us with a BIG word and now you are going to stomp your feet and hope to make ME look like an ass for calling you on it.

I've got news for you genius, I AM AN ASS, and everyone here already knows it, so you're a little late to that party.

While I may be an ass, what I'm NOT is some hump who tries to blow smoke up people's butts with weak arguments and bull**** science.

Quote:

Originally Posted by RADRick

Particularly the one about a 4T being more prone to stalling. So much for your being an objective, impartial observer, I guess.

I must have missed the part where I claimed to be objective or impartial.

Modern four-strokes with minimal flywheel mass ARE more prone to stalling than bikes were in the past. While I certainly don't agree with a lot of what Motometal says in 2T vs 4T discussions he is right on this point.

Dealing with you is clearly a waste of ASCII. I won't burn any more it wasting your time and mine responding to your posts in the future. I'm sure all will be happier that way. Say whatever you like, I no longer give a damn. If people haven't figured you out by now it's their own problem.

One more name to add to the ignore list/

As long as this thread is completely off topic now :

For anyone who still gives a damn about fuel curves and how they relate to load and rpm, here's the map from an EFI small block Dodge I'm working with. This is really early in the setup process and is just a starting point based on a similar combination from someone else but hopefully it gives you some idea what we are talking about. The air fuel numbers with a carb will often times be a bit lower across the board because carbs don't always play as nice as we would like them to, but it varies so much it's hard to have a specific rule of thumb that works all the time. I guess that's why we jet, then test then jet some more.

Posted by: Patman

Quote:

Originally Posted by ellandoh

He'll shrug it off as yet another unknower of big words having envy for his vast search engine based knowledge.

The interesting part is I've got a little twit that seems to have the same problem as your boss. I'm sure there is more than just salt being added to what all three of them eat and drink. My compliments to the chefs!

Posted by: BSWIFT

Quote:

Originally Posted by Okiewan

Contrary to popular belief, one of my favorite bikes was my 99 KX 250. I wish I still had it.

Me too! LOL!
Rich, I still don't know what you were putting in the tanks of bikes at DW01 in Casey. Did it come from a Mason Jar imported from a southern state, maybe, Hazard County, GA?

Posted by: dcal

does any one remember the original ?

Posted by: dezryder

Quote:

Originally Posted by dcal

does any one remember the original ?

The mods here seem to be a bit heavy handed at times, and often hijack or delete threads at will. But I'd better not say any more. KWIM? My bad.

Posted by: mg89

I like most of the threads with RADRick in it, they get intense. They also get interesting because the arguments/debates are on things I don't know.

Posted by: dezryder

...but hijacking and getting totally off topic seems to be at the mods discretion...and only the mods discretion. (including slams) Which is really lame IMHO. (From what I've seen here, they delete anything they deem insulting to them.)

Posted by: Okiewan

So why are your posts still here?

Posted by: dezryder

"So why are your posts still here?"
Today 11:11 PM

Was that addressed to me?

Posted by: Rhein

FYI my bike does not smoke

AND I hear 4 strokes loudly from at LEAST 1 mile away or more!

I can hear a 2 stroke after like 100 feet but it is really quiet compared and I am sure that my neighbors hate the damn 4 stroke loudness. I like the sound, just not at the volume.

Posted by: Shadowpillar

Quote:

Originally Posted by Okiewan

Late response, but I agree too, both need more or less the same maintenance. The only big diff with 4 strokes is they tend to not be as polluting or fuel hungry, and a 2-stroke has a better low-end than a 4 (depends on the engine)
My friend has a '92 Honda Z50R with a 4-stroke engine, he only periodically changes oil in it, in all the years he's had it, he has yet to replace the piston or rings. the only thing atm that needs replacing is the back tire and tube and back sprocket. He rides that thing harder than it should be ridden. he sometimes carries someone else on back (I know.. insanity, and the people he carries weigh over 200 lbs!) and yet, the rings arent shot, the piston isnt blown, and in all the years he's owned it, he has made one major engine repair, which was changing out the engine sprocket.

So I can also call bull**** on the stupid "4-strokes will explode omg omg" crap. Also, if your 4-stroke does need repairs every year, you're probably just lazy and dont change/add oil. and 2-strokes give you the incentive to fill them with oil because they will really crap out on you without that oil mixed into the fuel.

Posted by: +30

I'd be really jealous of the ponies the 4t's are pumping out , if my 2t didnt get to the first turn up front most of the time.

We should all be able to ride what we want. Thats where I kind of have an issue with the displacement rule. the 144 is a good thing, now its time for a 265 or better. Having a choice of what to buy is a good thing. Not a single 2t in a pro moto or even most amateur motos in my opinion is a bad thing. The manufacturers are giving up, you cant replace 200cc's with revised porting and bold new graphics. The displacement rule book has killed the 2 stroke.

Posted by: +30

I'd be really jealous of the ponies the 4t's are pumping out , if my 2t didnt get to the first turn up front most of the time.

We should all be able to ride what we want. Thats where I kind of have an issue with the displacement rule. the 144 is a good thing, now its time for a 265 or better. Having a choice of what to buy is a good thing. Not a single 2t in a pro moto or even most amateur motos in my opinion is a bad thing. The manufacturers are giving up, you cant make up a 200cc disadvantage with revised porting and bold new graphics. The displacement rule book has killed the 2 stroke.

Posted by: RS1441

Quote:

Originally Posted by Rhein

FYI my bike does not smoke

AND I hear 4 strokes loudly from at LEAST 1 mile away or more!

I can hear a 2 stroke after like 100 feet but it is really quiet compared and I am sure that my neighbors hate the damn 4 stroke loudness. I like the sound, just not at the volume.

my friend lives in a valley he has a 125 and i have a 250 4-t and sure mine close does sound louder and drowns out his 125 but when he goes to the very far end of his fields on his bike the high pitch screetch travels alot further then when he uses my bike with the lower roar. the 2 stroke sound travels alot worse in my opinion i am sure.

Posted by: Rhein

Quote:

Originally Posted by RS1441

I live in a valley too, I have mountains right up next to me. I can hear the 4 strokes and not the 2 at a similar distance. It is a scientific fact that a 4 stroke sound resonates at a frequency which travels a LOT farther. You can't argue with that.

Why in the hell is there ride stealth crap everywhere? 4 strokes are louder than hell.

Posted by: Rich Rohrich

Quote:

Originally Posted by Rhein

It is a scientific fact that a 4 stroke sound resonates at a frequency which travels a LOT farther. You can't argue with that.

Care to share the source of that science with us?

Posted by: RS1441

i still say the high pitch will travel further but meh maybe it doesn't but i can hear the high scream of the 125 at further distances also about the ride stealth i thought that was because 2 strokes make a crap load of noise with pipes and crap but 4 strokes aren't exactly quiet

Posted by: BSWIFT

A freshly packed silencer will help both 4t and 2t sound volume. Simple solution to the debate in my opinion.

Posted by: ellandoh

i tell you one thing for sure , i knew of no personal tracks around my house til they switched to 4 strokes, now i track em (by the noise) and make em let me ride. i tracked one down last fall after the leaves fell and the air was crisp that is 4miles as a crow flies from my house. never even heard any bikes when they were 2 strokes

Posted by: kx125412

From my experiance it depends on what bike your riding. Say if you had a crf 100, those things you can barely hear. Compare that to an 85 2 stroke and the 85 will be much louder. But on the bigger bikes like 125 2 strokes compared to a 250f, I think the 250 is wayyy louder and you can hear the sound resonate through the woods more-so than the 125. Same thing with 250 2s and 450s. I was out riding the other day with my friend and there was a big group came in with 2s of all sizes including a couple 500s and there was 2 people on a kx 250f and a crf450. The 4 strokes completly drowned out everything. They all left at the same time and you could only hear the 4 strokes not a whisper from the 2s. All over the mountain just the brrrr of the 4 strokes.

Posted by: cranky

From owning and working on numerous bikes over the years (YZ125s,YZ250s,YZ250fs and an 06 RMZ450). We are going back to 2-strokes at the end of the year (most likely YZ250).I can only speak from my personal exp. and for the shops that I deal with but here in AZ. the 2-stroke is a lot cheaper to maintain/rebuild. If the AMA changes their class rules like they are talking about, it will help and even if they don't,we are switching back anyway. The 4-srokes have cost me a lot more than any of our 2-stokes did.

Posted by: +30

plus the new ama rules put the 250cc 4t in with the 250cc 2t. It looks like open bikes will still be ruled by 4t's but the 250 class I would think would be mainly 2t.Very interesting to see what happens on the sales floor

Posted by: wardy

Rich,

the science is that I can proove that to you any day we are open at FVOR. Its fact, can it be proven, i bet it can.

can he or I proove it, "scienctifically"* who knows, but any saturday or sunday we can drive down the street and you can tell me what you hear.

wardy

on the sales floor they may be a "slight" increase in dusting, you know dusting off the two stroke so they can sell it, I am sure the dealers won't mind the extra room?
but any increase in 250cc 2 stroke sales will likely be minimal at best.

Posted by: 04kdx200

The words: sound waves, directional, and omni-directional come to mind.....

I don't know why.... make it stop!!!

Posted by: Rubey

Quote:

Originally Posted by Rich Rohrich

Care to share the source of that science with us?

Given similar power levels, lower frequency sound waves travel much further and are more difficult to block. That's the reason you can hear someones subwoofers (low frequency) for such long distances. Higher frequency sound waves are more easily scattered and absorbed by not only the silencer, but the immediate surroundings as well.

As for the sources... It's basic physics that can be found in any 1st year engineering physics textbook. You can probably find a simplified explination in a high school "conceptual" physics textbook as well.

Aint science and engineering a wonderful thing.

Posted by: Captain_shaft

I'm a two stroker, but my best friend just bought a four stroke, true, a good amount more expensive, to the best of my knowledge, fourstrokes are much easier to learn on, (due to the absence of a kick-in the pants power-band) and then later, if you want to go to a two stroke, its much easier than going from two stroke to four stroke

Posted by: endofsilence808

lol 4 years between ring changes...I love the internet. the internet should be called "the squidernet"...as far as the whole 2stoke 4stroke debate. i.m.o. only about 5-10% of the general public can ride the new moto bikes to the limit anyway, so it just like going to a bar when deciding. just order what you like. I prefer two strokes cause thats what I know and to an old school guy, the fours just remind me of a john deer. you shouldnt worry about banning unless in cali, just buy a quiet silencer. but the two stroke maintence is way easier for a rookie and 150 for a two stroke silencer compared to 300-400 sliencer for a four. That is about the % of dollars in maintance you will spend on the two. however 4 strokes might be a little easier to ride for a new guy. I know one thing my yz250 can still pull holeshots..so no worries here. plus now my old lady know exactly where i am on the track.

Posted by: CRazy250

well 4 strokes need twice the displacement to keep up with a 2 stroke. its a simple and faster.

Posted by: OldTimer

Quote:

Originally Posted by FruDaddy

... Then there is the fact that the thumpers are harder to start when hot...(hot start lever required)....

Quote:

Originally Posted by Okiewan

LOL.
My point is made.
...One week, no starting. Blip the throttle 2x, pull the choke ...2 kicks, it's running. I'm sure your 2-T starts much easier tho.

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

I've only ridden a modern 4T about a half mile,
but I've spent a lot of time helping my riding buddies kick their 4T's!

Posted by: MX86

i had 20 hours seat time on a thumper. 16 on a yz450f and 4 on a thumper sled. now i dunno about you guys but why the hell can't the motocross bikes sound like the RX-1 or phazer, or R1 thumpers? in fact i won't even call them by that name. there is no thump to the engines. it's a deep murmur.. is there that big of a difference? they took the motor for the phazer basically out of the 450F and modifyed it a little for colder weather... i don't here a thump out of it.... i hear a sweet sounding low waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaamp really neat in my opinion. so why the loud thump for motocross?

any mechanics care to shed some light here would be greatly aprreciated. i don't understand exhaust systems on a 4 stroke. like why you have a little header pipe into this monstrosity you call a silencer. wnd why do they call it a silencer? normally it makes it louder.. we are part of a contradicting sport i just realized that

Posted by: motosteve

Quote:

Originally Posted by MX86

i had 20 hours seat time on a thumper. 16 on a yz450f and 4 on a thumper sled. now i dunno about you guys but why the hell can't the motocross bikes sound like the RX-1 or phazer, or R1 thumpers? in fact i won't even call them by that name. there is no thump to the engines. it's a deep murmur.. is there that big of a difference? they took the motor for the phazer basically out of the 450F and modifyed it a little for colder weather... i don't here a thump out of it.... i hear a sweet sounding low waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaamp really neat in my opinion. so why the loud thump for motocross?

any mechanics care to shed some light here would be greatly aprreciated. i don't understand exhaust systems on a 4 stroke. like why you have a little header pipe into this monstrosity you call a silencer. wnd why do they call it a silencer? normally it makes it louder.. we are part of a contradicting sport i just realized that

They all have more cylinders.....hence more combustion cycles per revolution.

Posted by: ThumperCJH

i have a 2002 4-t ttr125 and haven't replaced anything on the motor!

not even had to adjust the valves yet

so all you land haters out there who think 2 smokes all the way to go why don't you just either one move to canida 2 die or 3 buy a 4 stroke

Posted by: IndyMX

Quote:

Originally Posted by ThumperCJH

i have a 2002 4-t ttr125 and haven't replaced anything on the motor!

not even had to adjust the valves yet

so all you land haters out there who think 2 smokes all the way to go why don't you just either one move to canida 2 die or 3 buy a 4 stroke

Dude.. it's Canada not canida..

Posted by: FruDaddy

And the TTR125s aren't even in the equation; my son outruns them on his KX65 all the time.

Posted by: DougRoost

Quote:

Originally Posted by MX86

Yep, the 4 stroke dirtbikes sound like loud farts to me!

I switched back to a 2 stroke after ~2 years on a 4 stroke. I don't think it's easier to learn on a 4 stroke...probably easier to learn to ride right in the first place, using both brakes, etc. on a 2 stroke. But to each his own, as long as we have choices.

Doug

Posted by: DougRoost

Quote:

Originally Posted by ThumperCJH

i have a 2002 4-t ttr125 and haven't replaced anything on the motor!

not even had to adjust the valves yet

so all you land haters out there who think 2 smokes all the way to go why don't you just either one move to canida 2 die or 3 buy a 4 stroke

That's a scooter motor in a playbike, not the racing 4 strokes being discussed in this thread.

Doug

Posted by: ThumperCJH

your right it is

Posted by: john stu

Quote:

Originally Posted by 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.

valves valves valves i dont need no stinking valves.....unless its a reed valve

Posted by: Cory326

I like to look at this whole topic like this... Buy what you wanna ride and forget about the rest. 2 stroke or four, who really cares? Worring about all this stuff is silly...they're machines, they ARE going to break eventually, thats why they make new ones every day. Basically, being able to ride is more important than WHAT you ride.

Posted by: Matt 193

2 strokes are all fun 4strokes are all work no play if you only want to win without much fun buy a 4 stroke not that they arent fun its just 2 strokes are funner

Posted by: 02yz426f

All bikes are fun to ride, even if the engine is big or small, 2 stroke or 4 stroke. Enough whining

Posted by: alligatorbling

i can remember the first time i rode a dirtbike, it was so awesome... well not the very first ride... i made it 7 feet and tipped over lol, i was just a small kid, maybe 8 years old, im not sure. anyways, after i got cleaned off i got back on and got some more practace, and was feeling great and doing fine on it, having more fun that i had ever imagend. i remember this very clearly, and i also remember having no idea what 2 or 4 stroke was. it turend out it was a 2stroke, kd80, however it made no diff... bikes are about fun. dont let tech get in the way =)

Posted by: 200cr125rippaah

i actually have 3 bikes one is a smoker and the other 2 are thumpers the 150f im really unsatisfied with stock but the 07 150r ( all honda of course) is great i love the powerband how ever it is very loud. we all race on ice and my cr 125 with the procicuit engine has gone 3 years withj out top end changes ( seals gaskets nothing ) and it was hauling

Posted by: cantrell24x

Wow that's a long read.

I am not sure I understand how offroad motorcycle R&D provides any real world support for the big four.
Honda maybe but I would think they get more than enough from auto racing or road racing bikes, and that technology would be easily transferred.

I think Yamaha has developed a car engine or three.

I haven't kept up with the times but aren't boating engines and yard equipment engines also switching to 4t?

This would lead me to believe that environmental issues are the big reason for the switch.

I think the big four made a proactive decision and now they need to get their money back out of the 4t bikes.

If it is true that 2t are not the polluters they are claimed to be it will not be too long before they come back.

Unless the manufacturers have realized it is easier to make money by financing 2 bikes than by selling three bikes. The o/n interest rate in Japan is nearly zero. I have not proven it but I suspect this fact has a significant impact on the new bikes we ride.

Posted by: lynch racing

Quote:

Originally Posted by just_a_rider

. You can get a valve job around here for about 30 to 40 bucks. .

You can`t even buy 1 high quality valve for 30 bucks!!

Posted by: lynch racing

Quote:

Originally Posted by Rhein

I live in a valley on top of a mountain and 4 strokes are the main culprit of closures, they made a better mousetrap that will make all mousetraps end up sitting in garages with no place to trap mice! If a 98 db limit is not put in effect and enforced no one will be louder than hell. 2T`s can make the limit, 4T`s will have to struggle....
I agree with Rhein

I have tried to get the promoters to support a 2T only race program in the USA in order to preserve the sport and make it affordable to the masses. 2T only races are growing in attendance in Europe and can support a track profitwise plus keep the noise closure issue at bay, A 2T only profit is much higher than a track closed profit.

Posted by: Zipp0

this is totally the wrong approach. The sprint car races near me are 100 times louder than any motorcycle could ever hope to be, and nobody is shutting them down.

Posted by: Moparman1539

Quote:

Originally Posted by Zipp0

this is totally the wrong approach. The sprint car races near me are 100 times louder than any motorcycle could ever hope to be, and nobody is shutting them down.

Yeah in the summer when i go to my dads house. They race till like midnight. And its really loud. Makes the windows rattle, and you cant even see the place from my dads house....

Posted by: trailrider822

i always love my two strokes, and will keep them running on my property LONNNNNNNNNNNG after any bans on any motorcycles go into effect at any point in time. I am currently doing a lot of parts shopping for two stroke parts, and am collecting empty boxes to store them in with labels. I will be doing parts shopping every month for the rest of my life, i am sure. lol. So as far as tech changes go over the years, i am not gonna worry bout it.

Posted by: Mickmoto

Just my 2 cents but I rode a 2001 CR250 2 stroke for some time, just got my new 07 CRF450x and I love it. I noticed more of a handling thing then a power thing, obviously the newer bike rode much nicer, but that’s to be expected with how new it is, so I couldn’t really tell you if an 07 2 stroke handle like the 4. The 2stroke had massive power that came at me like a wave in the ocean where I find the 4stroke is more evenly displaced, enabling me to ride much more aggressively with much less rider fatigue. I live in California, and I do see a lot more 4 strokes at the riding areas but I have never gone a weekend without seeing and riding a 2stroke. Great info at this site,awesome thanks

Mick

Posted by: AnnihilateYZ

I've got a solution....Anarchy!!!

Posted by: snowboardin522

KX250! love My 2-T. Gotta love that power band!

Posted by: Rhein

Quote:

Originally Posted by cujet

Also, 4 stroke noise levels are generally higher and it is my opinion that the 4 stroke noise carries further. Not a good thing when riding at the local "pit".

Then there is that wonderful, incomparable feel of a super light weight, powerful 2 stroke

but we won't go there in this discussion.

Chris

Your opinion is based on facts. The 4 stroke engine produces a lower frequency noise than the 2t. Lower frequency sounds usually travel much farther (think Elephants). On top of that, 4Ts are usually a lot louder. I know from experience when I am out and see a 4t and a 2t pacing each other I can't even hear the 2t but you can hear that 4t fartin away.

My friend has a brand new CRF450R that he blew up, needs a whole new top end, he priced it out at the dealer and can't afford it, it was into the $1,000s. Now if you can afford that, more power to you, he regrets not having his YZ250 anymore. He is making payments on a bike that sits. If you can afford the 4t great, if you can't then the 2t is for you. We need choices.

Posted by: Jeromeo

2 strokes are better anyways

Posted by: Jeromeo

I love stirring the pot

Posted by: RubenCR

Quote:

Originally Posted by XRpredator

Deep down I have a seething hatred for the ring-ding, smoke belching 2 strokes.

and it don't matter how many words Perry Mason puts in a post, 2-strokes still suck.

Why's that becasue you can't ride them

, there should be no reason for you to hate them except for your own personal opinion give me a decent reason and i'll consider what your saying isn't !BS!

Posted by: XRpredator

Quote:

Originally Posted by RubenCR

. . . there should be no reason for you to hate them except for your own personal opinion give me a decent reason and i'll consider what your saying isn't !BS!

rejetting when a cloud passes over
mixing gas
twitchy lightswitch power characteristics
wheelspin
constant rebuilds
Two-stroke luddites who just can't let go

There, now you have six.

Posted by: DougRoost

Nice job, Pred...you just reaffirmed what RubenCR said.

And to throw in the lame mixing gas thing again. Most of you racing 4 stroke guys buy race gas anyway, for goodness sake.

Posted by: DougRoost

After watching Epic ride where they ride quads at Glamis, my take is this 4 stroke thing is not just about Harley Davidson's eventual return to offroad coupled with the Japanese manufacturers wanting to reuse all their streetbike R&D into dirtbikes. It's more and more about the using the same engine R&D from their quads into the every-day-a-little-less-important offroad motorcycle segment, without regard to the actual application. 10-20 lbs extra in a quad, so what? That same weight gain paired with less turning ability in a motorcycle is sad for woods riders.

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Whats the point buying a two stroke anymore?

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