Two Stroke vs. Four Stroke – Let the debate begin

Whenever the debate between two strokes and four strokes begins, proponents on both sides bring up various reasons to defend their position.

In many cases, real facts with proof are ignored, misused or misunderstood. At times, the arguments boil down to hearsay. Some of it  blatant lies.

This is has created a divide between the 2T’s, the 4T’s and their supporters. Each side becomes defensive and many times useful discussions turn bad quickly.

This is bad for our beloved sport of motocross.

Every one has an opinion and they are entitled to their opinion. But at times that opinion may not be based on facts.

Let’s look at some of the most commonly stated reasons four stroke racers and two stroke racers debate. I will not go into detail on any of them right now, but just get them out on the table. We will examine each in depth over the following weeks and months.

Yamaha YZF engine cutaway.

Yamaha YZF engine cutaway.

• Four Stroke technology has surpassed Two Stroke technology. Many four stroke supporters say that the two stroke has had it’s day and it’s now the four stroke generation.

• The EPA (Environmental Protection Agency, USA) has a ban planned for all Two Strokes, so the manufacturers had to switch to four strokes, beginning in 2010.  Since California has the strictest environmental laws and all four manufacturers have their US headquarters located there, this ruling would have a huge impact.

• The four stroke revolution has brought about higher sound levels that threaten to destroy motocross. While the sound of a two stroke may be louder when you are right next to it, as compared to a four stroke, that sound does not carry near as far. The booming four strokes can be heard for literally miles away. This has lead to riding areas being shut down and anger among neighbors of riding areas.

• The FIM / AMA rule change allowing a displacement disparity between 2T and 4T race machines. This was unprecedented in all of racing. It was not just that they allowed an advantage, they allowed the four stroke to be double the displacement of a two stroke.

TM Racing 125cc engine.

TM Racing 125cc engine.

• The four stroke bike is easier to ride fast and they inspire confidence. Jumps that would have been impossible to perform on a two stroke are easy on a four stroke. But is this a mixed blessing? Could this be the catalyst that has lead to racers getting injured, because they had taken a shortcut in their racing education?

• The cost of racing has increased dramatically.  Just the exhaust system for a 4T costs at least double if not triple the cost of a 2T system.

• The upkeep, rebuilding and maintenance costs are much higher for the 4T than the 2T.

• When is a DNF not really a DNF? In professional racing, there is now a phenomenon when racers fall or stall and they are unable to restart their four strokes. The result – lost races and National Championships because a highly paid professional racer can not restart his race machine.

These issues are just some of the challenges that our sport is facing. We are not only in danger of  losing the two stroke, but the future of motocross could be in jeopardy.

Over the next few weeks/months I will explore each of these issues in depth, supported by facts from relevant sources. It is time to leave the emotion-based opinions behind and work together to build our sport up to new heights.

As always, I am interested to hear what you have to say on this subject. Please feel free to leave a comment below.

Boxing photograph entitled “One on One” by ElMarto – Flickr
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38 thoughts on “Two Stroke vs. Four Stroke – Let the debate begin

  1. Since the introduction of modern Four stroke, the sport lost his “sex appeal” . There is no substance. I wish to see a modern 2 stroke hit the market with EFI and updated frame, look and same displacement as the four joke.I’ll be buying 2 of these! I’ll be more happy than Obama when he got elected!I love my sport to death, just sad to see it manipulated by racing organizations,manufacturers and the medias because WE riders should have the last word on any changes concerning it.

  2. I’ll start with your first point, that 4T technology has surpassed 2T technology: even if true, so what? That’s like saying that the violin has seen its day and it’s time to replace it with the electric guitar. All that matters is getting across the finishing line first, or having a good time riding the bike. Who cares what the relative level of technology is? Truly a specious argument.

  3. Thanks for the comments!!

    Hey warburtonm, I agree with you 100%!

    To clarify, the list I made was collected from my experience of reading message board arguments between 2T and 4T’s.

    To me the non-nonsensical part of this is the people that say that 4T technology has surpassed the two stroke, why do they leave out the displacement disparity? How can a technology be better when it has to be twice as big?

    It does not compute!!

    Stay tuned for further articles that will address each of these “conversation” starters in greater detail.

  4. 2 strokes rock.period. 4 joke technology might be advancing, but it doesn’t make them any better or more reliable(actualy less). I would like to see bubba hop on a yz250 and kill the 450’s

  5. What I would like to see is a less emotional response to the 2 stroke (2T)/4 stroke (4T) debate and more substance. For instance, technology wise, the 4T has developed extensibly since the FIM/AMA established the double displacement rule, while the 2T has had very little changes. If you were to compare an EPA legal 2T to an equal displacement EPA legal 4T, how would they match up?

    In the 1970’s, when all cars had to adopt strick EPA codes, we pulled the smog devices off the cars to make more power. However, today we can make more HP from smaller engines and still be environmentally legal. I foresee the same with motorcycles. If the FIM/AMA were to change the rules and make all racing machines meet a strict standard for emmissions and noise – and enforce that standard at the events, it would be the same for everyone and the aftermarket would eventually find the lost HP.

    Of course, we would all “strip that junk off” our non-race bikes for awhile, but then we wouldn’t be able to race our stripped bikes at FIM/AMA events and eventually we, the masses, would adopt the cleaner motorcycles.

    Make no mistake, the manufacturers jumped on the 4T bandwagon because governments and the FIM/AMA put pressure on them to do so. Those organizations are the only ones who can save the 2T.

  6. My big problem with 4 strokes is the displacement advantage. Noone would ride a 4 stroke if they had to race against 2 strokes of equal displacement. I don’t find it easier to go as fast on a new CRF450 as I do on my 87′ CR500. Sure the suspension is better on the 450, but it’s also slower and doesn’t turn much better and the lap times don’t lie. Throw that engine in a modern frame and it’s no contest. Case in point a buddy just finished his aluminum framed 500. It’s an 04 chassis. He took it to the track and let everyone ride it, including a local pro. The kid had never been on a 500. He came back in and said his 450 didn’t have anything for it. That kid is a 4 stroke fanatic but got a dose of reality that day. That’s all with a stock carburated dinosaur engine and an out of date chassis with stock suspension. We don’t even have to get into engine rebuilding costs.

  7. 2 Stroke technology has been at a stand still for many years. KTM, GasGas, TM, Husky and a few others are trying to improve the technology. Yamaha still mfg smokers, but pushes the 4 stroke. Suzuki is getting back into the 2 stroke, but not in the US. The problem is the all R&D had been put into the thumpers. The real question is, What are the Japanese MFG’s afraid of?… They are afraid that since they’ve dumped so much into the R&D of thumpers, that a smoker with yesterday’s technology will….. “smoke” their thumpers. (Pun intended).
    Please do away with the class limits, let the classes be based on CC’s. Thumpers have evolved to where they do not need the protection of double the displacement, Since Honda and Kawi have both dumped development of the smokers, only Yamaha, and Suzuki (outside of the US), still mfg smokers. KTM, GASGAS and a few others are still improving on the smoker.

    In today’s jump fest SX tracks let the rider choose what he wants to
    ride. I can see in SX that depending on the track, a “professional”
    racer switching between a 2 and a 4 stroke. Example Anaheim… Pretty open track, a smoker would have done well. Houston, really tight, a thumper may have been the stead of choice. Now in MX, that’s a different animal. I see more smokers than thumpers at the starting line. Off road racing, 2 strokes are still the bike of choice for many a rider, but that choice is being taken away as we are stuck with less and less choices. Plus an amateur cannot afford to competitively race a thumper. It just too expensive to rebuild, or repair after a weekend race.

    Its just a sad state of affairs that the MFG’s are the one who decide the fate of the 2 stroke machines, especially since they know an out dated 2 stroke 250 will thump a modern thumper.

  8. I can tell you what the manufacturers are afraid of. They are afraid they will have their market closed because of emmisions. As stated elsewhere, a modern 2 stroke motorcycle is the particle emission equivellent of 10 cars. Thumpers are cleaner (still not clean as a car) so to prevent government regulation, they have gone to the dark side.

    I would be very interested in comparing like machines. Same cc cylinders, same particle emmisions, same noise level. I believe the thumper would win (that is until R&D was put into the 2 stroke).

  9. Thought this might make an interesting post –

    I live in England and I’ve always loved 2 stroke motocross bikes. I went out to Thailand a few years ago and had a blast with a mate hiring some 2 stroke 250cc Honda and Kawasaki KDX’s, we were in paradise in the middle of a tropical island in the summer racing around together on these bikes with huge powerbands – it was amazing.

    When I got back to England I thought it was all over when I found out about a law that means we can register any off road motorbike for on road use, fully road legal – it’s called ‘Enduro Exemption’ and means so long as it’s an off road machine we can by-pass the usual controls associated with registering normal motorbikes and cars.

    I found out about it by chance after I saw a KX250 2 stroke for sale fully road registered on ebay, I looked into it and found it was legit so I bought the bike and then since that time I’ve bought my brother a YZ 250 and we registered it ourselves, it only costs £50 and a few forms! Insurance is about £125 a year and road tax £35 a year thats all it takes.

    The best thing about it is we don’t have to modify the bikes to get them road legal – all we had to do was put a mini license plate on the rear mudguard and a battery powered horn. Both our bikes are straight off the race-track, propper motocross spec, no lights or anything (we have to stick out arms out to ‘indicate’ lol..) I added a speedo so I know who fast I’m going in case we go past a speed camera but thats pretty much it! I still have my knobblys on!!

    I know some people say ‘why put an off road bike on the road its stupid’ but I love the 2 stroke 250’s. I know dirt tracks are fun but personally I dont want to have to only be able ro ride at dirt tracks, apart from the fact there are not many around here and its quite restrictve in terms of having to go round the same piece of land over and over and I want to keep my bike in perfect condition..

    So now me and my bro can get on our bikes whenever we want and ride where ever we want, no limits at all. It’s absolutely amazing – everywhere we ride we turn heads, people just don’t expect to see 2 guys on pure MX 2-stroke 250cc machines howling past them on the road.

    At the weekends we can travel all over the place on our bikes – we even have to mix our gas at the the petrol stations while we fill up – hitting the power band at full pelt on the high street always gets people whoooping at us as we go past!!

    I think England may well be one of the only countrys in the world where you can do this & it’s the most amazing thing – I love my bikes!!!

    It’s such a shame and unfair that 2 strokes are dissapearing from the tracks and the showrooms, they are the ultimate machine, after finding this site I’d like to look into getting one of the new 500cc ones you featured.

    We have got to keep up the pressure to bring them back!

  10. if you think 4T technology has surpassed 2T technology, you might want to check out the following website:
    click on the “E-TEC and 4-TEC ENGINES” tab
    click the “Find Out More>” button.
    click 600 H.O. E-TEC and check out the dozen or so engine animation videos.

    You may never look at a 2 stroke technology the same again ;-)


  11. The twincam four valve four stroke engine was invented in Spain in the 1920’s.Walter Kaaden invented the two stroke expansion chambered exhaust in the 1960’s.The progression of technolgy is relentless and the advancements we have seen in four stroke technology were artificially induced through enviromental legislation.I personally think that the advantages of a two cycle engine,simplicity,high power to weight ratio and ease of manufacture (costs included)will someday allow it to dominate again.The almighty dollar rules and once enviromentaly two strokes can be produced in an economical fashion – they’ll be back.

  12. On with the 4t vs. 2t war. I am not a pro motocrosser, not even close. However I went to the supercross races last year in San Diego. As I wondered though the pitts and marveling at all the big factory support teams and their hugh bugets. They are there to win races, so they can sell bikes and parts. I went a little further, wayyy… in the back of the pitts. I came across a couple of privteers, barely surving and living out of their van traveling and racing the supercross seriors riding of course 4t. My question is pretty simple. If these guys are pro riders, why do they choose to ride 4t and not the 2t. These guys were really stuggling (econmicly) to be there. And they were no dout suggling to compete in the supercross series and the price of mant
    aning a costly 4t that need expenive top ends. Why arn’t these guys riding 2t? There must be some kind of advantage to the 4t (and I am not talking displacement). There must be something there from a pro riders perspective that gives the 4t and advantage? So please can someone that KNOWS, that really KNOWS help me with this delma

  13. I personally think the reason for this is because all the top end riders you saw at the front of the pits sell their second hand used top ends for nearly 1/3 the price if not lower. I built a yamaha YZ250F strictly on parts (clutches, top ends, pistons, spark plugs, cases, tires, rims, etc) purchased second hand from the back of pro riders trailers and from their pit sections. I had to buy the odd thing like clutch cables and stuff like that but nothing major. The overall cost to have this bike built from the ground up and complete to factory riders specs was just under $8,000… thats cheaper than a brand new YZ250F I might mind you it took me just over a year to complete the build but boy it was sure worth it and definitely cheap. The only thing I wish I could buy second hand is Race Gas lol

  14. 2 Strokes actually take skill to ride good, anyone can ride a four stroke. No 4 stroke will ever compete with the torque and power that a 2 stroke can deliver. Put a life long 4 stroke rider on a 2 stroke and i bet they wont be able to handle it. Only reason 2 strokes are fading away is because this whole global warming farse has the country brain washed and the big sponsors have to follow along with it and sink all their money into four stroke technology so they dont look bad to the public. So go buy a 2 stroke and piss off all these hippy liberals and smoke the four strokes and let them know they will not take these away from us.

  15. the four strokes are the better all around machine they have bottom end mid range and top end and four strokes dominate the races. since they have power all around you’re not relying on powerband to save the day. 2 strokes may feel like they have tons of mid and top end but that just stands out because they have absolutely no bottom end so thats why their mid range and top end stands out so much. no matter where you are in your rpms on your four stroke the power is always there. the only thing that 2 strokes have is better handleing. but with a fourstroke they’ll go forever as long as you change your oil regularly a four stroke will go forever. with a 2 stroke they will all eventually be due for a rebuild. if you mix the gas just slightly too lean say goodbye to your engine. with a fourstroke just run the highest octane gas you can get and everything is fine. theres a reason why honda, kawasaki and suzuki stopped making 2 strokes, 4 strokes just out perform them.

  16. 2T Rules every class up to the stupid “point & shoot” bikes from japan, 2T Beats 4T on scooters, it beats them on 125’s, it beats them on 250’s, the 500 2 strokes are absolutely untouchable and i do recall there being a kawasaki 700cc 2 stroke, that is some serious stuff.
    Okay your modern R1 Or Blade will beat most things, but its what your into.
    However, sticking to the point of motocross, its time for the 2T to make its re-entrance on the track, expansion chanmbers the size of the hulks bicep, (in the 500cc case) more torque than the vans that take them to the tracks, so much easier, okay you might get a fouled sparkplug every once in a while, but for that burst of powerband and amazing noise, its so worth it.

  17. im so sick and tired of everyone being against the 2 stroke. everyone that is a serious rider is for 2 strokes and the people that dont ride hate them. and they are the ones that get to throw them out? every single forum i read 98 percent of the people are as peeved as me about all of this. bring the 2 stroke back! i dont know why the big manufacturers are ignoring us.

  18. hi, i’ve own a mito 125 2 strokes and it is much more fun than a 4 strokers.
    Lightweight, fast and loud. but the parts are really2 expensive here in malaysia =(

  19. wtf. jumps that would have been impossible on a two stroke are easily done on a four stroke? hmmm i guess thats why free stylers use two strokes cuz theyre not faster or lighter or anything like that.

  20. ridered….you remind me of a abortion servivor…the first thing thats wrong with your little statement is what you said about 2t having more torque than 4t… i have two little 2 horsepower scooters and i have to push my 2t scooter up a hill…BUT the 4t may be heavier but it can actualy cary me up a hill….and on the power factor of a 2t just cause your tires are spinning and you are going fast dosent mean you have a shit load of power, it just means that you have more high end power….on a 4t you can start at the bottom of a steep ass hill and get up it no prob(on a 2t however you have to get a running start) and 4t technolagy completly surpasses the tech. of a 2t…and i will give it about 2-3 years and 4ts will be as light as 2ts

  21. i own 3 bikes 1987 can am ASE200, 2011 kawasaki KX250,2007 honda Cr250r
    all 2 stroke and i rode my friends 2005 CR450 and it was nothing compared to my 2 strokes. 2t’s are way better then 4t’s not biased or anything it just my opinion. my 200 can clear the table in 3rd the 450 has to clear it in 4th

  22. You can tune a 2 stroke any way you want. I have an old kawasaki 350 2 stroke that has more torque, more sheer ass than any modern 4 stroke. I rode a friends yzf450, and yes, it was quick but after hearing all about how “crazy” the new 4 strokes were I had psyched myself up to be scared and amazed. It was pretty flat. The power I mean. Too easy, no rush. I got off the 450, and I was like, that was it? My 75 KX400 scares me FAR more.

    I am a vintage guy so and I have always thought that having lots of plush progressive suspension made it TOO easy to ride fast and jump high, its soooo forgiving. I see dumb mistakes made by modern riders at the local tracks that would have hurt someone bad in the old days, but the suspension just eats it up. The 4 stroke engines of today just add to this. It takes alot of the skill away from the game.

    NOTHING and I mean NOTHING can match the rush of when a big 2 stroke comes on the power. Not to mention that the SOUND of a modern 4 stroke is obnoxious and is KILLING the sport. Read; track closings, riding area closings, etc.

  23. otherwise.. 2 stroke is better than 4 joke, because, the maintenance of 4 stroke are higher than 2 stroke… i like 2 STROKES! because they have power.. and they said that 2 stroke are smokers.. but now, See the YAMAHA YZ125 or 250 2 STROKES… they dont have smokes.. thats the technology for now

  24. i rode 4 strokes for 6 yrs,got bored with them and after a lay off due to injury decided to buy a yz250.i have no interest in ever getting back on a 4 stroke! i love my smoker it makes me smile every time i ride it,i spent £600 on having the engine bored to 265cc and tuned to give it a nice smooth delivery,got a full pro circuit exhaust which cost £280 brand new,this bike is just awesome to ride,and the sound is sweeeet! sure i spent a bit of money on it but thats just because i could,and the money it cost to have all that work done is still cheaper than you could buy an exhaust for a 4 takes more skill to ride a 2 stroke well,and for me is much more satisfying.this weekends my first back on the bike for 12 months and i can’t wait to feel the 2 stroke power again.

  25. love the 4 stroke junk lots more parts to charge you for just got 1500 to change and clean up a 25 4 stroke and install a head gasket every thing going back to 2 stroke with fuel injection cleaner than a fen 4 stroke your 4 stroke will soon be obsolete get rid of this pc correct mf b/4 you lose your arsh with it

  26. why are only the4 stroke haters coming on here???do u guys wanna prove 2 strokes are better that bad??? YOUR RUINING THE SPORT! all that matters is having fun.. i love 2 stroke and 4’s. but 2 strokes get to much credit…2 strokes are going out cause people dont buy them! epa is half of it. people dont buy them because they cost 2 much to maintain and theve reached theyre limit. now 4 strokes are going up.

  27. what are u talking about more maintainance i own 2 and 4t’s my 4t has oil changes oil filter valves than the things like the 2t wich is air filter and a wash after every ride, and + 2 strokes are lighter better sound,handleing,fun,power(cc wise), and simpler

  28. burnt gas comes out the exuast port in 4 strokes every two cranks emits a spark when it sparks in the cylinder with burnt gases it wears out the spark plug faster. plus 2 strokes have no valves which makes them lighter

  29. one wonders what could be done to improve 2t technology to be more environmentally friendly. No doubt that if the same money that has been spent on 4t’s was spent on improving 2t’s things would be drastically different. To me, 2t’s technology not only makes more sense, but is better in almost every way besides emissions. Now, very recently 4t’s have been outpreforming 2t’s because of vastly superior technological advances. Well what if 2t’s had the same opprotunity to be modernized? Simpler design, cheaper repairs, cheaper parts, easier repairs, more power for less displacement, lighter, cooler sounding (opinion of course) and the list could honestly go on.

  30. You guys make me laugh. Here’s a true story. I have an old 1982 RM80 which I bought years ago. In 2009 a mate of mine got a brand new CRF230. I weigh 90 odd kilos and guess what? On an 1982 80cc two stroke I demolished the shit out of his brand new CRF230. Four strokes are amazing… at getting raped. The argument can go on for ever, at the end of the day a same displacement 2 stroke will ALWAYS beat a same displacement 4 stroke.

  31. My parents gave to me the most awesome x-mas gift I ever received in 1980. I woke x-mas morning to find a brand new Honda CR80R all shinny and new beside our tree. From the first moment I started the bike and smelled that wonderful 2-stroke mix I was hooked. I really don’t care if 4 strokes save penguins I like what I like. I currently ride a Polaris Sport 400 2 STROKE and will always ride a 2 STROKE. My Stihl chainsaws, leaf blowers, weed eaters are all 2 STROKE and they always will be as long as I can find parts and outrun the environmentalist wacko’s.

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