The Two-Stroke is only dead if you kill it yourself

By JohnNicholas • on December 9, 2008

We have met the enemy and he is us.

Imagine that a major manufacturer could build an engine that was eight pounds lighter than the typical powerplant, revved quicker, produced ten more horsepower (per quarter liter), had one-tenth the moving parts, cost less to maintain, and could be rebuilt for a quarter of the price of a modern engine. Wouldn’t that be wonderful? Shouldn’t that designer win the Nobel prize?

Think about the ramifications for a second. A lighter, revvier, more powerful, simpler, cheaper and easier-to-maitain engine. Where do we get in line? Sorry but that engine has already been designed, built, sold and discarded. It is a two-stroke engine.

So why is everyone riding a four-stroke? The most commonly stated reasons are the EPA, factory development and increased power. In fact, none of these reasons hold water. The EPA does not regulate closed-course machines. And, if they did, how is it that Yamaha and KTM have avoided the EPA’s wrath since the original 2006 EPA standards were announced? Although it seems apropos that R&D has pushed the four-stroke engine past the two-stroke, nothing could be further from the truth. The development of the modern four-stroke, which started in ernest back in 1997, hasn’t really advanced much in the past 11 years. It might seem obvious that everyone is riding a four-stroke because they are more powerful. In truth, cubic centimeter for cubic centimeter, they aren’t more powerful. They are actually much slower. But under AMA rules, four-stroke engines are allowed to be as much as 100 percent larger. That displacement advantage brings their horsepower figures up to those of the best two-stroke engines.

So why is everyone on a four-stroke? Because we all jumped on the bandwagon. When the public bought the 1998 Yamaha YZ400 in droves, Yamaha’s sales bonanza encouraged Kawasaki, Honda, Suzuki and KTM to get a piece of the action. As more marques joined the fray, four-strokes become the cause celebre. In turn, two-stroke sales waned… and once they diminished below the breakeven point, Honda, Suzuki and Kawasaki bailed out. Who killed the two-stroke? The American consumer did.

Have you ever heard a local racer say. “I’m not gonna swith. There is no way that I’m dropping my current engine for one of those things.” Sure you have, but there is a twist in this quote. It doesn’t come from a modern racer refusing to switch from his trusty two-stroke to a four-stroke. It is, in fact, the words of a motocross racer in 1965 resisting the change from four-stroke to two-stroke.

Forty years after the wholesale switch from British four-strokes to small bore two-strokes, American motocross racers have again abandoned their old school engine in favor for the next big thing. The change may seem inevitable. But is it for you?

The MXA wrecking crew wants to offer you four good reasons to stick with the two-stroke:

Manufacturing costs.

It costs more to produce a four-stroke engine-a lot more. Back when four-strokes were competing for your dollar against two-strokes, there was a price parity between the two. Now that the lower cost two-strokes are gone, the price of the four-strokes will rise.

Lighter.

All bikes use the same running gear (chain. wheel, tires, rims, hubs and suspension), so the only place to save weight is in the engine. That doesn’t mean that it isn’t possible to build a 216-pound 450cc four-stroke, just that the same effort would result in a 208-pound two-stroke.

Fun.

Maybe it is just the MXA wrecking crew, but two-strokes are more fun to ride. The power snaps on, the front end lifts, and the bike squirms under acceleration. They are quick, light and agile. The greatest two-stroke riders are free flowing, hard charging, go-get-’em-style riders.

Maintenance.

Four-strokes cost more to own. Don’t get us wrong; they are cheaper on a race-per-race basis, because they require very little in the way of maintenance. But they are ticking time bombs. All race engines have a finite life-span. When a two-stroke wears out, you inspect the cylinder, thrw in a new piston and get back into action for less than $300. Not so with a four-stroke. If it blows up at the end of it’s service cycle, which is approximately two years, it will ding your wallet to the tune of $1,000 to $3,000.

The MXA wrecking crew isn’t denigating four-strokes. We race them and test them. We are simply stating a manifesto for two-stroke diehards. If you are a two-stroke loyalist, more power to you. You don’t have to feel like the odd man out. Your two-stroke choice is justified-totally.

The complete article above was re-typed from Motocross action. Please visit and subscribe to MXA. http://www.motocrossactionmag.com

tmracingmotorcycles.com/models/tm-racing-2010/

Comments

By reenee on December 14th, 2008 at 11:50 am

Great article, and so true. All you US racers, do as we are doing in the UK and vote with your feet as we now have a selection of 2st Championships for our premix diehard’s, so if a club doesn’t offer a class for you and your buddies either, find one that does or create a class and approach a promoter yourselves ! Great news too, as the UK’s leading schoolboy Championships “The RedBull Elite” are now allowing 250 2st’s in the mx2 or 250f class, lets just see if all those riders that jumped ship, jump back ? “wake up and smell the premix”

By KXROOSTER on December 29th, 2008 at 8:24 am

I went into my local Suzuki/Kawasaki dealer to get some parts and just for kicks asked the sales clerk if he thought the new 2008 fuel injected KX 250’s could beat the old two stroke KX’s..he said”oh you have no idea ..the new bikes would leave those old two strokes a mile behind in the dust!”…I almost fell down laughing..damn salesman! imagine the poor kids falling for that line…as they say…ide rather push my two stroke than ride a four stroke!

By The General on December 30th, 2008 at 11:58 am

Reenee,

You are right… the racers here in the USA that believe in the two strokes should be racing them. Get your buddies together, show up at the track and ask that a two stroke class be added. Whenever two strokes compete many fans get excited. It would be interesting to see how the class would grow after a few races.

KXROOSTER

Every time people talk about the four stroke being faster, they leave out one important factor. Displacement! Yes in most cases if you have double the displacement you will have a faster machine.

Lets see a race between a 125cc two stroke and a 125cc four stroke. Guess which one would win?

By stevemx144 on January 7th, 2009 at 11:25 pm

I do think we should all try and get out of the way manufactures and media hype for the four strokes and make us believe that four stroke is the way. I have had at least 3 four stoke bikes in the last 5 years and I still do not get it,,, fours are nice to ride and easy, but two stokes are the way for me and many other for that matter but people seam to follow trends. I will support 2 strokes here in Scotland Uk and I am trying my best to get my fellow moto xers to convert by simply showing the facts… fast, fun, light, easy to maintain and of course cheaper to run than the fours.

I am now riding a TM MX 144 2stroke. Thanks TM for supporting 2 stoke

By Mick on January 8th, 2009 at 4:43 pm

I’m a little blown away that there isn’t a dedicated 2-stroke class here in the states. I think it really reflects Americans zombie mentallity, and the desire to ride what is perceieved to be “new and cool”. This up and coming generation I see now in the states, they don’t even know what a 2-stroke is / was? When all somebody knows is one thing, they don’t miss the other.

By VintageBlueSmoke on January 21st, 2009 at 5:52 pm

“I have had at least 3 four stoke bikes in the last 5 years and I still do not get it”

Amigos, I think you are missing the point. 4-strokes haven’t taken over becasue they are faster, easier to ride, or make the manufacturers more profits. They have taken over because the US and other governments have pressured them to producing motorcycles that have reduced emissions. Then the marketing teams when to work on the masses to swing you over.

“I’m a little blown away that there isn’t a dedicated 2-stroke class here in the states…”

There will come a day when you will not be allowed to race your CR500 even on a closed course due to environmental pressures.

“Lets see a race between a 125cc two stroke and a 125cc four stroke. Guess which one would win?”

As fond of 2-strokes as I am, with today’s available tech, the 4-stroke would win…because the 2-stroke would not be alowed to start if they had to meet the same environmental standards.

What we need is for someone to build a competitive CLEAN 2-stroke. It’s the only way to save them.

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