Jump to content
Sign in to follow this  

Direct injection two strokes

Recommended Posts

With Direct Injection concept getting closer and closer to being on our shelves, how will this effect the market? Will we start to see Japanese companies competing with 300 two strokes & possibly overtake the amount of 4 strokes we are seeing on the track? I cannot wait!! 

Share this post


Link to post
Share on other sites

Nope. I have no expectations at all for this.  As cool as it may seem,  we are not in a time where companies will be making a huge risk like this.

 

I disagree.   I think we'll see KTM stomp on this.    KTM has been the ONLY company out there pretty much signing blank checks for R&D.

 

KTM lagged WAY behind in the fuel injection (and it was a HUGE benefit to them to do so), but I think they'll be leading the way with 2 stroke direct injection.

It's not uncommon on watercraft already .

  • Like 2

Share this post


Link to post
Share on other sites

I think throttle body efi would be nice on a 2 stroke. I would not want a direct injection 2 stroke

 

We like our pingers because they are

light weight

simple

cheap

 

 

dirt inejction ruins all of those things.

  • Like 3

Share this post


Link to post
Share on other sites

This is supposedly from the latest issue of TBM. Trail Bike magazine. "and we take a look at the direct-injection two-stroke dirt bike you may well be riding in 12 months time. And would it surprise you to know that it might be Japanese?" I don't get the magazine, so I can't confirm. I saw it mentioned on another site. 

Share this post


Link to post
Share on other sites

From the new Dirt Rider

 

 

 

"How would you react if i told you that in the not so distant future, one of the major Japanese manufacturers is going to release a direct-injected, off road 2 stroke? Although not yet official, this juicy rumor seems to be based on more than just speculation, and its verification would certainly serve as proof that the manufacturers are responding to the plea's of premix-starved consumers who have taken every opportunity to flood inbox's, message boards and dealerships with the same basic demand: "Give us back our two strokes!"

Don't get me wrong; modern four-strokes are amazing machines, and they definitely have their advantages. I'm of the opinion that two-and four-strokes can coexist, and i would love nothing more than to return to the days of doing combined 250/450 super shootouts. But there's a strong precedent for bringing back two strokes, and its based upon the tried and true KISS principle: Keep it simple, stupid. We all know that these bikes are easy to maintain and modify, whereas putting a rod through the cases on a thumper effectively turns the motorcycle into a very expensive downhill-only mountain bike.

Riders miss the days when a top end change could be completed between moto's and post race maintenance didn't include a valve check. Yet it should be remembered that if the manufacturers begin reinvesting in two stroke technology, the end result would not be as simple as we think. If it took EFI tuning soft-ware and a laptop to make your new two stroke's jetting richer, would you still want one as badly as you do now?

Many of the initial justifications for manufacturers to turn to four strokes (and EFI) were environmental. Part of the emissions allegations against two strokes is that back when these bikes were regulated off road, the oils used were primarily petroleum based lubricants with extremely rich oil ratios, and the gasoline back then was simply not as clean. Even with carb's, two strokes today are much less "emissions dirty" than they used to be, mainly due to decreased particulate matter and much leaner oil ratios, thanks to advancements in premix oil's. In other words, there is no reason why current carb fed, premix burning two strokes can't be made to comply with EPA and National parks reg's, just like snowmobile and marine two strokes have been.

On the tech front, EFI would be a progressive innovation to see in production on a major manufacturer's two stroke, primarily because carb's do not provide a reliable shut-off, so unburned fuel is always present in the exhaust. EFI will partially minimize many of the pollution complaints about carbureted two strokes, but it won't be completely eliminate the unburned fuel passing through the cylinder and out the exhaust before the compression and ignition occurs, which is the biggest allegation against these bikes. To significantly clean up two strokes, DI will be required, which would occur after the exhaust port is closed. 

That is something that we've not yet seen in a production off road motorcycle, but DI would allow the addition of an oil ring that would lubricate the motor like a four stroke, since the gas would always be above the piston. Translation? No more need for premix, no un-burned gas emissions and possibly a lower compression ratio for less overall stress on the engine. What's not to like about that?

Of course, i'd remiss if i didn't' give props to all of the manufacturers who continue to invest in two strokes, or at the very least have not abandoned them completely. You can continue to show your support for two strokes by communicating your desires to these manufacturers, both verbally, through letters and emails, and most significantly by where you put your money. And while you're waiting for new technology to emerge, consider this: Word on the street is that KTM's direct injected 2 stroke model is already complete, and evidently their prototype EFI two stroke feels every bit as smooth as four strokes in terms of delivery. But if- and the operative word in this sentence is IF- KTM's new wonder bike is already fully operational, why not release it to the public? 

All we can do at this point is speculate, but my sources on the front lines in Europe claim that KTM is waiting for the previously mentioned Japanese manufacturer to break the DI two stroke ice and release a red one first. However this ends up going down, when the manufacturers get this technology right, and believe me, they will get it right. The end result is going to be awesome enough to make even the most die hard four stroke owner think twice about his or her engine of choice. "


Dirt Rider Magazine
Page 24, September 
 

  • Like 6

Share this post


Link to post
Share on other sites

With Direct Injection concept getting closer and closer to being on our shelves, how will this effect the market? Will we start to see Japanese companies competing with 300 two strokes & possibly overtake the amount of 4 strokes we are seeing on the track? I cannot wait!! 

 

 

At the professional big money sponsored hired gun rider level of MX, I think 4 strokes will be around for a long time.     Offroad racing and amateur mx the 2strokes are already making a comeback without DI.  Not sure I'd buy the 1st year 1st model DI dirtbike when it comes, Went through all of that with skidoo and there were a ton of teething problems and numerous reflash recalls.

Share this post


Link to post
Share on other sites

Indirect injection is a good compromise, not throttle body injection as that does not work so well but transfer port injection. Injecting into the rear ports and timed right reduces the fuel spillage out the exhaust. Our test EFI YZ250 shows 14% over a standard unit already without any serious R and D. I'm sure with time we could get around 20% saving compared to a standard YZ. Same top end power but much smoother mid range. Cheap simple and reliable ( so far ).

  • Like 1

Share this post


Link to post
Share on other sites

What I don't get is the 300 number. What on earth is wrong with 450? The OEMs could make a wonderfully understressed two stroke 450 that would rock hard core and last like taxes. Don't think so? Check out the outboard boat motor industry. The Yamaha 4T displaces 2785cc (163.0 ci). The Evinrude 2T displaces 2,589.16 cc (158.00 ci).

 

Two stroke. Game, set and match.

  • Like 2

Share this post


Link to post
Share on other sites

 could make a wonderfully understressed two stroke 450 that would rock hard core and last like taxes.

 

 

I like understressed. (although the real world of magazine tests and peer pressure would demand that a 450 would have to make about 100 hp)

Share this post


Link to post
Share on other sites

 

All we can do at this point is speculate, but my sources on the front lines in Europe claim that KTM is waiting for the previously mentioned Japanese manufacturer to break the DI two stroke ice and release a red one first.

Would that mean Honda?

  • Like 1

Share this post


Link to post
Share on other sites

What I don't get is the 300 number. What on earth is wrong with 450? The OEMs could make a wonderfully understressed two stroke 450 that would rock hard core and last like taxes. Don't think so? Check out the outboard boat motor industry. The Yamaha 4T displaces 2785cc (163.0 ci). The Evinrude 2T displaces 2,589.16 cc (158.00 ci).

 

Two stroke. Game, set and match.

 

 

why would they build something that wouldnt break as often so they dont sell more parts 

  • Like 1

Share this post


Link to post
Share on other sites

I think throttle body efi would be nice on a 2 stroke. I would not want a direct injection 2 stroke

 

We like our pingers because they are

light weight

simple

cheap

 

 

dirt inejction ruins all of those things.

 

I'm not so sure it will ruin those things.  A direct injection two smoker still has the simplicity of a piston that basically controls its intake and exhaust.  The DI system only adds a little different injection, so it'll add a bit of weight there.  But the jug is not encapsulated by rockers, valves, springs, timing chains, etc of four strokers. 

 

Seeing DI take off would be great, you can see some info about the concept here

 

http://www.youtube.com/watch?v=eu3NEPSBfUs

Share this post


Link to post
Share on other sites

I don't understand KTM's hesitance. From an uneducated pov such as mine, it seems like the 2t market is heating up. KTM is *mostly* looked at as the smoker colorguard. Why let someone else steal your thunder? They have the diversity to add a single DI (II?) model, say a 250 SX-i, to test the waters without cannibalizing the sales of too many other models. If it works out as a hit with riders, they phase out the SX and move on to the XC. I like the idea of indirect injection as well. Gotta find that balance with simplicity in 2-strokes.

Share this post


Link to post
Share on other sites

KTM has been sitting on the technology for a few years now.  In fact, they were supposed to debut it in Europe for the 2014 model year because Europe passed new emissions laws that would basically outlaw all the 2 strokes.  Since 2 strokes never went away in Europe and are very popular, KTM came up with FI to lower emissions and keep their new bikes street legal.  For whatever reason they didn't do it this year in Europe.  My guess is its coming for the 2015 model year and most all of the 2 strokes will be FI'd...

Share this post


Link to post
Share on other sites

The word I heard from a high up in Europe....

Husaberg was supposed to debut the DI last year, but they're still having teething problems.

Word is also the Japanese are working on it.

It basically sounds as everyone is scrambling to release it, but no one has gotten all the bugs worked out yet.

Share this post


Link to post
Share on other sites

And what the snowmobiles went thru in developing the di or indirect fi should be a non issue. The improvements they accomplished did not exist in a secret place in Iceland.  All this info is known to every mfg in the engine business, almost nothing is proprietary. The teething process with bikes should be very minimal if at all. I still love my totally reliable, simple, non sensored carbed bikes but the injection thing is coming. Period. My main excitement is that we may get an updated 2stk from the Japanese.

Share this post


Link to post
Share on other sites

KTM has been sitting on the technology for a few years now.  In fact, they were supposed to debut it in Europe for the 2014 model year because Europe passed new emissions laws that would basically outlaw all the 2 strokes.  Since 2 strokes never went away in Europe and are very popular, KTM came up with FI to lower emissions and keep their new bikes street legal.  For whatever reason they didn't do it this year in Europe.  My guess is its coming for the 2015 model year and most all of the 2 strokes will be FI'd...

 

Husqvarna was working on this a while ago too, for street use.

 

Guess who owns Husqvarna now.....

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×