Seriously considering this EFI for 2 stroke

[Mckay Moto Works]

Very interesting product, waiting on a call back from the developer, a former 30 year GM employee.

http://twostrokemotocross.com/2011/09/ditching-your-two-strokes-carb-for-port-fuel-injection/
http://www.highgaintuning.com/

[jrotten99]

Looks like a lot of money for little return.

[patricks]

I've emailed Richard a few times and he seems like a nice bloke. He's working on a bolt-on kit for Banshee engines at the moment, it's going to be sold thru Wicked Motorsports when it's ready. 

As far as performance goes, if you're looking for more top-end horses then it is a lot of money for little return - the single cylinder kits are about $1,300, so my guess is the twin kit would be around the $2,000 mark. That's just my guess, it's not based on any info from Richard. The main performance gains for an unmodified/lightly modified RD/RZ motor are low and mid-range, cos the fueling's more precisely controlled.

Richard reckons the kits will mostly appeal to moto parents (accurate fueling means less chance of eating a piston if you've got the jetting wrong and means Mum and Dad don't have to spend all day fiddling with Junior's jetting) and ultra-high performance Banshee freaks. That's where the real performance gains are, those $10k, 140hp drag Banshee engines apparently pump so much air the carbs can't keep up, so FI gives them perfect fueling at any load.

He's said before that he's not doing any kits specifically for RZ or RD engines (too small a market), but I reckon the Banshee kit should bolt straight onto an RZ motor and probably wouldn't take too much fiddling to attach it to an RD.

If FI is really what you want, a Megasquirt or Microsquirt unit will be much cheaper, but you've got find bits like injectors and fuel pumps and set up the tuning software yourself. I think at least 1 person on this board has injected their 2 stroke and a guy called Smurph on the RZ/RD forum has done it (http://www.smcomp.com/~smurph/RZ-EFI/index.html).

I want to play with fuel injection at some point, but it's a mid-to-long term plan - time, location and money don't allow for it at the moment

[joeschuite]

As someone who has attempted and partially succeeded at fuel injecting my gt250, the main points you'll need to be aware of is the tach signal and alternator power.  If you have a vintage smoke ignition or similar, is is very easy to splice into the sensors for a tach signal.  However, points are a bit different and reliability and consistency are what you should be striving for.  Secondly, you'll need to have about 100 watts of extra alternator power, something that I havent' been able to find yet for my gt.  I know of aftermarket banshee stators that are at 200 watts, and work very well.  Mabye it'll fit on rd's with little modifications?  As for overall cost, I've got about $800-$1000 into my setup.  It's plenty of trial and error to get it right.  If you're looking for bolt on and go, pick up a cbr250 and be done with it.  If you'd like to learn more than you'd ever want to know about fuel injection and become an expert on it, then go for it.  Thanks, Joe

[desmodrew]

   After eight years of development, Bimota still couldn't get fuel injection to work on the Vdue.  I believe it is the model that bankrupted Bimota (one of the times, anyway) because they spent so much trying to get it to work.  Two strokes just seem to like carbs.  I believe Honda even tested it on the 500GP bikes. It just doesn't seem to work.  Sure, you can make a bike 'run' with fuel injection.  And if that is the goal; to make it 'run', and fuel injection is simply an exercise in mechanical and electrical engineering, go for it.  But always remember that factories, with dumptruck loads of $$$$$ couldn't make it work well enough to ever sell it or race it.

[r5baker]

Is that true that none of the later GP 2-strokes were fuel injected?  I am surprised if that is the case...  There would seem to be so much to gain having advantages such as fueling and timing controlled by an ECU that could compensate for temperature and pressure as well as provide data logging capabilities, just to name a few.

Haven't 2-stroke snowmobiles been injected for some time?

[raysorenson]

The bimota EFI is a unique animal. They were wrestling with keeping emissions down while a DIY EFI project only addresses clearing up a carb's weak spots and spark timing control.

The nice thing about homebrew EFI is the availability of cheap throttle bodies with a fuel injector, fuel rail, throttle position sensor, intake air temp sensor and some sort of fast idle provision all packaged together. The bad thing about the throttle bodies is that the throttle plate restricts air flow.

Megasquirt will work with points but as already mentioned, the current draw of the fuel pump will likely be too much for the generator.

[desmodrew]

  That is correct.  And a lot of the new outboards are injected.  I think it is great.  Injected two strokes are a brilliant idea.  I think most inject directly into the top of the combustion chamber.  Yamaha outboards inject fuel at 1000psi.  WOW.  Purpose built engines can work very well.  But trying to force fuel injection to work on a 40 year old two stroke engine design seems like a whole lot of work. But if someone needs to prove they 'can', then go for it.  I've done that plenty of times myself.  In the end, after adding lots of wires, boxes, probably a bigger charging system, adapters, O2 sensor, etc, it will never look as cool as a pair of Lectrons, and will probably not work as well either.

[Biz]

Check out the April '12 issue of Cycle World, there is an article on the new fuel injected Ossa 2-stroke trials bike.  Doesn't have a lot of detail, but it's cool that at least there are efforts by somebody, even a tiny manufacturer, to create a fuel injected 2-stroke.  Yamaha had fuel injection on watercraft several years ago, I rode my friends fuel injected GP1300 which is a 1300cc 2-stroke triple.  Had an amazing power hit and did 75-80 on the water.  I guess it's easier to design when you only use it at WFO throttle.  But unfortunately they discontinued it.  And it was always broken.

[patricks]

I found this while doing more "homework" last night, it's a kit designed for small 2 stroke engines: http://www.ecotrons.com/2_Stroke_Small_Engine_EFI_kit.html
It's cheaper than the Megasquirt or HGT's kit and unlike the Megasquirt it comes with throttle bodies, but you may need to adapt it to fit the manifolds and you have to do the mapping yourself. 

I've heard from a few people, though, that a well sorted carb is better than a poorly sorted EFI setup, so if it's crisper throttle response and smoother performance you're after then the UFO mentioned in the other thread, plus a dial-a-jet and a little dyno time will probably get the same results as the ecotrons kit for heaps less money. If you want an easier install, more precise fuel metering and lower emissions (did I just say a swear word?  ) then HGT's kit is the way to go (he writes a map specifically for each engine layout that he develops a kit for).

As far as watercraft go, my mate's bass boat has a Yamaha HPDI (high pressure direct injection) engine on it and it hauls ass!

[m in sc]

IN A NUTSHELL, BIMOTA HAD A PROBLEM WITH THE INJECTOR SUPPLIER SPECS. sorry caps. the protoypes worked very well actually.
just saying.

epa wont allow a carbed vehicle anymore. needs to have engine management like fuel injection and an ecu.

[Damon]

all the epa and bimota etc stuff aside...  it seems like if EFIing a two stroke was cost effective and yielded a worthy result...  the 2-stroke 250cc MX bikes would have a system on them by now.  Been on the 250f and 450f machines for a while... and as anyone who has ridden both knows, the an EFI 250f is in a completely different zipcode as far as throttle response.  I also spent some time with a 2010 YZ450 and the throttle response was too good.  I hated that machine it was so damn powerful... if you looked at the throttle wrong it would go.

Doesn't seem like it would be so hard for say Yamaha to fit one of the current systems onto a new YZ250 but they don't?  a 2012 yz250 2-stroke still comes with a carb.  Maybe that's to keep costs low but if the bike (with efi)  worked better, were more reliable and made better power....   

[Surewin]

The EPA doesn't mandate fuel injection on vehicles, only that it pass emissions criteria. 

It looks like there is some confusion between fuel injection and direct injection.  DI offers more challenges to design and implement especially on a 2S where time for injection is limited if it must be done after the exhaust port closes.

Fuel injection offers far more flexibility and control of fuel metering then carburation.  Whether the fuel demand can be actually measured and if the engine architecture allows for other FI benefits are another story.

[raysorenson]

It looks like there is some confusion between fuel injection and direct injection.  DI offers more challenges to design and implement especially on a 2S where time for injection is limited if it must be done after the exhaust port closes.

Thank you.

EFI has some specific advantages over carbs that would require a lengthy and technical explanation that may not belong in this thread. However, comparing EFI to production 2 stroke direct injection system will only muddy the waters for those who are currently a little fuzzy on 2 stroke EFI systems.

I suggest that anyone thinking of going to EFI consider the usage of the bike. EFI should be considered for a daily driver, but setting up an EFI system to wring out the last bit of horsepower over the best carburetor setup will be in uncharted territory.

[retaRD]

To the OP,
Tune the bike with carbs like millions of people before you have done, stop chasing unicorns and ride.
My 2 cents.