YZ 250 EFI

[2T Institute]

What did Mrs Uniflow say about the lawn? Sounds a lot different to carb engine. What's all that green stuff covering the hills in the backgraound?
Be keen to see if you can nail the injector timing

[evo550]

Is there any other 2t fuel injection systems (snowmobiles, outboards ect) that run premix through the injectors?

[citabjockey]

Sounded pretty good to me - but what do I know? Looks like good progress.

When you make adjustments on the computer is the link wireless?
You guys checking mixture with spark plug checks?
Do you have a cylinder head temp? EGT? Can you set mixture via that?

Thanks for posting this video!

[2T Institute]

Is there any other 2t fuel injection systems (snowmobiles, outboards ect) that run premix through the injectors?

Modern sleds have dry bottom ends with sealed greased bearings and scant oil injection to the big ends, others with very low premix ratios. The premix is a non issue with oil in suspension and very high fuel pressure th oil will do what it's told.

[Uniflow]

Tuning completely by plug and feel / sound at the moment. Injector timing is important, we have it set up similar to the Bighorn but can see this being optimized because the injectors are much closer to the transfer ports. Link is supposed to be developing new software to help, but appear to be to busy at the moment . We still have a lot of options with what we have and this is what we will be playing with in the next while. With little runs like this including short full throttle squirts ( up the road ) the crank case seems oily on inspection but I want to set up the auto oiler before we go too much further, to be safe. I'm sick of having to walk out of trail rides ( early days of the Bighorn FI development ). It's a lot of fun to ride it certainly feels nicer down low speed than my standard YZ. This is the first time I've ridden it so I don't know about top end yet.
Oil in the fuel is no problem, modern injectors love it.

[TMKIWI]

Well done Uniflow.
Good to see it running well so early.

You do realise what you have done, um can't be done according to experts in japan.

[rlaj1004]

Amazing work, you ever thought about making this to sell as a kit? Not sure what the cost would but I am interested>

[Uniflow]

Would love to but at the moment the cost would be high. The Link computer cost $1500 NZD alone. Ultimately a computer board could be made to suit our application MUCH cheaper. At the moment we are just keen to prove this technology can work, In saying that if people are interested I will certainly consider making kits, but lets get some hours on this one first.

[_X_]

f'n sweet!

[Jeram]

Would love to but at the moment the cost would be high. The Link computer cost $1500 NZD alone. Ultimately a computer board could be made to suit our application MUCH cheaper. At the moment we are just keen to prove this technology can work, In saying that if people are interested I will certainly consider making kits, but lets get some hours on this one first.

Wow I didnt realise the Link computer was that pricey.

If only you could get a little $250 netbook computer, install a program on it and then have the loom feed into the PC via a 9pin serial or USB
then zip tie the PC to the airbox hahaha

[Uniflow]

Something like that is getting more and more possible these days.

[Jeram]

Something like that is getting more and more possible these days.

i wonder if anyones been smart enough to create an adroid or iphone app?

you can plug your harley davidson into an iphone and run the tacho through the phone screen, so wouldnt be much harder to install software to control injectors

[citabjockey]

Probably not possible to have a phone app run injectors. Uniflow will correct me if I am wrong but that requires an operating system that specializes in "real time" operations. There needs to be a very direct connection -- with no delay -- between what the CPU wants and the device being controlled as well as in the other direction from the sensors to the CPU. With windows,linux,android etc OS there are many layers that let the computer do many things at once but none of them with real time response. Humans are slow enough that we don't notice it but an injector sure would.

That said I am sure the components on that link computer are pretty darn cheap on their own and fabbing a special purpose board is not that pricy. Its the software NRE that costs the vendor plenty. If enough units are sold then its easy for the price of the whole shebang to come down. But any manufacturer building a bike that gets into mass production is probably going to end up building their own system so development systems like this link are not cost effective either -- and stay that way.

Uniflow -- for your system, how many inputs and outputs are you using? Ambient temp and pressure? O2? throttle position? Rpm (and/or crank position)? Cylinder temp? exhaust temp? Are the only outputs for the injectors? Is there another for the fuel pump? Other outputs? And the link to your laptop -- that is USB? I still think having a WiFi or bluetooth connection with be way cool. Never even bother with a cable connection.

[eprovenzano]

I still think having a WiFi or bluetooth connection with be way cool. Never even bother with a cable connection.

I can see it now...  citabjockey sitting in his big comfortable shaded outdoor chair, an umbrella drink in the cup holder, tapping away on his laptop...  and just screwing with the guys on the track....  And the hole time having a big ****ty grin on his face....   

[citabjockey]

My god -- how did you know?

Lesee, lets give Villo a nice top end cut out. Yes, that's perfect , no power above 5000 rpm.

Ok, here comes Milsaps, Uh Oh -- his mixture is going so lean his $1500 header is glowing red, he he he. Like watching a volcano ready to blow!

Chad Reed has so much fuel now he has flames coming from the silencer! Too bad the bike will not clear the small doubles anymore!

And now JS7 is in the whoops, what now? Nevermind.

Have fun guys!

LOL

I still think having a WiFi or bluetooth connection with be way cool. Never even bother with a cable connection.

I can see it now...  citabjockey sitting in his big comfortable shaded outdoor chair, an umbrella drink in the cup holder, tapping away on his laptop...  and just screwing with the guys on the track....  And the hole time having a big ****ty grin on his face....