Jump to content
Sign in to follow this  

YZ 250 EFI Actual Videos. (Dyno runs, mapping curves and general riding)

Recommended Posts

I'm happy to answer any questions about this bike, if you like.

Edited by uniflow

Share this post


Link to post
Share on other sites

What EFI system is it using ?

How many injectors ?

Have heard of a place around

here that has been working on

FI for 125cc kart motors that

rev to 15,000 + rpm, with some

success.

( big hp success :) ...)

Edited by yamaha7442

Share this post


Link to post
Share on other sites

We have had this system running on the YZ for 8 months now. There has been no real problems, just a Chinese fuel pump failure!

We use two injectors injecting into the rear two transfer ports, pointing towards oncoming air from the crankcase. Injection occurs within the transfer period until higher up in the RPM where we start injection before transfers open. We don't inject after the transfers have shut. This system seems to be very tunable. ECU is LINK ( made in NZ ), it's a standard car unit with our program in it. It delivers similar top end power to my standard bike ( although it can deliver a little more yet ) but power delivery is much  tractable. It appears to be a good reliable sound system. I haven't had to tow it out of the forest yet.

Edited by uniflow
  • Like 2

Share this post


Link to post
Share on other sites

We need to find a more cost effective ECU before it would be marketable.

Share this post


Link to post
Share on other sites

magneti marelli has been doing

high perf EFI / prototype systems

for years .

heard they perfected something

for Aprilia gp 2 stks years ago,

but too much power (?) for the

riders exiting corners. system

was shelved ?!

https://www.google.ca/search?site=&source=hp&ei=Re4nUr3nGu634AODtoAY&q=magneti+marelli+ecu&oq=magneti+ma&gs_l=mobile-gws-hp.1.1.0l5.1937.11865.0.24361.11.8.0.3.3.0.751.3483.3-4j3j0j1.8.0....0...1c.1.26.mobile-gws-hp..0.11.3630.3FeT3_7Cl8E

Share this post


Link to post
Share on other sites

Yes there is plenty of systems out there, just finding the right one, cost verses effectiveness. The LINK is a good unit but a little dear at $1300 NZD never the less it works well.

Share this post


Link to post
Share on other sites

Awesome ! Thanks for allowing us a "peek" ! 

 

Delphi is another USA based "injection" specialty company as well.

Share this post


Link to post
Share on other sites

Any known EFI systems that can support 15,000 rpm on a 2 stroke ?

Most of them dont seem to be availabe

for that high rpm, / have to run multiple

injectors, and run high psi fuel pumps.

Share this post


Link to post
Share on other sites

Regarding that first vid, I guess I'm not going to worry about the noises coming from my engine.  It makes that same "GMC blower" whining noise that mine does.  Must be the straight-cut primary gears.  I think on the same vid, near the end, at idle there is a distinct "ding - ding" sound, that mine doesn't even make.  I feel better now.

Share this post


Link to post
Share on other sites

Converting to efi is going to be a big hit IMO. As ECU's get better and better with maps and A/F sensors its just a matter of time before there will be  a kit for all us die hard 2 stroke guys. I know here is a company in the western states trying to get a ecu produced that monitors A/F ratios 100 times per second and auto adjust for it. I read that on dyno tech

( http://www.dynotechresearch.com/index.htm ) this past winter. Dyno tech is a snowmobile dyno service. When that hits the market ever one will go to a efi as there will be no worries of burn downs at all. I like a carb as it is easy to tune and can be fixed in just a  few minutes my self. But once they have these aftermarket efi's correct I will be switching to one as to be 100% of the time right on the ragged edge with out having to get in the carb is what it is all about IMO.

Share this post


Link to post
Share on other sites

Realistically, it seems that the

technology is all ready here /

been done all ready, and just needs

to be fine tuned, and mass

produced.

The kart place mentioned up

^ a few posts took a 45 hp 125cc

kart motor, stuck on Fi, and

got over 50 hp, but had some

high rpm issues with sensors

Share this post


Link to post
Share on other sites

Did I mention? we are seeing a general fuel saving over my standard YZ250, same tracks, same times. On faster rides down to approx 14%, general forestry type trail ride action we find 20%. I would imagine both bike full out would be similar fuel consumption ( similar power ). IMG_9612_zps62651693.jpgIMG_9625_zpsbb68b8db.jpg

Share this post


Link to post
Share on other sites

Did I mention? we are seeing a general fuel saving over my standard YZ250, same tracks, same times. On faster rides down to approx 14%, general forestry type trail ride action we find 20%. I would imagine both bike full out would be similar fuel consumption ( similar power ). IMG_9612_zps62651693.jpgIMG_9625_zpsbb68b8db.jpg

 

What kind of skid plate is that?

 

I have been installing and tuning cars for years, but in cars I have room for packaging the ECU, the automotive ECUs that I have dealt with (Motech, Haltech, Holley, Accel, etc) have very large ECUs to put into a bike, but I guess one could remove the casing and reduce the size and just be left with a board that needs to be protected.

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

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×