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Author Topic: YZ 250 EFI  (Read 70923 times)

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Offline Lolerbabop

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YZ 250 EFI
« Reply #30 on: February 27, 2013, 11:45:51 AM »
MORE PICS PLEASE!!!!!
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Jeram

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YZ 250 EFI
« Reply #31 on: February 27, 2013, 09:01:31 PM »
Jearm, we still haven't done your job yet!! Sorry, we have had some deadlines to meet ( you know, the work that pays the bills ). Phillip tells me the drawing is not quite on center. I think he has adjusted the drawing to suit now. Phillip will look at Monday or Tuesday to put your job through.

This throttle body you see here is to fit into the space on a YZ250 where the carb was. It still needs some machining to the inlet where the air box rubber boot fits. Cylinder still needs the injectors fitting, I've welded lugs on but not machined them yet. For some reason we are loaded with work at the moment ( you know real bill paying work ) and these jobs have to take a back seat.

In saying that I've set aside this weekend as a YZ360 cases patten, weekend.

Ah fair enough, i forgot this one is going on a stock YZ250!
when its disc valve will you run a trick airbox on the side of the motor like the aprilia GP bikes?

If there were any errors in my CNC CAD drawing thank Phillip for finding them before it was too late
tell him as long as it has a 20mm butterfly and the same ID/OD for the exhaust pipe/cylinder mounting etc he is welcome to fiddle with it to his hearts content.

Looking forward to seeing the disc valve 360 cases! If I didnt already have as million and 1 projects Id buy one
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Uniflow

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YZ 250 EFI
« Reply #32 on: February 28, 2013, 01:41:23 AM »
Jeram, because the YZ360 throttle will now controlled by the vairable disc valve housing only, no other throttle valve, ( shuts right off, computer driven ) the inlet can be very short so a nice bellmouth into a still air box is a probability. I'm looking at opening a cavity inside the crank case to change volume as the rpm's rise, linked to this throttle slide.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Jeram

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YZ 250 EFI
« Reply #33 on: February 28, 2013, 11:59:05 PM »
very nice!
be sure to use the bell mouth forumulas!


Also if you want to try something else trick, make sure there is a little bit of clearance inside the cases so that you can use the insulating paint talked about on pit-lane.biz, part 2, page 39
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Uniflow

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YZ 250 EFI
« Reply #34 on: March 02, 2013, 08:34:13 AM »





It's taken all weekend but here is one case pattern, split on the part line, rotary valve port will be CNC cut straight into the casting when it's being machined ( better finish and more accurate ). There will be a cover machined and bolted over the lightening pockets, where the rotary valve sits. This will be the inside rotary valve face and made of or plated with something slippery. Next will be the left hand case.
I will be painting these patterns.
All machined at  three degrees taper.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Jeram

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« Reply #35 on: March 02, 2013, 11:43:26 AM »
very nice!
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Uniflow

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YZ 250 EFI
« Reply #36 on: March 08, 2013, 11:21:06 PM »




Suitable bike to use, not cleaned from last ride!!



Injectors in place, still need to make the fuel rail. This will be connected to some head studs.



All the bits are starting to come together for the YZ250 EFI project.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Stusmoke

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YZ 250 EFI
« Reply #37 on: March 08, 2013, 11:27:22 PM »
Awesome work Uniflow. You're the guy that should be designing Yamahas two stroke motors at the factory.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline 2T Institute

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YZ 250 EFI
« Reply #38 on: March 09, 2013, 01:16:09 AM »
You should be able to get some true 3D mapping, when linking to TPS, richer in the mid range for drive off corners. The injectors fire alternatively, IIRC your tricking the ECU to think it's a 4T twin?
Making it disc valve is a master stroke, pissing those flapping reeds off is brilliant. Did you end up incorporating a balance shaft?
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline bigred1977

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« Reply #39 on: March 09, 2013, 10:49:34 AM »
thats some fantastic work there, i can only simpathise with the amount of hours you must be putting in with this project. :o
i would just like to add my ten cents worth regarding the yzr500fi. i feel its only right as i was the person who designed and built the whole bike, including its efi system.
the reason the bike ever eventuated in the first place was due to the fact, myself and my partner agreed to do it for free! yes for free.
the owner keith patterson who is now sporting a carburettor on the very same bike was the biggest hurdle in the whole venture.
frankly speaking the man is thick as two short planks and no amount of explaining or lodgic will ever sink in.
the reason he pulled the efi off the bike was down to being a tight arse, he would not shell out $600 for a stator capable of the current draw on the efi, so when batt voltage dropped below a certain threshold the bike word run ****. simple stuff. not for keith.
any how i turned my back on him. and now reside in australia, i have made numerous kits that all work fantastic, all port injected.
there is alot of time and research into making hybrid systems work such as these, i have no doubt yours will work great too, i can only commend people such as yourself.
i did not want to detract from your thread, however reading the part about the yzr500fi, that had to be put straight.

am intersted to know who you are? where abouts are you located?
cheers mark.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Stusmoke

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« Reply #40 on: March 09, 2013, 11:55:45 AM »
Hey Uniflow what made you choose the YZ?
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline jar944

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YZ 250 EFI
« Reply #41 on: March 09, 2013, 02:22:47 PM »
I can't wait to see how this turns out.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline cnrcpla

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« Reply #42 on: March 09, 2013, 07:07:53 PM »
This is shaping up to be awesome  :o
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline Uniflow

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YZ 250 EFI
« Reply #43 on: March 09, 2013, 07:25:42 PM »
Mark, we have talked over the phone. I'm the person that is running a EFI Bighorn Kawasaki. I also have had voltage problems, my regulator had been going open circuit from time to time dropping the voltage below 11 V . Engine would run lean for no "apparent" reason. All sorted now.
I have had a lot of trouble getting the Bighorn to run clean low in the revs until I changed to injecting just before transfer ports opened, I inject into the crank case at the catchment area to the rear port. This was done because I needed to hide the injectors from eyes. As it happened this was exactly the right thing to do. Link are bringing out new soft ware that will make transfer port timing even better. Should be mid this year ( soon! ). I didn't want to down grade your efforts, I just found it surprising that after all that effort to see a carb on the EFI CR500. Incidently the owner says he still can't get the carb to run right, down off idle.
« Last Edit: December 31, 1969, 04:00:00 PM by ' »

Offline TMKIWI

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YZ 250 EFI
« Reply #44 on: March 10, 2013, 06:21:25 AM »
You know you are going to have to let me ride that Uniflow. ;)
You going to Halcombe ?
« Last Edit: December 31, 1969, 04:00:00 PM by ' »
If you don't fall off you are not going hard enough