XJ750D... Fuel Injected : does anyone out there have one ?

Max here,

Trying to get my XJ 750 D running
looking for advice from anyone who may have one.

I have a XJ 750 D which I purchased on line from the auctions in Japan about 6 years ago..
This is a fuel injected clone of the 650 Seca Turbo and looks identical. The turbo was not sold in the Japanese domestic market.
The xj750D differs a little in having a bit more bling such as a radio/ cassette and digital instruments with trip computer with various memory functions.. It had 9,000kms ( 5,700mls) on the clock I am trying to get it running. It has side car mountings and a big fork brace so was obviously running as a combo (interesting).

When it arrived the fuel pump was not working, I replaced it. This got it running but would only idle and had no response. I thought I would leave it for a while and possibly convert it to carbs, I purchased a set of 750 Kawasaki carbs to do the conversion and parked it up in a corner of the shed. 6 years later I have dug it out.
I found all injectors locked solid with petrol varnish, same with the original fuel pump. All these bits were cleaned up with acetone.. all working fine afterwards.. and slowly I have been reassembling. Wiring has been a small problem as previous owner in Japan had made changes and wiring code colours do not continue from junctions anyway.. ??
Yesterday I fueled it up... it would fire up with WD 40 sprayed into the airbox.. but nothing coming from injectors..pump running. Just before I left it for the day I removed the tank and put a remote fuel supply in, and had the return line from the pressure reg running to an open container... nothing coming out of the return line.. conclusion ...locked up pressure regulator. The FI system is a real bitch to work on unlike BMW K bikes of the same era. To get to the air metering pulling the engine is really the only way. Having the fuel pump and hoses sitting /jammed on top of an air cooled engine is not ideal... and the contortions the fuel and return lines have to make is pretty crazy.
Hope to hear from anyone who has one ...

 

Can't help you but wow, cool bike. Never knew that model existed. Good luck!

http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj750d 83.htm

 

same here. never knew about that bike. hopefully someone here can help you out!

 

everytime I sync and tune my carbs... I wish i had your bike hehe.
envious much

 

oh... if you want a set of 750 carbs and 5G2 tci to replace your stuff... I'll swap!

 

Contact Yu Tanaka. He lives in Sendai, and should be able to help. The 750D was not exported, so model-specific parts and info will be difficult to come by outside of Japan.

 

So then now we have to look for a fuel injected turbo 650 ........ Lol

 

XJ750D update

Hi and thanks for all the positive comments from all...

I spent about a day recently trying to get it running.... half of that time I wasted as the fuel pump was running but not pumping.
Not a pleasant morning... had the tank off, the inlet hose connected to a funnel suspended from the roof, and the return line running into an open glass container..
The fuel injection system is a continuous loop... gas is pumped from the tank and returns to the tank... what the injectors need...they use.. the rest goes back into the tank.
Most of the time I was trying to fix leaks, and getting covered in gas.. in Australia it's "PETROL"... still stinks the same.

I could have had the pump back the front, but I just disconnected it and put on the airtex pump I bought about 5 years ago.
Again the pump would run, but still no circulation. Not only did I have it connected back the front but just to make it extra complicated it turns out it has a ball valve inside to prevent fuel running back... and that had stuck closed. That was from old gas drying out and gumming up the ball valve.
So some time much later....
All was well with the pumping side of things.. I hooked up the truck battery I was using with jumper leads and the pump fired up and fuel the colour of root beer with spongy lumps filled the glass jar... not good, but at least I didn't have it running back into a fuel tank.
Well OK now I had fuel circulation, so it should start ? Sadly all it did was run for a while on one cylinder... soaking a rag in gas and putting it over the air intake would immediately get it running on all four cylinders. It looks like the injectors are not getting any volts from the controller, and it probably was just running from fuel leaking from a faulty injector, just dripping a bit. I cleaned the injectors and know they were all flowing properly

Yep, so please don't feel jealous if you have to sync carburettors...

Looks like I will spending some time making sure volts are getting to the controller and the air flow measurement gizmo... previous owner had spliced into the controller loom.. maybe problems there, maybe just poor connection...?

Will update soon..

Max

 

Progress!!
And you have proof of the answer to the timeless question, "What's gonna happen to all those new-fangled electronic gizmos in 30 years?"
Well they'll get fixed, just like all those ancient magneto gizmos do.

 

I have a service manual of YFIS (Yamaha Fuel Injection System). XJ750D/D2 were not exported, so English manual don't exist I think. I'll translate a part of manual and post it here tonight.
I wish he had still seen here...

https://www.google.co.jp/search?q=Y...ved=0ahUKEwiWyrXi0cjRAhVHyrwKHWtADz4Q_AUICCgD

 

I'm sure he's sill around. Summer in AUS, so I'd guess that project time has been set aside for riding time.

 

Hi maxwell, I post YFIS (Yamaha Fuel Injection System) service manual pdf file below. Unfortunately, Japanese only. I translated a table of contents and trouble shooting flow chart when injectors don't work. Translating is hard work as you know, so I'll translate only the part you requested for the part you wanted to know. Feel free to ask.

YFIS manual pdf file down load here.
https://1drv.ms/b/s!Aq1ykDbYfkNIaq37WRnP_VwBkR4





Trouble shooting flow chart that you need now I think. This chart show what you should do when injector didn't work.


Good luck!

 

You can say that again.

 

This will be interesting..............