Yamaha TRX850 Enthusiasts Forum

hello, has anybody made aftermarket efi- system to their TRX/TDM's. All advice wellcome since I live still in carb time....

Ignitech make them for the TRX. Programmable and very user friendly and easy to change from the default settings if needed but not really necessary unless you've done a bit of engine work or anal about fuel economy.
The money they charge for dyno time you can easily buy and fit an wide band O2 sensor unit with real time digital readout to sort your fueling too. You can tinker a little with the 3D 100 point mapping if you choose from there.

cobbadiggabuddyblooo wrote:Ignitech make them for the TRX. Programmable and very user friendly and easy to change from the default settings if needed but not really necessary unless you've done a bit of engine work or anal about fuel economy.
The money they charge for dyno time you can easily buy and fit an wide band O2 sensor unit with real time digital readout to sort your fueling too. You can tinker a little with the 3D 100 point mapping if you choose from there.

Ignitec make a fuel injection system Brian ?
I'd have thought the tdm900 might have been able to be adapted somehow...not worth the trouble of fitting a fuel pump in the tank and maybe using the Tdm head for the injection inlet flow.
But then the Tdm head doesn't have the frame mounting link.

Yes Alex, Ignitech make a number of ignition module formats including the Ignijet models for fuel injection.

But Rane mentions he is still in 'carb time"

As for the O2 sensor unit I mentioned...
$250 gives you a all cabling and bung, Bosch O2 sensor plus an Innovate wide band O2 gauge which has the software built in to record and download information and also a real time digital reading from the gauge face.





You can see where I've welded the bung into the headers to screw in the O2 sensor or if you choose you can place it the back of the collector if you have a 2-1-2 system similat to an Over Racing collector.

I would be interested in a kit for fuel injecting my Rex.
I understand that Dynojet has been favoured in a lot of already fuel injected motorcycles and essentially our ignitec programable ECU is similar.
But that's only for bikes with the fuel pump ..fuel rail and injectors already in place.
Haven't heard of anyone making a kit to make a previously carburettored bike motor to be then fuel injected is all I'm on about.

Rane850 wrote:hello, has anybody made aftermarket efi- system to their TRX/TDM's. All advice wellcome since I live still in carb time....

Never heard of one.
There are ECU's as has already been mentioned, and some have fitted TDM-900 bits to their 850's, but I don't know of any EFI kit or even a bike you could take it from.

should put my glasses on...didn't see the EFI bit

Been there myself Brian,..but on the FBook postings recently, there was a Tdm900 motor installed into a trx , and the builder used the trx stator /ignition sensor.
Apparently fitted straight on to work with the trx Ignition module.
The tdm900 motor was then fitted with the fcr41 carbs which is fair enough.
But if I was to try a fuel injected Rex, I'd fit the Tdm head and inlet manifolds/ injectors,with a welded on frame lug,..inter grate the Tdm wiring harness from the stator to the Tdm ECU,..fuel rai and high pressure lines with the fuel pump inter grated into the Rex tank..( just take the whole cut from the Tdm again.)
Being a panelbeater, that isn't an issue.
Mind, all this is one of those ..I can so I will ..builds and the machine is running well enough anyway, so why would you...
Which is probably why we haven't seen anyone do such a mod..yet...ha ha

Dicky, you might remember the member here QUANTIME , 1998 or so,..down Melbourne way I think who was building an injection system for his Rex, if memory serves he was building from Volvo parts and never finished the project.

for what it costs you would be better off buying a TDM900 and transplanting the lot including the engine into the trx.

get the fuel injection and a host of other benefits while you are on.

Thank you all for you answers. My thought is that if TMX carbs will cost appr 1000€'s could I get with same money EFI systems which would be easily adjusted. I have looked briefly those Megasquirt systems, my friend has made this in his race-Toyota... so I cannot be worse than he is.
Needs would be: throttle bodies ( R1, salvage?), injectors ( see prev), fuel pump (salvage, car?), ECU, sensors (DIY Megasquirt) and help from local machining shop.
This could be sooo long project that pls dont hold your breaths!

Quan was a very skilled engineer, works on nuclear subs so `may` be in another part of the world now.

I certainly do remember Quantime. He could finish in a day what it would take me a month. Access to all the good tools certainly helps, but he had no shortage of skill.
If he is working on them nuclear subs as Mince suggested then he's no longer in Adelaide where he originally was.