Rebuilding my 907 ST3

[Jaffa]

Pretty difficult I think marrying a mechanical tacho to an electronic one. Perhaps there may be a way to ........ fit the ST3 tacho into the body of the 907 dash????

[JoKing]

Pretty difficult I think marrying a mechanical tacho to an electronic one. Perhaps there may be a way to ........ fit the ST3 tacho into the body of the 907 dash????

Thats what i did and am proud of, see the first picture in my post from 8:21 today.
The look is near 100% original, i implemented the electrical drive from a ST3.
But i do not know how to connect the wiring...(three wires hanging out of the hole...)

[higgy]

Hey G, I think you have a contender here

[paso750]

not a contender just a fellow sufferer

[JoKing]

No, no contender. Just a learner...

One problem w. the revcounter is, that i do not know the original wiring colors.

Next Issue:
Where should the airtemperature-sensor be positioned?
From my car-experience i know, that the sensors most times are in the intake system, near the throttle body. (From my understanding best for correct values for fuel mixture)
In the ST3s parts manual it looks like it is somewhere under the seat.

[JoKing]

Some more pics:

AIrbox fitted to the frame. Because the box is too small (imho), the opening is very wide to the front (effective opening is the frame triangles). I think the air behind the steering head might be calm enough for a good airflow.

[paso750]

Is this how your rev counter looks from behind ?


If so the middle contact is the signal. (see ST2/4 circuit plans) One of the others is 12V ignition and the other one ground (my guess: ground is the right one). Maybe you can measure a short between one of the pins and the mounting screws w/o having to open the instrument to figure this out.
Your wiring colours are not original, are they ? The should be blue +12V, grey/black ground and green/grey for the signal.

If the instrument then works but doesn`t read precisely if the signal cable is connected to the ignition wire or positive output of the CDI to coil you`ll probably need something like this. It boosts the signal.
http://shop.strato.de/epages/61438057.s ... cts/152009

PS:
http://www.ducatiwiki.net/index.php?tit ... schematics
http://www.ducatiwiki.net/index.php?tit ... ons_Manual

[JoKing]

Cool, G!

Let me finish some other work (in special: positioning of all the electronical equipment and making the bike run), and when it runs, i will try to solve the revcounter-topic. I need some extra-time for that.

So again what is in my mind as first issue: where to position the airtemperature-sensor. In the airbox, or out of the airbox?

[paso750]

On the 907ie it`s in the rear side of the airbox. On the ST2/3 it`s on the front panel on the left side of the headlight (parts catalogue P.82)

G.

[JoKing]

Ok, i`ve found it. In the ST3s catalogue its on P.94, #17.

I think i'll install it inside the airbox for correct values...

[907pasonut]

good work there Johannes...but your hand is too clean
...your air sensor may be better outside the air box, as inside may be affected by air resonance and give fluxuating readings...this is the case with some 907s, and one remedy is the old ciggy filter to smoothen things out

[JoKing]

good work there Johannes...but your hand is too clean
...your air sensor may be better outside the air box, as inside may be affected by air resonance and give fluxuating readings...this is the case with some 907s, and one remedy is the old ciggy filter to smoothen things out

Working w. brake-cleaner, parts-cleaner, rim-cleaner all the time... i am lucky there is still skin on my fingers.

What does "fluxuating" mean? My translator does not know that word...

[paso750]

"fluktuierend" in german (schwankend/abweichend), the correct spelling in english would be with ct instead of x

[907pasonut]

What does "fluxuating" mean? My translator does not know that word...

the way I understand it, its similar to pulsation caused by the inlet manifold
this can be more so if you changed the original box design
ps; I spelt the word wrong...fluctuate

[JoKing]

So i am going to install it near the intake then.

Some more Airbox-pictures here, G. asked for them.
Even it does not look very nice ar this state, the airbox fits very well&tight.

First pic:
two funnels w. different length as a try to optimize torque 6 power-output.

second pic:
Funnels in box

3rd pic:
"closed box"