Electronic ignition system

Hi, anyone help re Ducati electronic ignition. 860 gt engine
I have fitted the transducers and connected the two sets of wires as marked
ie, red,green,white and earth wires and. plugs leads to plugs…
1st question do I need to connect a 12v supply via ignition sw?
2nd. how can you identify which set of wires goes to which transducer/ cylinder? (the wires come out of the c/case and they are the same colours for each lead.)
3rd. assume all is well . I now need to stop the engine! do I connect an earth wire, via stop button, to the green wires on the transducers ( they each have a double connector which would seem to allow this)
any help or advice appreciated. cheers phil.

Hi Phil,
I can’t really help you with your problem, I’m just suprised that the original system is still running!
I can’t remember the switch gear on the 860’s, but the 900SS never had a kill switch fitted although the Drama’s did, the SS models being fitted with a quick action twin pull throttle assembly.
You stopped the bike by turning off the ignition switch via the key.
Also my original loom on my '79 900SS had a loop in the loom for a kill switch to be taken off from.
I wired mine through the indicator switch as I’d removed the winkers inside a week of ownership.
(If it’s not fitted it can’t break when you drop the bike, so until the law changed I’d always removed the winkers).
The kill switch didn’t take the power to earth but just broke the circuit…No power = No spark.

Steve R (South)

Hi Steve, the bike is a cafe racer type special which i have sort of put together. I originally had a rita ignition with coils which i understood ok, but bought a recon 860/900 engine last year and it has the ducati built in ignition with stator thingy on the crank. managed to get the transducers from mdna italia and now ready to start her up, but was wondering how to identify front and rear? the engine kill question was just a thought as it is easy to press a button and kill the engine in case of emergency. My real puzzle is whether or not the ignition needs a low volt supply as the rita did, but cant see where it would connect too ,have looked at wiring diagram for 860 and its not that clear with all the other items on the drawing, I have made my own wiring loom albeit much less complicated,only supplying bare essentials .I have turned engine over and it does appear to produce a spark, but i cant figure out how?
cheers phil

Hi Phil,

I used to have a 860 with Ducrappi Eletronnica ignition, but that was a long time ago, I’m afraid! However …

I’m pretty confident that the system is essentially the same as what’s on my SCR, in which case:

  1. Yes, the ignition kill works by shorting the transducers thru the green wire.

  2. The SCR uses a magneto coil to provide current for the transducer, and having first thought no, I’m now pretty sure so does the 860. The 860 workshop manual, bevelheaven.com/, describes something called an “Electronic Ignition generator” - viz pg 106 - and goes on on page 149, “The ignition is of the condenser discharge type: the electric power of the generator output goes into a condenser etc …” So, yup, no battery required!

As to which cable goes to which cylinder, page 149 says, “The red cable must be connected to the transducer of the vertical cylinder”. So sounds like you’ve got to convince yourself one of those cables look red! Frankly, if you hook up wrong, you’ll know and you won’t do any damage.

Ciao

Craig

Good stuff there Craig

The original wiring uses a relay to ground the green wires.

The good news about the Ducati Electronica ignition is that its self generating and even if you have problems with the rest of the charging system the bike will run.

The bad news is that the advance is more of a step than a curve…

If you want to keep the electrics simple, replicate a single electronic ignition wiring scheme where turning off the ignition switch grounds the green wires.

From the 860 diagram I’ve got it looks like both front and back pots have the same colored wires :unamused:

But you’ve got a 50/50 chance of getting it right and can easily swap over if if doesn’t fire up.

Many thanx Craig, have checked all your info and I can now continue with more confidence.I seem to now have a problem of petrol pissing out of one of the carbs, think the float needle is stuck?
I note that maybe the Duccrapi ignition is not up to much compared to say the rita system, what problems am I likely to encounter? I still have the rita but the ducati version is much neater ie no ugly black box ontop of the bevel cover.
Any way many thanks for your reply
cheers phil

Just seen your reply arj, many thanks . If I am lucky and can sort the carbs out by next weekend I may hear the sound of a pair of conti’s trying to blow the windows out of my garage!!! or I may be in hosptal with broken ankle?
cheers phil

Hi,
It’s almost 30 years since I played with a Ducati Electronica ignition system but…
The wires being the same colour wouldn’t be anything to do with there being a wasted spark ?
If that’s the case then it wouldn’t really matter which way round that they’re conected??
The two pickups/poles being there to make sure that the sparks come 90 degrees apart.
I run a RITA on my bike but because of the bevel gazer it runs off the front pot, it works OK but I worry about it’s ability to withstand an off, it looks to be one of the 1st places to hit the deck down there.
I’ve been looking longingly at the Moto Witt DMC/2 900 system but at about £500 plus p+p from Germany for the complete set up inc’ new coils and pickups, I’d need to sell off a few of my much cherished bevel spares and also the RITA.
The trouble being that the day you sell a spare is probably the week or two before you find that you needed it for yourself.

Steve R (South)

No worries Phil - hope it helps.

Petrol coming out the carbs? Yup, float needle or floats worn, sticking up etc. Also, the floats can get hung up if you aren’t careful putting the float bowl back on. Take it all apart, give it clean, reassemble and try again …

If you have to replace the needle, just be aware that some people have reported problems getting the new needles to seat properly. Any one had this problem recently, btw? I haven’t heard of anything for the last year or so … Maybe Dell’Orto have got over it now?

The Ducrappi ignition is generally fine, at least all the time it’s working :slight_smile: … It’s mainly the transducers that fail; but, hey - they’re 30 years old now. You can get them repaired - Phil at Road 'n Race, for example. But it’s not cheap.

Otherwise, as Andrew says, it’s commonly held that the advance is too crude and/or sudden and/or early and this has been linked to premature big-end failure. Me, I don’t have the knowledge to endorse or refute this, especially given that big-end failures are blamed on so many things …

Ciao

Craig

Hi Steve,

Yeh, I kinda wondered that myself before I penned my earlier message to Phil; but the fact that the workshop manual makes a point of instructing you to connect the “red” (Ha! What “red?”, I hear Phil ask!) lead to the back pot, made me think, ‘Maybe not …’

(And, just for the sake of pedantry, the pick-ups are 270 degrees apart, not 90!)

Ciao

Craig

As the thing works off the crank must be wasted spark. Unlike single variant turning at 1/2 crank speed.

Lots of alternative options for round case ignitions, eg DYNA,DMC, Boyer, Pazon, Silent, but for Squarecase only a few.

Rita works fine but looks ugly & consumes a fair bit of current, also obsolete.

DMC won’t work with electric start engine originally fitted with Ducati ignition. But ok for all Bosch variants.

Silent Hektik do a version for 860’s with electric start as well as all Bosch variants.

Petrol coming out the carbs? Yup, float needle or floats worn, sticking up etc. Also, the floats can get hung up if you aren’t careful putting the float bowl back on. Take it all apart, give it clean, reassemble and try again …

If you have to replace the needle, just be aware that some people have reported problems getting the new needles to seat properly. Any one had this problem recently, btw? I haven’t heard of anything for the last year or so … Maybe Dell’Orto have got over it now?

Craig
[/quote]
Hi,
There’s is another reason for the carbs to be leaking, I recently had trouble with the ‘O’ ring that seals the float chamber going hard and failing to seal on one of mine.
Another thing to look for is that the latest one piece plastic floats are larger and foul the front of the float bowl, if you fit these you need to groddle a mm away from the inside of the bowl.
It’s easy to do with a Dremmel or similar tool.

Steve R (Southern version)

Hi everyone, thanks for all the info, have sussed out the carb problem,it seems that at the bottom of the float needle assembly there should be a little washer, and guess what? Ordered a set of gasgts from euro carb along with some other bits so hopefully will be able to start her up once they arrive, fingers crossed!
Any recommendations for a basic carb setup. I have phf 32 mm cd and a type carbs and have used the settings as described in ian falloons restoration manual.Will keep you posted if I get it started, only been 6 years since i started this little project so I can wait a bit longer
cheers phil

Yes, you need to connect a 12 volt supply via ignition sw and for power transmission to the ECU you need to install the proper sensor. You can also checkout the electronics components at industrial electronics repair