diana mark 3 wiring

[hobby]

Gents
I need some advice from someone in the know. I have a Diana 250 mark 3 the model that was supplied to Berliner in the US with the 4 speed box and the tiny taillight. This bike has a two wire magneto fitted which procuses a 6V 40W output I believe and runs a 6V AC coil. This is the bike that ran the ignition system through the tail light with a small switch in case the tail light blew. Now what I want to do is the following:
1 have a LED brake light and a 12 volt horn, run of a total loss 12 v battery (all done)
2 Run the 6 volt head light and tail light of the two wire magneto
3 Run the ignition system of the 2 wire magneto also but not through the lighting system

I have only come across one Ducati wiring diagram using a two wire magneto. However this is from a RT450 and shows an AC coil (which I have in place) but from that coild also comes a wire to a item marked R in a circle which they call an ignition coil?? and then to earth. I do not have such and animal in my system.

Can anyone make up a w4ring diagram for me to suit the above please? I have attached the only wiring diagram I have as described above.
Kind regards
Paul

[Rick]

The 'R' is ruttore(Italian), your contact breaker/points assembly

[DewCatTea-Bob]

[quote= hobby ...
" I need some advice from someone in the know. "

____ That would be ME ! _ (I'm pretty-sure there's nobody-else [left] who knows more about this.)



" I have a Diana 250 mark 3 the model that was supplied to Berliner in the US with the 4 speed box and the tiny taillight. This bike has a two wire magneto fitted which procuses a 6V 40W output I believe and runs a 6V AC coil. "

____ ACTUALLY, (as it seems so far),, you must have one of the very-FIRST 'Diana Mark III' models (which was pretty-much a 250-Motocross model converted specifically just for road-raceway racing).



" This is the bike that ran the ignition system through the tail light with a small switch in case the tail light blew. "

____ NO, it is NOT ! -(Providing that your alt/mag.stator is actually the older/two-wire model.) _ As THAT Mark-III model just came with THREE wire-leads ! _ As IT needed a way to also power an added brake-light circuit.
__ The very-first Mark-III models (which had only 4-speeds), had the very-same electrical-system as that of the preexisting 250-Motocross model, with JUST two wire-leads from the alt.mag... one yellow-wire for the ign.system, and one red-wire for the head & tail lights, (but no brake-light) !



" Now what I want to do is the following:
have a LED brake light and a 12 volt horn, run of a total loss 12 v battery (all done) "

____ BUT there's no need at all to run as 'total loss' ! _ As there's a pretty-simple way to help keep the battery charged !



" Run the 6 volt head light and tail light of the two wire magneto "

____ Just simply connect the alt.mag's red-wire to the related circuit that's intended for those two lights !



" Run the ignition system of the 2 wire magneto also but not through the lighting system "

____ Not a problem,, just keep the wiring as factory-original and connect the yellow-wire directly only to the ign.circuit, (without any detour-circuit through the brake-light circuit), just as is stock for your particular/oldest Mark-III model.



" I have only come across one Ducati wiring diagram using a two wire magneto. However this is from a RT450 and shows an AC coil "

____ That schematic-diagram is pretty-much the same as meant for your old 4-speed Mark-III model !



" but from that coild also comes a wire to a item marked R in a circle which they call an ignition coil?? and then to earth.
" I do not have such and animal in my system. "

____ While working on my post here, I've come to notice that others have already clued you into this. _ (And I'll bet you surely realize that you-yourself ought-to have already realized that answer all on your-own, had you not been so hasty to get your post submitted !)



" Can anyone make up a w4ring diagram for me to suit the above please? I have attached the only wiring diagram I have as described above. "

____ I do possess a factory-diagram of the early Motocross/Mark-III wiring-scheme, however that R/T electrical-diagram should suit you well enough. _ But if you should happen to have any related questions about it, then please ask.
__ As for ALSO keeping your battery from discharging,, all you'd need to add is a couple of power-diodes, so as to separate & steer the neg & pos halves of the AC.power between the ign.system & the battery. _ That way, a significant portion of the power that's otherwise WASTED by the ign.system, can instead be utilized to keep the battery voltage-level well charged-up ! _ A real no-brainer, actually !
Let me know if you'd like more details about this simple mod.


Duke-Cheers,
-Bob

[joe46ho]

Hi, Your engine number would help, but if its an early 4 speed i cant be sure im giving you the correct diagram. I believe they used a 2 wire stator on the early 250 motocross (and also possibly the 4 speed diana) and that may even be the same stator they later used on the rt450 but i really dont know. Bob will know, we covered that in a post a long time ago i beleive. Do you know if you have the Aprilia 4521 tail light, or the really tiny cev light (this one mounts directly to the fender) If you go to the tech section there is a pdf shop manual, pg. 37 is what a early 5 speed Scr, or Diana (Both with the pancake headlight, and the Aprilia 59n bar mounted light switch) would have had from the factory. These have a 3 wire stator that is 6v-40w. If you are sure you have a two wire than this diagram will not be correct (although im sure its similar to what you have) More info would help, pictures would be better... That circled "R" in the diagram is actually your points and condensor. Im attaching a pic of pg 37 and also a link to a cad diagram that is also in the tech section that Jim made, it has a key switch added, and may be easier to understand. But again this depicts a 6v-40w 3-wire stator. Im sure someone may have a diagram of the early 250 motocross style system for you (if thats what you actually have)

http://www.motoscrubs.com/Ducati_Electrics/magneto.pdf

Joe

[machten]

Hi All,

Paul's a mate of mine and I suggested he posted his query here. For the removal of doubt...

it is an early 4 speed US 250 Diana with a two wire "magneto" and no battery...







As Bob has said, Jim's wiring diagram (even though three wire) will be close enough to set up the circuits Paul wants. There is some imperitive here to be able to easily return the bike to stock wiring - hence the somewhat "illogical" use of a total loss battery for the tail light and horn and it would be easy to fit a charging circuit into it as DCT Bob has suggested.

____ I do possess a factory-diagram of the early Motocross/Mark-III wiring-scheme, however that R/T electrical-diagram should suit you well enough. _ But if you should happen to have any related questions about it, then please ask.

Bob - if you have such a diagram for the Motocross/Mark-III wiring-scheme, it would likely be a boon to many if you were post it somewhere (tech section - motoscrubs). I have trolled the internet on quite a few occasions now, and can find no such wiring diagram anywhere. (and I'm an IT guy and know how to use search engines)

We have just rebuilt this engine to fit a kickstart and an 18 degree AAU (vs zero advance) and it is basically being set up for a Giro event in Italy for later this year. Be interesting to see how it goes when we test it, because it didn't get onto the cam under circa 4500 - 5000 rpm previously, but when it did - Hang on!

Regards,

Kev

[DewCatTea-Bob]

[quote= machten ...
" For the removal of doubt...
it is an early 4 speed US 250 Diana "

____ Actually, by merely stating just "250 Diana", you then actually add to any doubt-factor, as the 'Diana 250' was the earliest Diana-model and a considerably different Diana-version (mostly due-to engine & electrical variances), than the 'Diana Mark-III' (which is the particular Diana-model that you've posted pics of) !



" with a two wire "magneto" and no battery... "

____ Correct, (for the very-first Mark-III version of the Diana model-line), as the 'Diana 250' was the only Diana-version which actually included a battery (but, also included just a two-wire alt.mag).
__ I'm quite certain that all Mark-III Diana-models which were old enough to have their magneto-type ign.system connected-together with the old Motocross-type two-wire alt.mag, then also employed the Motocross-type headlamp (as seen in the posted-pix). _ However I'm not-sure and thusly doubtful if all Mark-III models which originally came with that Motocross-headlamp must also have included the related two-wire alt.mag, (since I suppose it's certainly possible that updated-productions of the Mark-III which still came equipped with such Motocross-type lighting-parts, later also came matched-together with the [more common] three-wire alt.mags as well, [sometime before 1964],, as I have relatively very-little personal-experience with all the specific variances of the pre-64 Mark-III model-versions, and have never seen a parts-book for those earlier Mk.III-models).



" As Bob has said, Jim's wiring diagram (even though three wire) will be close enough to set up the circuits Paul wants. "

____ Actually, I'm not the-one who stated so ! ...
It's the 450R/T's wiring-diagram which I was actually referring-to (as being "close enough") !



" There is some imperitive here to be able to easily return the bike to stock wiring - hence the somewhat "illogical" use of a total loss battery for the tail light and horn "

____ The stock-wiring AND any added wiring-mods (which I'd suggest),, are all so simple, that such concern is really not an issue.
__ Although it seems to be a waste (to me) that an installed battery would only be used for just the brake-light & horn ! _ As it could also be used to (constantly*) run a low-power headlight or something, (* if kept charged).



" and it would be easy to fit a charging circuit into it as DCT Bob has suggested. "

____ And-so why-not ? ...
A simple 3-buck bridge-block rectifier is all that would need to be added (in order to distribute the AC.power-output of the yellow-wire's [then rectified] power to BOTH the ign.system AND the battery as well) !
It's a big waste (of already generated power), to let the unused half of the AC.power to be continually dumped directly into 'ground' !



" Bob - if you have such a diagram for the Motocross/Mark-III wiring-scheme, it would likely be a boon to many if you were post it somewhere (tech section - motoscrubs). "

____ The only copy I have of that (SIMPLEST of all Ducati wiring-schemes), is a rather small diagram-depiction shown within a 1963 re-issue of a 1962-published Diana Mark-III owner's-manual.
While the particularly simple layout of all the (very few) displayed electrical-components are shown arranged somewhat differently,, 'ELECTRICALLY', the entire electrical-layout is pretty-much* the very-same as that laid-out by the 450R/T electrical-scheme diagram (as has been previously posted above) !
(* The only noteworthy difference [of the more nicely detailed R/T-diagram], is that the Mark-III's yellow-wire is rather instead labeled as "White" !)



" I have trolled the internet on quite a few occasions now, and can find no such wiring diagram anywhere. "

____ Before considering all that work, you should've asked here FIRST !
Then we ALL may've sooner been made aware of the FABULOUS-example of an early Mark-III (which YOU already knew-of).
Or have we already indeed seen this particular example posted before ? _ As I seem to recall wondering whether-if such an installed front-fender is an actual stock early Mark-III part or not,, (cuz it could possibly be, [I suppose],, that it too, [along-with the headlamp, etc.], was borrowed-over from the preexisting Motocross model-line).



" (and I'm an IT guy and know how to use search engines) "

____ Then you seem to be someone good to ask about why many search-engines will (stupidly!) round-up EXCESSIVE-results which also individually includes the finding-result for each & EVERY single solitary word entered within their search-box, all independently,, instead of JUST results which includes ONLY that of ALL the words combined & entered !?
Is there any trick to getting search-engines (such as our-own here), to find ONLY the results which you REALLY want ? _ (I've tried to interconnect the searched words with the use of hyphens [in attempt to eliminate results found for EACH independent word entered], but that otherwise useful-help is [stupidly !] unfortunately completely ignored !)



" We have just rebuilt this engine to fit a kickstart "

____ Do you mean to indicate that this particular Mark-III is such an old example, that it was never fitted with a starter-pedal from the factory ?
__ Before I-myself ever became involved with DUCATIs,, one of the very-first which I ever paid any attention to, was a 4-speed Mark-III "racing cycle" supposedly stripped-down & lightened for road-racing,, and it had no kick-start lever, so it was assumed to have been removed by the original-owner.
Could it be that ALL such early Mark-III models were imported without any starter-levers, since they were originally produced just for racing purposes ?


Duke-Cheers,
-Bob

[ducwiz]

Hi Bob,

as you know I'm not an expert in n/c singles, but always interested in their history and tech details. I just found a picture of a 1963 advert of the Berliner corp., showing the Scrambler and the Diana models. On both, the kickstart lever is clearly visible. The AC ignition is also mentioned.



cheers Hans

[hobby]

Gents I thank you all for your information thus far. It has been very helpful. I confirm that this is a very early Diana Mark 3 which was built for Berliner as a racer, but was suppose to be able to be ridden on the road also. However without the retard/advance system installed they are hard to start. As such I think the were mainly used for racing. They also lacked a brake light and only had a tail light (small) fitted with a fatsoon single filament globe. So to fit a brake light facility the only way was to install a very small led strip as there is no room for a normal globe fitting. This has now been done and works great. It's correct that a previous owner has removed the kickstarter unit, which I have now installed again.
I have original advertising material on this bike and all seems correct for that model. Including the mudguards.
I have now figured out the wiring so this weekend it's testing time to see if all works.
I choose to fit an total waste 12 volt battery to owner the brake light and horn as the led would only work on 12 volt and I had a 12 volt horn laying around. Ido not want to change the rest of the electrical system to 12 volt dc as to keep it as stock as possible. The battery is hidden under the seat as is the horn which were never fitted on this model. So it will all look stock unless you lay on the ground and look under the seat. I had a second bike the same but swapped that for an rt450. I have not seen many of these bikes and as such I think there are not many of these early models around anymore. I also understand that this model was only sold in the USA. I will report after the weekend on how she fired up and if all works ok or not.
Paul

[DewCatTea-Bob]

[quote= hobby ...
" I confirm that this is a very early Diana Mark 3 "

____ I guess you're not on-board yet concerning that the "Mark 3" did-not come to-be until the 1965 Diana-model was created... Since your 'Mark-III' was produced no later than early-1963, it MUST thus-then be a Mark III version !
Let me assure you that the Ducati-published Mark-III owner's-manual which I have (for a model-version which has the two-wire alt.mag & 4-speed trans), states 'Diana Mark III', and is actually labeled exactly THAT-way on it's front-cover, (and NOT as: "Mark 3" !) ! _ And also, the title name-term 'Mark 3' is-not found to be used anywhere within the Mark-III manual.
So please consider coming on-board with this (seemingly minor) name detail, and try referring to your older Mark-three model rather as a 'Mark-III' (instead of a 'Mark-3'). _ As I think it's fairly important for an owner such as yourself to know exactly what's-what concerning all the details of your extra-RARE Duke-model, don't you as well ?
__ It would be nice if you'd confirm at-least the first three digits of it's motor-number so we can possibly get a more-informed conception of when the original line of Mark-III models came into production compared to other Duc.single model-lines of the time-period.



" which was built for Berliner as a racer, but was suppose to be able to be ridden on the road also. "

____ Back in 1962, I then wasn't yet a decided DUCATI-guy, and-so wasn't aware of exactly what-was-what at that time when it could've been best learned-of. _ However I later heard tale that (at least) the very-first batch of Mark-III models imported by Berliner were slightly stripped-down versions of a street-worthy road-going souped-up version of an Italian-marketed Diana-250 Mark-III model. _ However at the time, Berliner just simply wanted a more straight-forward racing-version of the Diana-250 model, for selling just to those who only wanted to pay for just a more bare-bones 250-version for rather cheap & easy adaption for Road & Track racing, (much the same as the Motocross-model was meant for off-road motocross-racing).
So Ducati specially made a batch of near bare-bones Mark-IIIs to satisfy Berliner's request, and-so that first-batch was (like the original Motocross-model), not meant to be street-legal. _ So-thus those first Mark-IIIs had gotten only minimal electrical-systems, and suitably therefore were-not at all intended for public-road riding !
However not too-long after, (possibly by the very-next production-batch, or maybe not until the very-last 4-speed batch),, Ducati had adapted the 4-speed Mark-III model-line to also be street-legal (with the addition of a white-colored third alt.mag wire-lead, and the fairly well-known concocted-up brake-light circuit).
SO, it seems that the particular Mark-III model which YOU happen to have, is one of those which was originally meant for just race-use only.



" However without the retard/advance system installed they are hard to start. "

____ Actually, once ya have a good grasp of the old established understanding of the best starting-procedure for such AAU.unequipped engines, they'll start-up quite easily enough ! _ (I think Jim has learned of this for himself, maybe he'll confirm.)



" As such I think the were mainly used for racing. "

____ I'm quite certain that even some of the later street-worthy versions also came without any AAU. _ (Back then in those old-days, real-motorcyclists couldn't be pansy-types !)



" They also lacked a brake light and only had a tail light (small) fitted with a fatsoon single filament globe. "

____ That's correct, and is consistent with the road-racer version with the two-wire alt.mag !



" It's correct that a previous owner has removed the kickstarter unit, which I have now installed again. "

____ Okay,, I had thought that it may've been possible that an early batch of race-only Mark-III versions might've been produced without the inclusion of some of the kick-start parts (due-to a Berliner request).



" I have original advertising material on this bike and all seems correct for that model. Including the mudguards. "

____ That seems quite fair to deduce, since (at least) the very-first batch of Berliner-requested Mark-IIIs were merely a concoction of pre-established Diana & Motocross model parts.



" I have now figured out the wiring so this weekend it's testing time to see if all works. "

____ By "all", do you then also have a stock handlebar-switch to connect-up along-with the rest of the minimal stock wiring ?
The rest of us here only have that 450-scheme diagram you posted to consult,, so when you say you have figured-out the wiring, we're left to assume that you intend to power the taillight-filament,(LED) with the same power-source as the headlight will be powered by.
And if so, it would be of certain interest to learn of how well your tail-LED performs with the stock AC.power setup.
So could you please elaborate on this matter ?



" I choose to fit an total waste 12 volt battery to owner the brake light and horn "

____ Why would you choose to do so, when there's totally FREE alt.power to (rather simply !) be had to keep a battery charged ?



" as the led would only work on 12 volt "

____ Are you SURE about that ? _ As my-own experience with LEDs, is that LEDs meant for operating at a certain suggested voltage-range, will still work well enough even with a 50% tolerance-range. _ So you might possibly find some wiggle-room for you to work with, to come-up with another more convenient set of workings.



" Ido not want to change the rest of the electrical system to 12 volt dc as to keep it as stock as possible. "

____ I don't yet see any need for that either,, but how do you intend to control the taillight separately from the brake-light ? _ Are you intending to leave your taillight powered-on 24-7, by your battery, or what ?



" I had a second bike the same but swapped that for an rt450. "

____ (There's that universal-term "bike", being over-used by most-everyone these-days, again)... I gather that you may likely mean that you also had ANOTHER early 4-speed Mark-III, as well... (?)
If actually so, then was it newer or older ? _ How many motor-number units are the two examples separated by ?



" I have not seen many of these bikes and as such I think there are not many of these early models around anymore. "

____ No-doubt quite true, and that should make it EXTRA-valuable !
I-myself have only ever seen just one of that particular original-version Mk-III model, (just a very few times back in spring-64, with a smaller BSA-tank mounted upon it),, and I'm quite-sure that Berliner got no more than 300 like it (and pretty-sure that they only imported less than 150 such units, even-though the self-proclaimed second-owner of the particular example belonging to a near-by neighbor, claimed it was one of only-just three of such "specially made" "Ducati 'racers'" in the whole country).



" I also understand that this model was only sold in the USA. "

____ Of that I'm not really sure of either,, but it's also as well been my-own understanding that the original bare-bones Mark-III version was only made just for Berliner, and-thusly imported only into the U.S.


Dukaddy-DUKEs,
-Bob

[DewCatTea-Bob]

[quote= ducwiz ...
" as you know I'm not an expert in n/c singles, "

____ Actually, I wasn't previously aware of that,, as you've seemed to have had well-above average knowledge concerning both w-c & n-c Duke-models !



" I just found a picture of a 1963 advert of the Berliner corp., "

____ Yes, I see that,, and I-myself also have a number of old-60's cycle-mags which have very similar (if not also the very-same) page-ads contained within !
__ I note that this Berliner-ad refers-to the (pre-65) Diana Mark-III model as a "Mk 3", but this detail-error is that of Berliner's-own shortcoming and not that of the Ducati-factory itself !
I have no doubt that Berliner's "3" was substituted for the 'III' for the very-same reason as most-everyone else does... the two alternate symbols representing 'three', are simply thought-of as being readily interchangeable.
But-however in the case of the Mark-three model-line name-title, that name difference has come to represent a significant-DIFFERENCE, (which most haven't seemed to fully realize) !



" showing the Scrambler and the Diana models. On both, the kickstart lever is clearly visible. "

____ Of-course your posting-contributions are certainly always appreciated Hans, and your efforts to assist with straightening-out such matters as this, is of-course always much welcomed help,, however it seems there may've been some loss in translation here, (from my previous related post)...
__ There really wasn't any question as to whether any OTHER such Duke-models ever came produced from the factory without any kick-starter arrangement,, rather however, I had merely wondered if it was possible for just ALL of the original -(road-track racer version) type of Mark-III model-units, to have come stock without any ks.arrangement. _ Since Paul's unit as well as the only such original Mk.III version I had ever seen, both were found to be without any kick-levers.
So it was just THAT most-early Mark-III version which was actually intended to be involved with my concern about the absence of kick-starters on these rare original-version (made for U.S.) type of Mark-III models, only ! _ And not meant to also include any-other Duke-models.
__ Paul has since indicated that the kick-start pedal-lever on his-own early Mark-III, was removed by the previous-owner,, so that recent revelation has canceled my wonderment on the whole matter.
If he had not known anything about why his kick-starter wasn't found included, then I next would've continued-on and asked him about what parts seemed to be installed in place of the ks.parts. _ Because on the race-version Mark-III I had seen, not only was the foot-pedal kick-level not included,, but also the ks.shaft which it connects to, was missing as well, (with some kind of dark-colored rubber-plug placed within the hole meant for the shaft).
So I was next going to ask Paul if the setup on HIS was anything the like of such as that,, so as to determine whether it might be a stock factory-setup, or not.
However I'm now assuming that it wasn't factory-issue, as I recall the installed plug wasn't looking very oil-tight.
____ Thanks anyhow Hans !



" The AC ignition is also mentioned. "

____ Yes, in other-words -("magneto"), I see that indeed it is ! ...
Back in those days,, whether a motorcycle had magneto-type ignition, was a fairly major selling-point, as it was then well assumed that magneto-ignition was universally-considered to be a greater performing ign.system which helped make cycle-engines run stronger & faster. _ And no-doubt that's why Berliner bothered to mentioned so within their ad-hype.
__ Anyhow however,, as you must already know Hans, that type of ign.spark-production is not-really powered by 'AC',, but rather, by just a DC.component of the generated & applied raw AC, (of which the vast majority of the generated AC.power is normally unfortunately wasted) !


____ At this point, I probably ought-to once-again remind readers that much of my post-writings are-not always actually meant to at-all address the member who's post-wording I've quoted,, but rather, the quoted-wording I've chosen is merely used as a springboard for the thusly motivated post-response which I care to detail for OTHERS to take-in & digest.


Duke-Cheers,
-Bob