Adding headlight and tail light - best way

[DewCatTea-Bob]

[quote= JimF ...
" I believe this is because your electrical system uses unregulated AC voltage. "

____ We ought be clear as to whether we're in reference to "fluctuation" or mere 'flickering' of the light,, as while regulated power-peaks would indeed subdue otherwise notable light-flickering, the fluctuation would still remain noticeable between high & very-low RPMs as actual power-production varies -('fluctuates') in power-strength. - (As of-course it certainly must be realized that 'regulation' [alone, without a battery], can't possibly make-up for insufficient power when the 'fluctuation' has fallen to it's downward level !)



" you must accept that your electrical system is weak. Bob will argue how weak, "

____ How "weak", is a RELATIVE term ! ...
The stock electrical-power is actually quite adequate for the originally intended load-system, and therefore not-really "weak" ! _ It's only fair to say it's 'weak' when compared to modern over-powered systems (which usually have-not been balanced [and therefore consequently require a regulation-circuit] ).
__ In-fact, it could just as well be argued that Ducati's power-system is rather strong,, cuz it actually has the capability to sufficiently power a fairly greater load-system than stock !



" Ducati rated your system at 40 watts of power and if we accept that number remember that the 40 watts has to serve the headlight, the brake light, running light and the ignition system "

___ It's hard-saying exactly how Ducati happened to come-up with an even "40-watts" rating for their 4-pole alternators, but it sort-of seems fairly obvious that they rated them as such because their alt.stator-coils (at-least) met the requirements of the employed loads of the intended electrical-system. ...
__ The lighting-coil (of the alt.stator) quite-fairly adequately powers-up a 25-watt headlight & a 3-watt taillight (both at once),, and-so that of-course CERTAINLY evidently means that that power-coil alone is logically accountable for at-least 28-watts total, all on it's own & all by ITSELF !
And if we apply Jim's-own logical-reasoning to the whole alt.mag,, then that would have-to mean that the pair of power-coils together, should be good for (at-least) 56-watts total (instead of merely-just "40") !
That Ducati quite-obviously rounded-off the power-total 'rating' to just 40-watts,, indicates to me, that they only expected their ignition/brk.light-circuit to just consume only about 12-watts (difference) from the ign.power-coil,, (thus leaving to waste over 16-watts of alt.power [through the grounded-ign.points, (when the brk.light is-not activated)]!).
So as could-be logically deduced,, Ducati must have figured that the ignition-coil (and-also the ign.coil in series with the brake-light), consumes between 10.5 to 13.5 watts, and-so added the other 28 watts to that amount so as to come-up with a rounded-figure of an even '40-watts' total, for somewhat fairly 'rating' their 4-pole alt.mag-unit. _ And-thus, Ducati must-not have rated their alt.mag-unit according to it's maximum possible wattage-output,, or-else it would've rather been rated considerably higher -(at-least 56-watts !), than their even 40-watt rating !
(I think Jim should now finally realize the validity of this logical-reasoning, and finally discontinue always presuming that each of the two power-coils simply only produce just an even 20-watts a piece, [as he has pretty-much always previously done].)



" I would keep the ignition circuit AC. "

____ There's indeed certain benefit to retaining the magneto-type ET.ignition-system,, however it need-not be left 'AC' supplied, as that just leads to power-WASTE and extra unnecessary heating of the connected power-coil !



" you should regulate the DC so that you don't over-voltage the LED components and destroy them. "

____ With BALANCED power & load systems, (such as Ducati usually intended),, 'regulation' is-not actually required ! _ As a standard battery will then tend to quite-adequately absorb any leftover peaks and fill-in the valleys (which are both relatively slight within such basically 'balanced-systems') !
And the 30/20w LED-bulb under consideration, is quite close-enough to the expected wattage-output of a single power-coil, (and-thus would tend to maintain a rather balanced-state, much the same as stock) !


Dukaddy-DUKEs,
DCT-Bob

[STEVENM63]

Interesting. White and green wires show continuity at 1 ohm. All three wires have continuity to ground. Now I'm concerned how this bike was put together.

[DewCatTea-Bob]

[quote= STEVENM63 ...
" White and green wires show continuity at 1 ohm. "

____ The resistance-level for the IGNITION power-coil should actually be about .9-ohm, so that revelation is about as expected.



" All three wires have continuity to ground. "

____ Considering your Duke-model's model-year -("65") which you've indicated (you believe) you have,, that would mean that either the 40w.stator has an ign.power-coil circuit that's become short-circuited to ground, or-else somebody has purposely modified it's stator-wiring in some way (for some kind of customized circuitry).
However, I'm now thinking that the green-wire was-not actually randomly-chosen (to replace the stock yellow-wire), as that particular color has possible logical-reasoning for it's choice as a replacement-wire. ...
__ It now seems more likely that your alt/mag.model is-not the '40-watt' version, but-rather the so-called '28-watt' version. _ As that particular alt/mag.model rather has all-three of it's wire-leads connected to grounded power-coil circuits (and-so would all indicate continuity to ground) !
(And, the particular wiring-system on stock Duke-models which employ the 28w.model, happen to have green-wiring for all their other ignition related circuits, [so-thus the green replacement-wire actually makes better logical-sense to have chosen for the ign.power-coil] !)
__ To confirm that my greatest-suspicion is actually correct,, you need to set your ohm-meter to it's most sensitive setting (for accurate measurements under 1-ohm), and test for ohm-readings of all three wires' resistance-levels to ground.
I'd then expect ohm-readings within the following ranges... red-wire = .4 to .7 ohm; white-wire = .1 to .3 ohm; & green/-/yellow-wire = .7 to 1 ohm.
__ If those ohmic-values are indeed found,, then it's rather likely that your 250-Duke is actually a 1966 Scrambler-model
(which rather employs the '28-watt' alt/mag.model, instead of the older '40-watt' version).



" Now I'm concerned how this bike was put together. "

____ Do you mean by a previous-owner ?
__ To help determine if the internal alt.stator-wiring was customized by a PO., or if you more likely have a rather stock 28w.alt/mag.model,, then let me know at-least what the first three digits of the motor's (DM250 -) 'motor-number' are, and then I can confirm whether your motor should have a '28-watt' alt/mag.model or not.
Also, a picture of your frame's battery mounting-plate (area in front of the rear-fender), would also be helpful to determine what Duke-model you actually have.


Hopeful-Cheers,
DCT-Bob

[STEVENM63]

Okay, here are my readings.
White = 1.0
Red = 0.4
Green = 0.1-0.3

Engine serial # 964...

Based on your comments above Bob, the ignition should be hooked up to my white wire, not the red wire as it currently is. Should my next, non scientific, step be to hook up the white wire to the ignition and see if the bike runs?

[DewCatTea-Bob]

[quote= STEVENM63 ...
" here are my readings.
White = 1.0
Red = 0.4
Green = 0.1-0.3 "

____ The readings themselves, (assumed singularly taken between each of the three wires and ground), confirm that your alt/mag.model is indeed the '28-watt' version !
However as it turns-out, (providing you haven't made any error),, the white and green wire-colors are obviously rather randomly connected to the stator, (and now I guess the green-wire was-not logically chosen after-all).
__ What really CONFIRMS that your alt/mag.model is the 28-watt version, (and most-likely not an altered 40w.model),, is it's near .2-ohm resistance-level, which is unique for the 28w.model (as it's added circuit for charging a 6v.battery [which the 1966-Scr.model got updated for dealing with the rather poor factory-rigged brake-light circuit of the 1965-model] ).



" Engine serial # 964... "

____ That motor-number definitely-indicates that your 250-motor is of a 1966 model-year ! _ And since it has a 28-watt alt/mag.model, that indicates your Duke-model as being a '250-Scrambler' !



" Based on your comments above Bob, the ignition should be hooked up to my white wire, not the red wire as it currently is. "

____ That's a correct deduction ! _ As your "1.0" ohm-reading indicates that the white-wire is connected to the IGN.power-coil.
__ Also, your "0.4" ohm-reading is collaborative for being connected to the lighting power-coil and rather intended for the main-lights ! - (And-thus leaving me wondering if that red-colored wire was purposely used [as stock] or also randomly chosen & installed.)



" Should my next,
step be to hook up the white wire to the ignition and see if the bike runs? "

____ Well, while I wouldn't really depend on that step to assuredly allow you to see if the bike runs,, I would however expect that that next-step would indeed be advisable for confirming that the ENGINE can still start-up & run ! - (And rather without any concern of over-heating the connected power-coil [which was designed to be short-circuited most of the time (when the ign.points are closed)]!)


____ Do you currently have any headlight-bulb to try-out with the red-wire's power-output ?
__ Now after all this latest info.revelation, please let us know what-all you're now thinking next.


Hopeful-Cheers,
-Bob

[STEVENM63]

Okay, I wanted to provide an update. After resolving my carburetion issue, I'm back to electrical troubleshooting. So I reconfigured the ignition wiring based on the findings above (my white wire being the equivalent of the original yellow wire based on the ohm reading). If you recall, the ignition was originally connected to the red wire on my bike. After rewiring, I checked the new configuration for spark and I confirmed that I had spark. With the new configuration, I attempted to start the bike but I was unsuccessful. Since the bike had started before with my red wire connected to the engine, I reconnected it to the the ignition and the bike started right up. I tried the same test again this morning and got the same result (no start on the white wire, but started with the red). I took the bike for a short run around the neighborhood and it ran well (while connected to the red wire).

So I guess now I am even more confused. Is it possible to have spark from the white (1.0 ohm) wire but something have something else wrong which would cause the bike not to fire?

[DewCatTea-Bob]

[quote= STEVENM63 ...
" I tried the same test again this morning and got the same result (no start on the white wire, but started with the red). "

____ Well of-course that's pretty-strange !
Originally the stock white-wire provided just a rather slight amount of power-juice for merely trickle-charging the battery and-so wouldn't be strong enough to power the main-lights or make a useful ign.spark ! _ So of-course it seems fairly stupid for someone to have changed the original white-wire's circuit to any other wire-color ! _ So rather than have done such an illogical change, it seems more likely (from my point of view) that you may've somehow mixed-up your notes on which wire-color actually had your near 1-ohm reading and which one had the near .2-ohm reading.
So could you double-check that you actually had all your related notes all kept in correct-order,, and also, try-out connecting-up the other other-wire -(green-wire) to see if that-one provides any useful ign.spark or not.



" Is it possible to have spark from the white (1.0 ohm) wire but something have something else wrong which would cause the bike not to fire? "

____ Well, while it seems sort-of unlikely to have anything to do with the bike firing or not,, it-is possibly possible that (like many other newbies), you may've wrongly connected-up the mag.coil wire to the ignition-coil rather in 'series' with the ign.points (like battery-powered ign.systems are wired), instead of properly connected-up in 'parallel', as your magneto-type ign.system is supposed to be connected with the ign.points.
__ So have you ever checked-through that other related thread (which I gave you a link to), to see that you have your ign.coil circuit properly hooked-up (as Ducati intended) ?
____ What gap-size do you have your spark-plug set at ? _ Cuz that's another possible issue that could be off-kilter, (as the ign.power-coil's power-production may be too weak to create a powerful enough spark [at kicking-speed], if the plug-gap is set too wide). _ If the s.gap is set too wide, then the engine may need to be push-started, (as push-starting speeds will turn-over the engine at rotor-RPMs higher enough to create enough power-juice for the ign.system to create a sufficient spark across larger s.gaps [than are factory-recommended for Ducati's magneto-type ign.system] ).

____ Let us know what-all you find-out next.


Hopeful-Cheers,
-Bob

[STEVENM63]

Here are the readings for the red and white wires. Green wire from the magneto isn't hooked up to anything. The bike starts and runs when the red wire from the magneto is connected to the kill switch. When the white wire is swapped with the red wire and connected to the kill switch, the bike will not start. I do show spark when either the red or white is connected. Spark plug gap is .27.

Thanks for you help.

Steven M

[DewCatTea-Bob]

[quote= STEVENM63 ...
" Here are the readings for the red and white wires. "

____ They are both within the expected normal-range, (although rather ought be closer to .8 ~.9 & .5 ~.6 [rather than the presented '1.0' & '.4' ohm-readings]).



" Green wire from the magneto isn't hooked up to anything. "

____ That coil-circuit should be for the factory-intended bat.charging-circuit.
It would be of interest to see if it also could possibly be capable of producing a spark (when rather connected-up to the ign.circuit).



" The bike starts and runs when the red wire from the magneto is connected to the kill switch. "

____ Although probably not really related to your issue,, according to your scheme-diagram, your "kill switch" is rather connected-up as an On/Off-switch and not as a standard 'kill-button' !
I've re-posted your scheme-drawing with modifications indicating a proper std.KILL-circuit.
__ The reason the lighting-coil is more easily starting the engine, is likely because it develops more power-juice at lower kicking-speeds, and-so better deals with whatever impeding issue is the cause of your lack of starting success with the correct power-coil. ...
Besides related spark-plug issues, I'm wondering if your ignition-coil is-not the stock 'green-label' version ? _ You don't have some-other non-stock ign.coil installed in place, do you ?? _ Cuz if-so, then there's a possible chance that it's 'impedance' is-not well matched with that of the ign.power-coil.



" When the white wire is swapped with the red wire and connected to the kill switch, the bike will not start. "

____ Do you mean that the engine will-not fire-up by 'kick-starting' ?
__ Have you ever yet tried 'push-starting' your Duke (with the ign.power-coil connected-up [rather than with the lighting-coil] ) ?



" I do show spark when either the red or white is connected. "

____ Doesn't the 'spark' appear any different in strength -(color-brightness; zap-report intensity, etc) between those two different connect-ups ?



" Spark plug gap is .27. "

____ Where did you get the notion to set the s.gap at that amount ?
As I think I recall, that amount of gap-space is rather within the spec.range intended for the BATTERY-powered ign.systems,
whereas the s.gap range intended for mag.powered-systems is between .017~.021" .
So try reducing your s.plug's gap down-to .016~.019" and see if that then allows for sufficient kick-starting, (and please let us know how it goes for you).



" Excuse my crude diagram "

____ It's certainly better than none, and even better than some others I've seen submitted.
__ It does properly indicate the PARALLEL-arrangement of the ign.coil & ign.points (as is factory-intended for Ducati's magneto-type ET.ignition-system) !


Hopeful-Cheers,
-Bob

[STEVENM63]

[quote= STEVENM63 ...
" Here are the readings for the red and white wires. "

____ They are both within the expected normal-range, (although rather ought be closer to .8 ~.9 & .5 ~.6 [rather than the presented '1.0' & '.4' ohm-readings]).



" Green wire from the magneto isn't hooked up to anything. "

____ That coil-circuit should be for the factory-intended bat.charging-circuit.
It would be of interest to see if it also could possibly be capable of producing a spark (when rather connected-up to the ign.circuit).



" The bike starts and runs when the red wire from the magneto is connected to the kill switch. "

____ Although probably not really related to your issue,, according to your scheme-diagram, your "kill switch" is rather connected-up as an On/Off-switch and not as a standard 'kill-button' !
I've re-posted your scheme-drawing with modifications indicating a proper std.KILL-circuit.
__ The reason the lighting-coil is more easily starting the engine, is likely because it develops more power-juice at lower kicking-speeds, and-so better deals with whatever impeding issue is the cause of your lack of starting success with the correct power-coil. ...
Besides related spark-plug issues, I'm wondering if your ignition-coil is-not the stock 'green-label' version ? _ You don't have some-other non-stock ign.coil installed in place, do you ?? _ Cuz if-so, then there's a possible chance that it's 'impedance' is-not well matched with that of the ign.power-coil.



" When the white wire is swapped with the red wire and connected to the kill switch, the bike will not start. "

____ Do you mean that the engine will-not fire-up by 'kick-starting' ?
__ Have you ever yet tried 'push-starting' your Duke (with the ign.power-coil connected-up [rather than with the lighting-coil] ) ?



" I do show spark when either the red or white is connected. "

____ Doesn't the 'spark' appear any different in strength -(color-brightness; zap-report intensity, etc) between those two different connect-ups ?



" Spark plug gap is .27. "

____ Where did you get the notion to set the s.gap at that amount ?
As I think I recall, that amount of gap-space is rather within the spec.range intended for the BATTERY-powered ign.systems,
whereas the s.gap range intended for mag.powered-systems is between .017~.021" .
So try reducing your s.plug's gap down-to .016~.019" and see if that then allows for sufficient kick-starting, (and please let us know how it goes for you).



" Excuse my crude diagram "

____ It's certainly better than none, and even better than some others I've seen submitted.
__ It does properly indicate the PARALLEL-arrangement of the ign.coil & ign.points (as is factory-intended for Ducati's magneto-type ET.ignition-system) !


Hopeful-Cheers,
-Bob

Okay, here is the latest. I changed the spark gap to .018. With the red wire (lighting) attached the bike easily started after a few kicks and ran. I did a loop around the neighborhood to warm the engine. I then came back and changed to the white (ignition) wire and with the warmed engine I tried to kick start and push start. The most I got was a couple of combustion "pops", but the engine wouldn't fire and run. It appears that whoever wired the bike this way must have done so because of this condition.

So based on these findings what would you suggest? Do I need to dig into the ign.coil?