mcman56 Posted October 20, 2017 Report Share Posted October 20, 2017 Several places sell universal regulator/ rectifiers. Maybe if the stator wire connected to the CDI and one of those it could work. The people that sell them should know so it may be worth an email to ask. https://www.bajadesigns.com/products/regulator-rectifier-dc-unwired.asp http://www.rickystator.com/product/other-parts/item/regulator-rectifier-w-relay https://www.denniskirk.com/2001630.sku?utm_source=google&utm_medium=cse&gclid=EAIaIQobChMIxoH3i5T-1gIVDp1-Ch2SaAMlEAQYCCABEgIzdfD_BwE&ad=45713338237 Quote Link to comment Share on other sites More sharing options...
caleb93 Posted October 20, 2017 Author Report Share Posted October 20, 2017 mcman that is exactly what I have tried to do with limited success. I had a few different rectifiers and regulators laying around and I played with all of them. The issue is when I hook up any the rectifiers it either shorts the AC side or drops the voltage too low to make a spark i'm really not sure why it is not working. I have wondered if its an issue that both the trigger coil and I guess power coil (I forgot the real name as of now) as well as the dc circuit all share the same ground but once again I really have no idea. Ducati made it work somehow so onward I experiment! So the next thing I am going to try is to put resistors off the yellow wire, i'm thinking about 150 ohms+ to keep the wattage down and essentially keep the AC voltage high and "separate" the DC circuit enough that I can regulate the voltage down on the DC side. I have doubts however because the voltage drop across the resistor is going to be severe in theory according to ohms law but its just on paper so maybe. Just maybe. I'll post back with results probably tomorrow so hopefully I stumble across some sort of success. Quote Link to comment Share on other sites More sharing options...
mcman56 Posted October 20, 2017 Report Share Posted October 20, 2017 Voltage dividers drop voltage. If you knew the true output at idle, you could step that down to 12 volts or so for the fan and let the AC regulator maintain it down there above idle. I have been playing with a Rev3 ignition and I get 182 volts from the stator going to the CDI and 16 volts from the stator going the the lights/ fan at 670 RPM. This is with a scope but my skills are pretty limited. https://learn.sparkfun.com/tutorials/voltage-dividers Quote Link to comment Share on other sites More sharing options...
caleb93 Posted October 20, 2017 Author Report Share Posted October 20, 2017 So i'll bet my CDI wants similar voltage and everything else definitely doesn't want the 150+ voltage. I think that your voltage divider is the answer! According to your page I should use a 1000 ohm resistor and seperate the voltage out and then a 400ish resistor after that to ground. With the impedance so high they shouldn't waste much power by turning it into heat and I think the two resistors will solve my voltage drop! Thanks for checking the voltage on your own bike it makes me think the CDI wants real high AC voltage which its getting anyways. I think this is the answer but we will see tonight. Quote Link to comment Share on other sites More sharing options...
caleb93 Posted October 24, 2017 Author Report Share Posted October 24, 2017 Well the update has bad news. I have more information but possibly made more questions. I tried the voltage divider with little success. I had basically the same success wiring in a voltage divider vs just a resistor. I made a wiring diagram to more clearly show what I did. What I've done is unplug the "faulty regulator" and jump between the two yellow wires as shown in the diagram. I then pull off the big yellow wire and run a few 25 watt resistors in series to a total of 55 Ohms. I came up with this number because the higher the ohms the less voltage would come out the other side and the fan wouldn't run. This was the comprise I felt was what I could do with the fan still working and the resistors dissipating anywhere between roughly 18 to 125 watts. I felt this was "safe" because its only going to use 125 Watts plus at very high revs which the bike never really goes to, and the stator should safely produce 75 watts of continuous power as that's what my lights option draws. Additionally I used different values of resistors so if the power dissipated exceed 75 watts one of them would burn up saving the stator. After the resistors I run the power through a diode to make some half rectified DC to run the fan. The voltage coming out of the DC side was roughly 5-10 V DC. I ran the bike like this partly because I was itching to ride and partly to see how it works and ran. It seemed to do so fine, it never missed and the fan came on and ran like it should just a bit slower then it ought to because of the low voltage. It is an inefficient use of power as it heats the resistors a bunch but it seemed crude. The problem came when I started to have too much fun and went OTB. I got up bike still running and killed it with the switch. I recollected myself and went to start it and nothing. I couldn't do anything to get it to start. I pushed home and verified all of my wiring being still good. The stator ohmed out the same and the voltage produced was the same, along with the pickup coil which just leaves my CDI and coil as the problem. This leaves me with two possibilities of whats happened. Either the CDI actually wants regulated AC to a degree from the stator and since mine was not strictly regulated it very well could have burned up the CDI and coil. The other option is the CDI and coil was what was going bad in the first place and I just finished it off with my trashy riding skills. I can argue for either because my regulator never did have the burning or any signs that it got too hot, but it is very possible and honestly very likely that I burned up the CDI with all my messing about. I am unsure as to how I am going to proceed, I would like to find at least something helpful to keep these trashy systems alive because the options to replace them are drying up. I am going to talk to Jim again, he is the man with the answers. If I come up with something useful I will post back at least there is a bit information out there now. Quote Link to comment Share on other sites More sharing options...
mcman56 Posted October 24, 2017 Report Share Posted October 24, 2017 It sounds like we need an electrical engineer to step in. There should be some way to isolate a line to the fan from the line to the CDI. Do you know if your CDI provides a spark advance curve? Some do and some don't. I checked a 97 Techno and it provided about 25 degrees of advance between idle and max revs. My 2008 Rev 3 only provides about 5 degrees and from my understanding that is from things happening a little quicker at higher voltages and not due to designed in advance. Looking at earlier Rev 3 stators, they have two trigger coils so must have one for idle and one for higher rpms. Many older street bikes do that. Anyway, I have heard of TLR200 owners running pit bike CDIs on their bikes because the Honda ones are no longer available. The only issue is no advance curve or unknown advance curve. http://www.classictrial.co.uk/hondacdi.html Of course, this does not help with the fan issue. A sort of crude way to keep riding while working on this would be to run the fan with a small battery. Quote Link to comment Share on other sites More sharing options...
caleb93 Posted October 25, 2017 Author Report Share Posted October 25, 2017 I agree! However I really don't know how many of the Ducati systems are still alive today or how well people are getting along with them. I don't know if it advances the spark or not. I am not sure if there is any way to tell other than when it is running. If I get it going again I'll put a timing light on it and see what comes from it. I am considering trying to find a different CDI and coil and seeing if I can make something else work. I do have an old XR 200 AC CDI and coil laying around so maybe I'll hook it up and see what happens! I did consider running a battery but my resistors did work arguably better than a battery but its still not the right fix for the thing. Quote Link to comment Share on other sites More sharing options...
caleb93 Posted December 15, 2017 Author Report Share Posted December 15, 2017 (edited) I figured I should update this to potentially help anyone else who may have similar issues. Unfortunately the correct fix is what sectionone mentioned in the beginning which is to somehow find a used kokusan ignition from another pro. This is what I have done and its been great for a month and a half so far. I am more convinced now that the CDI does want unregulated high AC voltage from the stator, that is how both the kokusan and hydria (and a lot of other systems) work. However, if someone is more brave than I and wants to mess with this more, I was thinking of finding a small transformer to step the voltage down and effectively isolate the high voltage for the CDI down from the lower voltage that way I would have been able to regulate and rectify power for the fan. I have no idea if this would work but that was what I was going to try next until I was able to score a kokusan. I did have another plan to get the new Hydria stator, flywheel and CDI which is readily available but the wiring harness is not available. That means I would have had to make my own harness which should not be a big deal except for the plug into the CDI. Someone would either have to find something that fits or make something that would work. Then you would have to figure out which wires go to which on the CDI. IF somehow all that worked then the normal ignition coil, fan regulator and AC regulator could work. This option is very desperate and I would have only done it if I was unable to find a used system but I believe it could work (the stator and flywheel will still bolt up to an older bike), with lots of work and head scratching. I hope this helps anyone with a Ducati system because I believe the black plug regulators are gone but Jim Snell does have some blue plug regulators as of now. Edited December 16, 2017 by caleb93 Quote Link to comment Share on other sites More sharing options...
sectionone Posted December 15, 2017 Report Share Posted December 15, 2017 The Kokusan swap is the best solution and mine has been working fine for a year and a have since I stopped using Ducati. Except this summer the rectifier went out, another cursed Italian part. I replaced it with this: https://www.ebay.com/itm/TRIUMPH-NORTON-BSA-ROYAL-ENFIELD-ETC-SOLID-STATE-RECTIFIER-PN-99-9882-/401454218290?hash=item5d78893c32 I'm concerned about exposing electronics to heat so I mounted the CDI on the left side behind the radiator, next to the fan and added cooling fins on the rectifier and mounted it behind the numberplate. Not so worried about the coil so it is behind the steering head. Quote Link to comment Share on other sites More sharing options...
caleb93 Posted December 16, 2017 Author Report Share Posted December 16, 2017 Have you got a picture of what you have done? I fit everything behind the steering head and it is an unsightly rat nest with no issues yet but it is winter though... Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted December 16, 2017 Report Share Posted December 16, 2017 On 20/10/2017 at 2:29 AM, michael_t said: too bad Jim got kicked off this site but he does post on ADV rider in the trials section so you could try posting your question there. He broke the rules, so it was his own fault. Quote Link to comment Share on other sites More sharing options...
michael_t Posted December 18, 2017 Report Share Posted December 18, 2017 (edited) On 12/16/2017 at 0:13 PM, nigel dabster said: He broke the rules, so it was his own fault. still too bad ... as he is a great resource to answer these sorts of questions when allowed. Just glad he hasn't been kicked off other sites. When you think of all of the videos he has created and free technical advice over the years to support the maintenance of trials bikes it can really only be seen as a loss to this forum in the bigger scheme of things... but hey rules are rules. I guess it isn't an issue posting diagrams that he has created such as the one above "rising sun" was his company after all. Edited December 18, 2017 by michael_t Quote Link to comment Share on other sites More sharing options...
sectionone Posted December 18, 2017 Report Share Posted December 18, 2017 On 12/15/2017 at 7:45 PM, caleb93 said: Have you got a picture of what you have done? I fit everything behind the steering head and it is an unsightly rat nest with no issues yet but it is winter though... 20171218_170129 It is attached with foam tape and a zip tie on an aluminum radiator guard I made. 20171218_170141 The rectifier with a heat sink epoxied on. Quote Link to comment Share on other sites More sharing options...
caleb93 Posted December 19, 2017 Author Report Share Posted December 19, 2017 Should dissipate heat well. Are you ever worried about hitting the CDI? Thanks for sharing what you have done! Quote Link to comment Share on other sites More sharing options...
sectionone Posted December 19, 2017 Report Share Posted December 19, 2017 My radiator guard extends beyond the surface of the cdi and the cdi is not securely mounted. Sort of a breakaway mounting. I plan on making a plastic cover for it. The new Betas, Sherco, Scorpas have the cdi mounted exposed in a lower position which might be better but a mounting bracket needs to be made. They have been doing this for a few years now and maybe it is to keep it cooler but it looks to be in a vulnerable spot. Quote Link to comment Share on other sites More sharing options...
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