petorius Posted January 24, 2018 Report Share Posted January 24, 2018 Okay, so this is not really trials related but I suspect someone on here will be able to offer some advice. I have a Bultaco, Pursang which I have been building and is pretty much all done, however I cannot get a spark from the Motoplat ignition. The ignition is the internal rotor type 63mm rather than the external rotor trials type. I have taken some measurements and referenced them, the coil and stator both seem to throw odd values. I have tried contacting UK Motoplat both via website and Ebay listing but no reply has been received. I have also tried West Country windings who tell me they cannot repair Motoplat. Does anyone know anyone in the UK that could check and repair the ignition or suggest a good (economical) replacement? I do have an external rotor Motoplat but the crank taper is different and will not fit. Coil (Red lead type) Large terminal to small terminal 35.5Ω Large terminal to ground plate – Small terminal to ground plate – HT lead to ground plate – Stator (Diode symbol embossed) Blue lead to black lead 10.7Ω Blue lead to ground plate 128.6Ω Black lead to ground plate 142.5Ω Thanks Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 24, 2018 Report Share Posted January 24, 2018 Ahh Motoplat issues, and the Pursang (my guess) is probably an electronic one, which are very complicated to repair (like the units completly cast in plastic for the Beta TR34)? Sorry you have to Name the model and also sent a Picture to which Motoplat you are referring. A good if not the very best ressource I know to any Motoplat ignition problems is Ewald Rosner an electric engineer in Austriua. His side dedicated to motorcycle ignition you find here: http://www.motelek.net/ His site is in German but he provides all information for free, the best way to solve problems with Motoplat or ny ignition is to call him up, his number is written down there. He repaired the Motoplat ignition unit to my Beta TR34 in a couple of days, he took just the money he need for the spare and repair surplus a bit as a donor to run the site. I very highly redcommend his technical skills and solutions, as he is a super professional engineer but you have to call no e-mail will be answered. He also gives out repair manuals on his site to several Motoplat ignitions you can translate them online in English which might also help: https://translate.google.de/translate?sl=de&tl=en&js=y&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.motelek.net%2F&edit-text=&act=url The Information he provides is free of use. To use his information to gain money or to try to sell them elsewhere is prohibited. 1 Quote Link to comment Share on other sites More sharing options...
petorius Posted January 24, 2018 Author Report Share Posted January 24, 2018 Thanks for that pschrauber, i will look through. Do you know how his English is? The ignition is electronic, attached photos. I know there are lights fitted on the bike but there is no lighting coil on the ignition but was planning to a separate total loss with LED bulbs as the would hardly be used. 1 Quote Link to comment Share on other sites More sharing options...
stevem75 Posted January 24, 2018 Report Share Posted January 24, 2018 I’ve seen this with motoplat before. The resistance values seem about right but I’m not 100% sure. But the real issue isn’t with the resistance of the windings within the sealed coil block. It’s the capacitor that stores the electrical charge. As the flywheel spins it induces ac electrical voltage within the winding. That voltage generated is to be stored in the capacitor until another trigger type coil fires and tells the capacitor to shunt it’s current to ground (or in this case an ignition coil) I’d bet if you are able to actually spin the engine up fast enough you’d probably generate spark because you are able to create enough stored energy in the capacitor to make the system work. Problem is it won’t last. The capacitor is worn out. The coating around it is allowing current to leak out. This is why it won’t work. There are several places worldwide that can repair motoplats. A google search can turn them up. This is a common problem with older electronic equipment. And usually is easily and permanently fixed. Ironically the best best preventive maintenance for this problem is to ride more !!! That’s right the more use the electronics get the longer they will last. Steve Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 24, 2018 Report Share Posted January 24, 2018 I don't think it has to do anything with capacitaors, These are regulary just mounted to point's ignition to cut off voltage peaks generated by the points so they don't burn themself away while operating. It's an electronic ignition, so there won't be any capacitaors, instead thrysistors wich are well cast inside the coil with also have electronics inside. See here: http://www.motelek.net/zundanlagen/motoplat2.html I would discuss this issue with Ewald, and to his English I don't know but think he can speak some English at least, try to keep sentence simple and short, I would too suggest to speak slow and pronounce well then it should be hopefully not too dificult. Oh and he has an heavy Austrian dialect this will have an impact in his English speech too... Quote Link to comment Share on other sites More sharing options...
petert Posted January 24, 2018 Report Share Posted January 24, 2018 Bradford Ignitions down in Cornwall Quote Link to comment Share on other sites More sharing options...
stevem75 Posted January 24, 2018 Report Share Posted January 24, 2018 Yes a thyristor will be used to trigger the voltage collapse of the capacitor. This is why this type of ignition is often referred to as capacitive discharge or CDI. There has to be a storage device of some sort in order for the system to work. Trust me it uses a capacitor that right now isn’t storing energy. Steve Quote Link to comment Share on other sites More sharing options...
thall1 Posted January 24, 2018 Report Share Posted January 24, 2018 from memory Steve at Bradford Ignitions, (uk Motoplat) Cornwall, doesn't work full times so you may need to try a few times Quote Link to comment Share on other sites More sharing options...
bult360 Posted January 24, 2018 Report Share Posted January 24, 2018 2 hours ago, petorius said: Thanks for that pschrauber, i will look through. Do you know how his English is? The ignition is electronic, attached photos. I know there are lights fitted on the bike but there is no lighting coil on the ignition but was planning to a separate total loss with LED bulbs as the would hardly be used. Love the bike , looks like a model 167 mk9 if its a 250 ,with a Frontera tank, is the front end Honda with the disc brake ? .Very nice indeed Quote Link to comment Share on other sites More sharing options...
petorius Posted January 24, 2018 Author Report Share Posted January 24, 2018 Thanks for all your comments, Bradford ignitions (UK Motoplat) was who i was banking on. Bult, you know your stuff, actually a 168 frame but it is Pursang mk9 , forks are modified KX cartridge , KTM wheel, Nissan caliper (thought it would be a good idea to have one brake that worked!). Just want to get the thing running and sell it. It has taken a while to get together and i have lost interest somewhat. Cannot really see me using now. I have a Sherpa/Alpina in the garage waiting for me to decide whether to end up trials or trail (keep changing my mind), which would probably be more use. 1 Quote Link to comment Share on other sites More sharing options...
scifi Posted January 25, 2018 Report Share Posted January 25, 2018 Looks like a nice bike, but if you removed the lights, and got a replacement electronic ignition, you could use it at Classic Scrambles events. . Quote Link to comment Share on other sites More sharing options...
dadof2 Posted January 25, 2018 Report Share Posted January 25, 2018 What Stevem75 says about capacitors in CDI ignitions is right but I do not think the motoplat is a CDI type. I think it is electronically (transistor) switched, but in other respects the same as a conventional points switched system. Try PVL ignitions or Karting ignition suppliers. Quote Link to comment Share on other sites More sharing options...
Miker Posted October 7, 2020 Report Share Posted October 7, 2020 Hi Petorius , I just bought this bike from the guys that you sold it to . They said that it will start and ride but I hav`nt got a spark from the plug . Did you get it fixed in the end ? I love the bike but just need to get it started . Quote Link to comment Share on other sites More sharing options...
pschrauber Posted October 10, 2020 Report Share Posted October 10, 2020 On 1/25/2018 at 4:44 PM, dadof2 said: What Stevem75 says about capacitors in CDI ignitions is right but I do not think the motoplat is a CDI type. I think it is electronically (transistor) switched, but in other respects the same as a conventional points switched system. Try PVL ignitions or Karting ignition suppliers. Yes that id right, Motoplat uses transistors and these do fail, sorry for my late reply but I wanted to make that sure as I have come to likewise problems to other ignitions. Quote Link to comment Share on other sites More sharing options...
larry s. k. Posted November 3, 2020 Report Share Posted November 3, 2020 Hi , I don’t know how to fix motoplate or fima mag, ignition , , I have noticed ,, burnt spots on my Fima and week spark motoplate , , so I switch most of my buls to conventional points condenser , Because of the cost $$$$$ , like most ebay sights asking 300 to 500 for ignition , , that my 2 cents , cheers Quote Link to comment Share on other sites More sharing options...
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