audibobby Posted April 3, 2014 Share Posted April 3, 2014 Hi guys looking for some advice or ideas to move forward with my project. I have a 1977 DT125 with electric start using the starter/generator setup (model type 1G0) and having tested the armature, rotor, brushes and battery, cannot get the bike to turn over on the button or charge the battery whilst the engine is running via the kickstart. Getting hold of replacement parts is proving difficult and so I was wondering if anything else could be fitted to charge the battery from the running engine. I am not really bothered about the electric start side of things but as the bike needs a battery to run, I do need to find either a replacement or alternative. Any help or advice is much appreciated and please be aware that I intend to keep this bike and am not looking to get the info I want and then take no further part in the forums as I understand many do. I will give any help I can and hope i can be of use to other members in the future. Link to comment Share on other sites More sharing options...
dt502001 Posted April 3, 2014 Share Posted April 3, 2014 Sorry I cant help with any parts But why not give REX speed shop a try thats something up his ally Link to comment Share on other sites More sharing options...
audibobby Posted April 3, 2014 Author Share Posted April 3, 2014 Thanks for that mate. Gave them a call and they gave me some good advice and another contact number but apparently I can ditch the electric starter and fit a regular DT125 generator which would be ideal. Thanks again and if anyone else has any ideas or points to make then I'm all ears. Link to comment Share on other sites More sharing options...
dt502001 Posted April 3, 2014 Share Posted April 3, 2014 I would have thought that you could swap it out as well but I personly dont have any experience with a dt125 cira 77. Start a thread in workshop of the conversion with lots of pictuers so if someone else needs to do it then they can follow. Link to comment Share on other sites More sharing options...
audibobby Posted April 4, 2014 Author Share Posted April 4, 2014 Will do that when I get round to it. It would probably be quite helpful as apparently it is a common problem on bikes with the starter/generator. Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted April 4, 2014 Moderator Share Posted April 4, 2014 Not sure if it helps but many of the older bikes need strong batteries to start them. My YA has a armature starter generator and the battery needs to be very good to start it. Link to comment Share on other sites More sharing options...
audibobby Posted April 4, 2014 Author Share Posted April 4, 2014 She starts on the kickstart and has a brand new fully charged battery but there is no charge to the battery whilst she is running so eventually the battery would drain and she would die. The guy I spoke to at Rex speed shop told me that the best thing to do would be to get rid of the starter/generator setup and source a generator from a DT125 of the same age that was made without the electric start. He also said that in his opinion the engine would probably last longer without the very heavy armature on the end of the crank. To be honest, working up a sweat kicking over the bike for ten minutes and then realising the engine cut out switch is in the off position is half the fun I do appreciate what you're saying about the battery needing to be good to turn the engine on the starter though. Link to comment Share on other sites More sharing options...
audibobby Posted April 5, 2014 Author Share Posted April 5, 2014 One thing I have noticed is that the magnets in the stator assembly do not attract. They Will not even hold a paper clip. Does anyone know if this is normal and do the magnets only pull when they are energised? I will test this by energising the coils when the stator is removed and see if the magnets pull. If not then I think that is where my problem lays. I will report my findings but any other ideas are welcome. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted April 5, 2014 Moderator Share Posted April 5, 2014 The system sucks, you need about 4000rpm for it to make up for its own power needs. Junk it for the kicker unless you really want it. As to the load on the crank, you will still have a flywheel??????? Don't forget you will have to swap out for 6volts as well. You only get 12 on the leccy starters. Just remember you ideally need a points set up, with the flywheel. If you get anything intended for cdi you will need the appropriate cdi unit too. Yam used 2 different systems. Also 125, 175. No difference as far as ig goes. Link to comment Share on other sites More sharing options...
audibobby Posted April 5, 2014 Author Share Posted April 5, 2014 Thanks for the advice Cynic. I will get shut of the leccy start wiring come what may but just need the unit to generate enough energy to charge the battery. The output voltage at the minute is 0.1 volts and should be 14!!! Something is clearly not working at all as opposed to not working to full potential. Link to comment Share on other sites More sharing options...
audibobby Posted April 6, 2014 Author Share Posted April 6, 2014 Just a quick update for anyone who may be interested. I checked the stator magnets and they do pull when energised so they are electro magnets as opposed to permanent magnets and are working ok. Having read up on the generator side of things, I did not realise that the regulator energises the magnets to whatever level they need to be to supply the voltage required to service the load. I checked the pull of the magnets by energising the starter coil and so I am thinking that they are not being energised at all by the regulator. Could this be the problem, a duff regulator?? I have one coming this week so stay tuned for hopefully the conclusion of this saga Link to comment Share on other sites More sharing options...
dt502001 Posted April 7, 2014 Share Posted April 7, 2014 Surely you could back probe the leeds from the regulator with the bike running to check if any output is present before buying a new regulator,or feed the circut to check the un regulated out put? Link to comment Share on other sites More sharing options...
audibobby Posted April 16, 2014 Author Share Posted April 16, 2014 Hi again guys, been so busy with work that the bike has taken a back seat but will post updates when I get going on her again. Link to comment Share on other sites More sharing options...
audibobby Posted May 11, 2014 Author Share Posted May 11, 2014 OK here we go with the update........... ran through everything again with the multimeter and found my problem. Can't believe I missed the glaring fault that would have saved me hours and a few quid to boot. The starter coil had a short to earth through the starter generator housing and as both coils are used simultaneously when running then it follows that the charging coil was also earthed and therefore no start and no charge once running. I can only think it was my enthusiasm to get her running and get on her that caused this schoolboy error but as they say "you live and learn". I started to strip out the magnets from the stator assembly with a view to re coating them in insulating lacquer and was mid way through this operation when a used starter generator unit popped up on fleabay. Got it delivered for £45 and all is now running and charging as it should She even starts using the leccy start but not using that as I don't want to break it again. If anyone else has the same problems with the DT125E then here is what you should be looking for from the starter generator assembly using a multimeter. Separate all the leads from the main terminal block on the face of the starter generator unit and then measure resistance between both the thicker tabs protruding from rear of the actual unit through the cut outs just above the terminal block. Make sure nothing else is touching these tabs other than your test probes and the resistance should be 0 ohms or very very close. This is the starter coil. There should be no continuity to earth from either of these tabs (easy for me to say that now ) Next take a reading between the other two thinner tabs coming through from the rear of the unit. The resistance should be around 4.8 ohms plus or minus 10%. This is the charging coil and again should have no continuity to earth. If all these readings are ok and you have triple triple checked them then the stator is ok and not at fault. Hope my slack effort helps someone by being a lesson in the dangers of overlooking the basics and jumping to the more complicated stuff to find the fault. Link to comment Share on other sites More sharing options...
audibobby Posted May 11, 2014 Author Share Posted May 11, 2014 Just to add, I think I found the point where the old unit was earthing and will re lacquer and re assemble when I get time. Hopefully this will give me a spare for future use as these are like hens teeth to source. Thanks for all your input on this topic, it was all very much appreciated and it's great to know that help is there when needed.........thanks again guys. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted May 12, 2014 Moderator Share Posted May 12, 2014 Good news, can you add some pictures to clarify the infomation. These starter/generators come up pretty regular. This is the kind of info they need. Never know, if its good it might get pinned. Link to comment Share on other sites More sharing options...
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