Deffo regulator...classic symptoms. Happened to me only recently on my 1098R. Previously happened on my 748 in 1998. That's progress!
cheers guys, starting to be convinced myself after googling it all now. Will get the battery back on and then make that the next step.
On ours the alternator wires weren't too bad, the best thing u can do is get it running with a multimeter on there and see what u are getting across the battery Sent from my iPhone using Tapatalk
Ok, just wired the battery back up and it fired first time. Concerned about riding home 30 miles on the motorway though. If the reg/rec has gone, will the battery just not charge and slowly die, hence why I got a long way before any problems on the way to work?
Ok so I rode home, first 20 miles of the motorway were uneventful then noticed my headlight was getting dimmer and she was starting to miss. They got so dim that I turned them off and the ride smoothed out a touch. The missing got slowly worse but I managed to just get home. Therefore I'm assuming the first 20 miles were OK because the battery was full of juice. It wasn't being recharged so that's why I started having problems. Will have a proper look at it tomorrow for all the things you guys suggested like the plugs from the generator but is it still likely the reg/rec has failed?
Yes, it's up there with the main suspects. The others being:- The wiring alone, between reg and alternator going high-resistance* usually because of corrosion on the contacts of the plug that Steve mentioned, located behind the battery bracket ( can also be the copper wire alone causing this though) - if this is the case, both of these needs addressing urgently/The alternator windings could have failed/The battery could be failing, if wet type, then acid solution could be below the plates for example. *As previously mentioned, it's also worth routinely checking all leads and connections associated with charging circuit as these can contribute to the overall problem, also a combination of several of the above can happen at the same time - A multimeter will be invaluable in helping to sort this out. I don't know how long your journey home was, but the fact that you manage to get home mostly with the headlights on indicates that this is a fairly 'slow fail'.
Classic symptoms, 20 miles with lights on and up to 50 with lights off on a fully charged battery. I think we have covered the most likely items to check. Steve
Ok so finally got around to having a poke around the 748. Stripped off the battery box and found that the two wires from the Reg/Rec had disintegrated. (Picture posted below) Thought great, quick cheap fix and soldered some new wire in. Recharged the battery and put it all back in today. Went for a ride and she ran beautifully during general driving. Whenever I came to a crawl behind traffic or approaching junctions and the revs dropped off she just died! Started ok and got her home after a few times of it doing it. Played around with it and found that at idle if I blipped the throttle to only about 2000rpm she would die when she came back down to idle. Is this problem linked or is it totally seperate? Could the Reg/rec have failed spiking the voltage and melting the wires and still need replacing?
Rec/reg fkd. Get digi multimeter across terminals when running to confirm. Anything less than 13V is no go.
Yeh you were right, voltage didn't change at all when the revs were increased. So will change the reg/rec. Any chance you know if I can use a later one like this: http://pages.ebay.com/link/?nav=item.view&alt=web&id=331786234783&globalID=EBAY-GB As its massively cheaper than an original or older one. The only difference I can see is that mine has the one white plug and then two wires which I presume go off to the alternator. This one has the white plug and then a second plug with three cables. Did later models have different wiring from the alternator? If so can I modify the wiring on the newer one to save me a load of money?
Yes 2 wire is single phase. 3 wire is 3 phase. You can use a 3 yellow and just tape up a yellow i think but I haven't done it so have no experience how well it works. Regulator Rectifier for Ducati 748 916 750 Paso 944 ST2 Monster 750 900 New Set | eBay This is correct and cheap. Don't know if theyre any good. I use shindegen which are reliable but theres newer tech available now which might be better.
Tans, you are buying a replacement regulator rectifier which is probably the least reliable part of your bike and most likely means to cause a breakdown. Get the correct regulator (with two yellow wires not three) and make sure the connections are very tight and very clean otherwise you will be replacing it within a few months. They can melt holes in your battery if they fail over voltage or simply stop producing dc if they fail to low/nil voltage.
And I'm back again......... Ok replaced the reg/rec with the correct one for its age. It wasn't OE and considerably cheaper but it was the right one nevertheless. Changed it and went for a ride, managed 40 mins of it running fine then and put it away. Got up next day and rode it to work, pulled into the petrol station with it running nicely. Went to start it and nothing, battery was dead as anything. Got a local garage to recover it but they are now baffled. They can't find the fault, they are getting a reading of 22v coming off the reg/rec and don't know why? To be fair to them they don't usually deal with Ducati's but a bikes a bike right? They are speaking to a specialist Monday but it's starting to get expensive so any clues guys? Could it be that I just need an OE reg/rec?
Looks like you still have reg/rec problems, as yours is a single phase bike it should be charging the battery at around 13.5 anything over 14.5 to 15 is overcharging on the single phase bikes. It looks like you may have cooked your battery as well if it is now dead unless you have burnt a connector somewhere. Steve
