Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > 916 alternator/regulator

[tonto67]

Ok well I just fitted a brand new Generator and RR to my 916. The old Gen turned out to have burnt wires inside the case. So burnt in fact that the insulation had fallen apart exposing bare contuctor. When I installed the new unit I tested the unregulated voltage and I was only getting 95VAC @ 6000 rpm. I'm gonna try a different meter when I can get hold of one.
One odd thing I noticed when I was doing final checks. I measured the redulated voltage across the battery and at idle I got 14.2 volts but as I revved the engine the voltage dropped to 13.4 at 6k rpm. Now I have read that a dirty fuel filter will cause the pump to draw more current. Since the pump is working harder when I rev the engine I'm hoping its just a dirty filter. I have a new one but ran out of daylight today. Question: Is it usual for the voltage to drop when the engine is revved or should it rise/stay the same?

[skidlids]

as the pump is running at idle I would have thought a dirty filter would have put a load on the battery even at idle and pull the volts down not let them sit up at 14.2V.
I have no experience of the RR51 so not sure of its regulating characteristics so have no idea how it behaves

[tonto67]

To be honest I'm just clutching at straws now. I have replaced the filter with a new one from Ducati. Gonna butcher the old one and see how bad it is. I measured the battery voltage this morning, it read 12.55 volts, acceptable as far as I know for a battery 12 hours rested. I started the bike and allowed to idle @ 1200rpm. The meter read 14 volts. Now here is the problem as the revs rise the voltage across the battery drops to just over 12 V @ 6K. This is not right. I also have an R1. To get a comparason I checked it and got 14v at idle rising to almost 15 @ 5k rpm. To me this is how the ducati should act with a new RR, generator and battery. The only other component is the flywheel. Im not well briefed on magnetism but is it possible that a potentially 13 year old flywheel could have lost some magnetic power. As mentioned it a previous post I did check the unregulated voltage after installing the new generator and only got 95VAC where I should be reading at least 140VAC. Since there are only 2 components (generator and flywheel) interacting to produce the unregulated voltage, is it reasonable to suspect the flywheel is duff? Anyone with any insight please let me know. Im 400 quid out of pocket so far and still none the better for it.