Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Shazaams! Posts > Shazaam! on Electrical systems > 916 Electric problem! HELP (ignition system explained)

[CipiVTS]

Hi all,

I have a Ducati 916, 1995.

2 weeks ago i was driving my Ducati and suddenly it started to misfire, wouldn't rev over 3000rpm and finaly engine stopped.

checked at service and noticed that a connector from the 2 wired alternator to the regulator was melted, so it didn't charge and finally the battery was drained.

Fixed the wires and it went ok.

I remembered in the last weeks before the incident the bike's acceleration was poor/harsh (seemed like the spark was not strong enough to ignite all the mixture). Finally realized why.

So after fixing the wires we checked the voltage of the alternator and it was really bellow the standard data:

1500rpm 25V instead of min 35V
3000rpm 50v instead of min 75v
and 6000rpm 85V instead of min 140V

Also the regulated voltage was bellow 13V (recommened is between 13.5V and 15.5V)
With the main light on the voltage went bellow 12V

So the next day i changed the battery with a new one and the readings improved a bit, but still bellow accepted ones.

I also realized the misfire while accelerating was not so strong as before and the engine reved smoother throught the range.

WE measured the stator's resistance and we noticed both yellow wires ahd resistance with the ground (so something must have been wrong with the stator)

Replaced the stator with another used one, and checked the readings again.

Nor ground resistance so the stator must have been ok, but the alternative voltage reading are pretty much the same with the previous one. The only thing that changed was the regulated voltage which is now 13.6V at idle and 14.0 V while revving. The rev increase is realy smooth in all gears and the bike runs very well in all gears.

The only problem is when i turn the main beam on and suddenly the regulated voltage (measured at the battery) drops to 12.3V. If the fan starts it even goes bello 12v. If i rev it a bit it jumps to 13.3v

Driving with the lights you can really feel a differnce vs without. Harshness and misfire appears again while accelerating.

So in this case, can anybody give me any advice what do i have to replace?

Is this normal to have this regulated low voltage? Is because of the regulator unit being faulty? Or is it because of the generator's stator or rotor being damaged ?(and that's why the low alternative voltage readings)

Please help... 1 generator costs ~400 EUR and 1 Regulator is ~220 EUR. Is it worth it that i should buy both?

Thanks

Please hel