Any idea why the output voltage of the alternator should go down as the revs go up? I would have thought it would be the other way round.
The alternator wires are soldered directly to the voltage regulator. I have a voltmeter fitted to my bike and have noticed that the voltage across the battery at idle is about 13.8 to 14v but if I rev it to about 5,000 it drops to about 13v.
This doesn't seem to affect the bike at all, the battery is always fully charged and starts fine even in cold weather. I am just curious.
Malcolm
i'll take a stab at it..
how about this:
since the charging system seems like it is up to par, my guess is that the excess output is being shunted to ground by the regulator. as the battery has a full charge, any extra "top" charge is being used up by the coils. i think if you watched a digital voltage meter long enough, you would see the voltage rise and fall a few tenths of a volt when the battery drops a bit and the regulator kicks in.
--Lucky