The battery voltage on my D600 is always a bit low. It just about fires up, but I sometimes have to push start it. I suspect that the stator is faulty (even though the bike only has 16.000km on it.) I have inspected the following:
Stator output at 5000 rpm is ~13VDC, which is way below the 14-15VDC specified by Yamaha. Changing the rectifier with a spare one did not help.
I have done a parasitic draw test. Connecting the multimeter inline, as well as between each fuse terminal, I measured zero amperage whatsoever.
I have measured the voltage that comes directly out of the stator. Each phase is consistent in showing around ~58VAC at 5000 rpm. It seems low, but Yamaha supplies no correct figure.
On all three wires, resistance comes down to about 0.5ish ohms. This is a smidge higher than the 0.24-0.36 ohms that the manual dictates. Of course it's hard to tell on a cheap meter.
Is there anything that I missed? Or should I just go ahead and buy a new stator?
