charging data

[Guest Scorch]

Hi Guys...

Before I start ordering parts:

Coming out of London today, fan whirring, the bike started ticking over at 600rpm. Next set of lights it was fine, lights after that the same thing. Once I got out on the open road it was fine.

My first thought was either tps or charging system. I put a multimeter on the battery when I got home, having allowed the bike to cool a bit so the fan wasn't on.

Engine off 12.5v, Engine on ticking over: 12.7 volts. Engine at 5000rpm: 13.7v

This seems pretty low to me, so I checked the AC voltage from the stator.

20v at idle, rising to 50v at 5000rpm. Virtually identical readings from all three phases.

This also seems low to me, I'd be expecting 70 or 80 volts at 5k.

I also checked the stator for shorts, there are non.

Its a mosfet reg, which is pretty bullet proof, and I've done 10000 miles on the stator, who knows how many it did before I bought it.

The charging system was a bit feeble when I checked it last year, was only getting 13.xx volts then too, but the bike was running fine so I thought I'd leave it until I was sure I had a problem. I'm wondering if the stator has been feeble all along, but producing enough to run the bike, until this hot weather when the fan is on fairly frequently in traffic which has pushed it over the edge.

Thoughts?

[Guest Scorch]

Just found the post I made last year in reply to Blueboy's charging woes, and the figures I quoted then are almost identical to the ones I made today! Is it just taking a long time to pack up?!

[HornetJay 31]

When you have problems like that its 99% the battery, if its under 13 V off then chances are the battery is done for, if the battery is charging then running down dead over a short time its usually then a charging problem bike side, I don't know if this is right, but when I have had a reg/rect go its first signs are the lights going bright then dim.