I need to catch up with everyone. I have some thoughts. Maybe not too important, but I hope every bit helps.
Mary B: Wire size looks close to the same... but that new stator has 3 extra turns per coil if my count is accurate!
mab: The stator does look like 3 extra turns on the top layer, but I wonder if that's just to compensate for fewer turns than original on the lower layers? Hard to tell.
In theory if there are extra turns that should raise the open cct voltage but actually reduce the maximum current I think.
I can't think a few turns difference would affect the regulator that badly - it ought to work over part of the rev range and only lose it at the top end. I don't believe the phase sequence could matter, and if one phase was wired the wrong way (e.g. trident rather than star) it ought to have shown up on the voltage tests.
I see more turns on the outside, too. This which implies there are more turns on the INNER layers, too. There could be a lot more turns on these stator poles than the original. It's enough to convince me that the stator will produce a much higher voltage at any speed.
TechAdmin: The stator honestly looks well done, the guy has been doing it for a very long time... I'm... Clueless.
Quality work, done to the wrong spec, maybe.
Bruce S: ... can't go back and re-read if you replied with the Specs of the regulator. Could you post those PLZ, if the stator is now outputting too high a voltage, it'll throw the regulator all out of whack.
Bruce, it would be best if you re-read the whole thread. Flavio posted it all, twice actually.
TechAdmin On page 611 it shows the values that the stator should have... It says 46V or higher at 4000rpm, I was over 60V at 3000rpm, I did post a video about...
Here: https://www.fieldlines.com/index.php/topic,150320.msg1054920.html#msg1054920
That matches my count of the turns. 50% more turns is 50% more voltage.
TechAdmin Expected resistance 0.1-0.2, I actually have 0.5-0.6 ohms, much higher.
EDIT: yes, seems higher than originally measured in the first post, this multimeter is probably more accurate (costs about twice as the other one, it's twice as big and has more stuff).
Regulator specs are nowhere to be found, not a single manufacturer releases those.
You got me there. Using two meters for very low resistances like that, the resistance in your test leads could be changing the results too much. Let's say those numbers aren't unreasonable (the right order of magnitude) but can't judge more than that.
JW: Use the RMS feature on your meter,
Unfortunately, I don't think your meter can calculate True Root-Mean-Square, which is what "true RMS" means. In layman's terms, "RMS" means an average that doesn't get messed up by negative voltage. And "true RMS" means the meter doesn't get fooled by crooked waveforms or very high/low frequencies. But your meter doesn't do that so it's a moot point.
What is important, and JW was pointing it out too, is that you tested your old stator with your old meter and you tested the new stator with your new meter. So again, the numbers won't necessarily match because maybe the old meter was reading too low for some reason, and you won't know it. I still think it's worth checking against your maintenance manual (which you have). In a way, having a true RMS meter would help but you can (and have) diagnosed this without that.
OK. Thanks for bearing with me as I went through that. I needed my own chance to consider the testing you've done so far and what you've learned.
Now finally something to add. All semiconductors have limits to what they can tolerate. The most important limits are current, temperature, and voltage. Actually, current and temperature are almost the same, because current causes heating, of course. I list them separately because you can cause a semiconductor to fail in a hot environment with low current, and vice-versa. The other thing that kills semiconductors is voltage. There is a limit to the "pressure" they can tolerate before the bonds between the material layers "blow up".
The tolerance of semiconductors to high current is fairly good - they can take an overcurrent for a while. You can get away with passing 15 Amps through a 10 Amp rated diode if you keep it cool and the voltage is low and there aren't any spikes. For a while, though not forever. Tolerance of temperature is less tough, especially if current and heat are combined. Tolerance of too much voltage they don't have at all. Take a diode rated for 100V and give it 150V and the magic smoke gets out real quick. That's what could have happened to your regulator. Its diodes are rated for the highest voltage the stator is "supposed" to generate if it's open-circuit with no battery on a typical Ninja bike. Let's guess that voltage is 100V and the regulator can't regulate that without the battery. If your stator peaks at 150V when the motor is redlined, that would easily explain the dead regulator.
Your choice to talk to the person who rewound the stator seems to be the right thing to do, now. They did good work, so they may be equipped to do a re-wind without too much trouble.
