That looks like more than just being burnt out. Something may have torn it up causing the short and burn damage. My guess is a magnet let go. Dam i hope you get it figured out.

 

My first thought was that the center broke loose when ya killed the motor at your stop.

It just went down hill from there real fast.
Just throwing stuff out there

WP

 

The only thing I remember about the other bike with similar damage, was something about the rotor and stator being the wrong size match for each other, and that was 2nd hand info at the time; I just helped reassemble it. As to how the center of the rotor would get dismembered, I don't have an answer. I would guess that if the rotor magnets were rubbing on the stator or a piece broke off something and jambed up the rotor (which is quite plausible by your pics), then the center could get ripper apart because the crank is still spinning. Rotors always have "no sharp blows" stamped on them; did someone install it with a hammer and weaken the center?

Have you checked your crank runout? Worn crank bearing? If your crank is not spinning true, I would guess that could mess up the clearances between rotor and stator and cause your issue. I guess the real question is did the damage occur because the center of the rotor failed, or did the damage cause the center to get ripped out?

I'd suggest checking crank runout and main bearing, if those look good, reassemble with quality new parts.

 

That looks like physical damage to rotor magnets.
Looks like it got jammed and locked, causing all the damage.
Is it possible that clearance between rotor magnets and stator ends is really really really close or mismatched?
Could it be that you have high electrical demands on unit for heated gear and that causes stator to warm-up and expand, the expansion then causes stator to hit rotor magnets due to being mismatched?

 

"I'd suggest checking crank runout and main bearing, if those look good, reassemble with quality new parts." I would definitly do this. A dial indicator mounted to check concentricity of the shaft to show any wobble. You can pull the plugs and use the sprocket nut to slowly rotate the engine to check for any off-center wobble of the sprocket shaft. It's all all apart so why not. Harley motors have alot torque and mass spinnin. The run-out limits should be in your manual-------------RJ

 

I've had the center bust out of the rotor on my 93in FXLR. Stator didn't get damaged & all of the magnets were fine. It's just one of the things that just happen. I believe Cycle Electric makes a heavy-duty rotor to address this issue.

 

When you go back together with it, make sure the compensator nut is not bottoming out, check sprocket alignment, and tighten the hell out of the compensate nut, that's all I have without seeing it.

 

Your 10 spline crank is probably damaged in the area where the alternator rotor fits. The tooth width should fit snug on the spine in the rotor. When mine stripped out, I took a small ballpeen and carefully rolled the edge displacing metal to get a tight fit. I was careful to stay off the center so as to still keep things centered. If there is any rock fwd and back, when you nail the throttle or engine brake abruptly, no matter how tight the compensator nut is, the rotor will rotate both directions. Just a matter of time, it will wear the face also as if the compensator nut is loose even though it is still securely bonded in loctite if you use red permanent.

When mine stripped and I got another, the parts man told me the replace a couple dozen a year on the old style 10 spline. Why Harley went to a seration. It looks weaker but really is not and it is a lot easier to control the tolerance since both parts are broached. The 10 spline crank must be milled.

 

Seen a lot of hashed charging system parts over the years but that's a first with the center cut out of a stator like that, damn dude what did you do ?

 

That's two different failures. Engine was rebuilt two years ago at Kendall Johnson's shop. Hoping the Cycle Electric kit takes care of it if not we'll have to tear it down again.