Rotor Overheating

[Halloweenie]

I have an odd issue, my HHB PMA rotor looks like it overheated and appears to be degaussed. Its surface shows heat damage and, while still installed on the bike, has almost no magnetic pull on the outside face. I have yet to pull the thing off, but the surface of the rotor is brown and the HHB sticker has burned off. I should have grabbed a picture, but I didn't think of it. I will do so in after a day of rest, when I can get back into it.

I only found the problem because the bike died while in traffic this past Tuesday and forced me to get a tow. What is worse, is that it fried my 12 cell Ballistic battery because it discharged below the damage point, so it will never recharge again. I've replaced it with a standard lead-acid battery to test the charging system, and the multimeter shows no charging whatsoever. After pulling off the side cover, I inspected the wiring and I detected no damage to it or the reg/rec, no burn throughs, exposed wires, breaks, and the stator is very secure and it will get a throughout inspection once I pull the rotor. I will say that I am on my second stator, I hadn't put enough torque on the screws holding it to the plate, which allowed it to vibrate to death. I don't know if that may have contributed to my current situation, but I'll put it out there. It is the rotor that seems damaged and as I stated above, it exerts almost no magnetic pull on the outside, even on my smallest wrench. So here are my two big questions. First, am I correct in assuming that a wrench should feel significant magnetic force (enough to pull a wrench to it or hold a wrench in place) from the outside of the rotor, even when installed on the bike? Secondly, what might I have screwed up when I installed my PMA to cause it to overheat? Hopefully I can avoid the same fate for the replacement rotor.

Thank you all for your time and assistance, and I apologize for my absence over the past many months. My health has deteriorated to the point where I am house bound, I only leave to see my doctors or to go shopping, but I always take the bike if I can. I spend very little time on the computer now because I have lost much of my fine motor skills, so typing is slow and painful. However, I am fortunate in that I can still walk with the use of a cane or walker, and for the time being, I can still ride (I even found a way to carry a cane on my back when I ride). I don't know how much longer I will be able to ride, but I plan on enjoying it while I can. Thanks all!

 

[OakBehringer]

Just discovered the same thing in my bike. Still working though. Visual inspection sounds identical. Any else? Any ideas? I hear no rubbing. Not sure where to begin on this. See attached photo.

 

[TwoManyXS1Bs]

Just thinkin' out loud here, in generalistic terms.

The PMA regulators work by dumping excess stator current to ground, causing the stator to absorb the excess energy. Suppose, for example, that you have a 200 watt PMA, but your daytime demand is only 60 watts. That's 140 watts going into the stator. Even more so with a higher output PMA. That translates into heat. Probably run cooler running full lighting...

 

[OakBehringer]

I hear you. That makes logical sense. I'm running a 55w headlight on at all times. Sparx cap. HHB never mentions anything about that being a potential problem. In fact, I have seen him all but endorse that as an acceptable set up.

Stator has low resistance (.6 ohm) across all three wires. No continuity from any to ground. Except... The stator is clearly about to become fried (see attached pic). A couple windings look toast. They are loose.

All my wiring is top knotch, less than a year old, copper bullet connectors with good crimps. Inspection shows no obvious problems.

What's next? I don't really want to put in a new stator and cross my fingers. What could cause this???

Thanks,
Adam

 

[CDNTX650]

Or buy a good series regulator, like the compufire i put on my versys. Shunt regs have alot of heat to deal with. Pretty common to see new bikes toast stators and regulators too. Temps taken at the stator cover are lower using the compufire. I went the preventstive route...most versys owners see toasted stators around 40k miles. Hopfully this series reg. Solves that.

 

[OakBehringer]

I guess... but like, 150 miles is pretty quick to burn out a stator.

You're talking about this? I'm intrigued, but dang, that's another hundred bones!

 

[CDNTX650]

Perhaps just bad from factory. Next round i would definetly spend the money on a good regulator.

 

[CDNTX650]

Compufire 55402. Expensive yes. Pay to play. The compufire probably wont shit out on you like a cheapo shunt. But neither has my stock rotor and stator on my 74.

 

[fredintoon]

My health has deteriorated to the point where I am house bound, I only leave to see my doctors or to go shopping, but I always take the bike if I can. I spend very little time on the computer now because I have lost much of my fine motor skills, so typing is slow and painful. However, I am fortunate in that I can still walk with the use of a cane or walker, and for the time being, I can still ride (I even found a way to carry a cane on my back when I ride). I don't know how much longer I will be able to ride, but I plan on enjoying it while I can. Thanks all!

Hi Halloweenie,
sorry to hear about the shape you are in and I do hope that it's something you can get better from.
About typing skills, I'll see your slow and painful and my typing finger and spacebar thumb will raise you fumbling and inept.
About the stick, clip it to the front fork like Lawrence of Arabia, you don't need it strapped to your back if you fall off, eh?
About continuing to ride, go with a sidecar. Besides us elderly there's paraplegics that use sidecars to keep on riding AND you can put all your stuff in it too.

 

[retiredgentleman]

I hear you. That makes logical sense. I'm running a 55w headlight on at all times. Sparx cap. HHB never mentions anything about that being a potential problem. In fact, I have seen him all but endorse that as an acceptable set up.

Stator has low resistance (.6 ohm) across all three wires. No continuity from any to ground. Except... The stator is clearly about to become fried (see attached pic). A couple windings look toast. They are loose.

All my wiring is top knotch, less than a year old, copper bullet connectors with good crimps. Inspection shows no obvious problems.

What's next? I don't really want to put in a new stator and cross my fingers. What could cause this???

Thanks,
Adam

You should test read the voltage across the capacitor to see how high it gets at 4000 rpm. If the regulator is working correctly it should be able to keep the voltage under 14.5 volts (14.1 to 14.2 volts is best). If voltage is going too high, try turning on the high beam for more load. Installing an on board voltmeter would be a good idea.

Also, something to consider. If these PMAs are manufactured in Taiwan, they are not made to the same high quality that OEM alternators (Hitachi) were made in Japan.

 

[OakBehringer]

You should test read the voltage across the capacitor to see how high it gets at 4000 rpm. If the regulator is working correctly it should be able to keep the voltage under 14.5 volts (14.1 to 14.2 volts is best). If voltage is going too high, try turning on the high beam for more load. Installing an on board voltmeter would be a good idea.

Also, something to consider. If these PMAs are manufactured in Taiwan, they are not made to the same high quality that OEM alternators (Hitachi) were made in Japan.

I checked that a couple times after installing, and the readings were solid. But who knows what happened since then. Right now I have my exhaust off the bike b/c I'm in the middle of a swap (waiting for mufflers to arrive), so I can't get readings until middle of the week at the earliest. I noticed the burnt rotor while I had the side cover open to adjust the valves. Bummer.

I hate the idea of this NOT being my fault (I can't imagine it was), or figuring out what did it. I won't be able to trust the replacement parts.

 

[retiredgentleman]

I checked that a couple times after installing, and the readings were solid. But who knows what happened since then. Right now I have my exhaust off the bike b/c I'm in the middle of a swap (waiting for mufflers to arrive), so I can't get readings until middle of the week at the earliest. I noticed the burnt rotor while I had the side cover open to adjust the valves. Bummer.

I hate the idea of this NOT being my fault (I can't imagine it was), or figuring out what did it. I won't be able to trust the replacement parts.

Has the PMA/regulator actually failed, or are you just saying it appears to be ready to fail?

You said it was less than 1 year old, and only 150 miles. Most electrical equipment have a 1 year warranty. Send it back to the seller and demand a new replacement.

 

[gggGary]

Gotta pile on about a PMA curing your old "unreliable" charging system! Hint; don't count on Chinese parts to solve a reliability problem.
AFAICT most failed stock charging systems are the result of some dummy trying to limp along on a toast battery. First thing I do on any bike I buy is test and (very often) replace the battery. It's frequently too late for some poor overworked charging system component.

 

[retiredgentleman]

Gotta pile on about a PMA curing your old "unreliable" charging system! Hint; don't count on Chinese parts to solve a reliability problem.
AFAICT most failed stock charging systems are the result of some dummy trying to limp along on a toast battery. First thing I do on any bike I buy is test and (very often) replace the battery. It's frequently too late for some poor overworked charging system component.

Well said Gary! Yeah, for years on this site, when talk turns to the electrical system, all you hear is, ............. "That stock alternator is a piece of crap, I'm buying a PMA".

Just one man's experience, over 8 years, but my OEM stock alternator works perfect for me.

 

[CDNTX650]

Same, all three of my engines have good rotors and stators. Although, cdn bikes dont see the heat and our season is half as long.

 

[weekendrider]

Well said Gary! Yeah, for years on this site, when talk turns to the electrical system, all you hear is, ............. "That stock alternator is a piece of crap, I'm buying a PMA".

Just one man's experience, over 8 years, but my OEM stock alternator works perfect for me.

But why wouldn't someone think that?
From the mountain top is heard.
"Change those fuses before you get left on the side of the road"
"That points system/TCI system will doom you to dire situations"
"Upgrade that reg/rec or you will be left to solitary death in some foreboding place"

For 8 years now I get along on the stock parts on the bike in my avatar.
The glass tube fuses, TCI, reg/rec all OEM. But not the battery or brushes.
Sometimes I think maybe the ONLY reason I don't change things is so I can point this out in ornery moments.
Not that I'm a high miler but just commuting is over 300 miles in a . . . . . week.
Side rides go a tad more than that.
I can't blame the thinking of someone when they install a PMA. After all, the other components are shitzen. . . .I know, I've read it on the internet. A new improved PMA (along with other corrections) should open the pearly gates to rider heaven.

 

[OakBehringer]

Gotta pile on about a PMA curing your old "unreliable" charging system! Hint; don't count on Chinese parts to solve a reliability problem.
AFAICT most failed stock charging systems are the result of some dummy trying to limp along on a toast battery. First thing I do on any bike I buy is test and (very often) replace the battery. It's frequently too late for some poor overworked charging system component.

Thanks, and that certainly is the cool thing to say, but it doesn't help me at all. It's a waste of space on this thread and only going to cause other people to chime in about how all of us rolling with a PMA are such dummies. I'd prefer to keep this thread on topic (PMA with burned stator), and it's already starting to derail.

Thanks.

 

[OakBehringer]

Gotta pile on about a PMA curing your old "unreliable" charging system! Hint; don't count on Chinese parts to solve a reliability problem.
AFAICT most failed stock charging systems are the result of some dummy trying to limp along on a toast battery. First thing I do on any bike I buy is test and (very often) replace the battery. It's frequently too late for some poor overworked charging system component.

Has the PMA/regulator actually failed, or are you just saying it appears to be ready to fail?

You said it was less than 1 year old, and only 150 miles. Most electrical equipment have a 1 year warranty. Send it back to the seller and demand a new replacement.

It hasn't failed. The stator apears ready to fail. The windings are burned and I can feel them moving around when I touch them with my finger. All of this was installed a month or so ago, so I assume it to be under warranty from Hugh's Handbuilt. Awaiting a reply from the man himself. The thing I'm worried about is putting a replacement on that also fails, potentially when I'm in the middle of the Mohave desert. If there's something I can do to prevent that...

after reading it sounds like I'm using about 60 of the available 200 watts. My shunt (shit?) regulator is supposed to convert the other 140 watts to heat. If it doesn't do that, two things may happen.

1) too much voltage will go forward to my components, and fry them. For me this really only is my PAMCO (which is still fine). I'm not too worried about blowing a light bulb, they can handle a wide range of voltage.

2) too much voltage will go back into the stator, causing it to get so hot the sticker and paint literally burns off my rotor, and then the stator burns out.

So, it sounds to me like I either got a bad stator that was destined to die or my regulator was not doing its job, shits were about to hit the fan, and maybe I caught it in the nick of time.

From what I can tell, this cannot be the result of a bad cap. Right? It's job is to smooth out the electrical pulses, my problem is from over voltage.

Thanks!
Adam

ps Please please please don't waste the time of people who came to this thread because the have a similar issue and want to find the solution by talking shit about how I'm a dumb fuck for buying a PMA. Thanks.

 

[CDNTX650]

If you do get a new rotor, i would definetly invest in a quality series regulator to go with it. Caps generally work or they fail internally. Should be fine there.

 

[TwoManyXS1Bs]

... I can feel them moving around when I touch them with my finger...

... got a bad stator that was destined to die ...

Could be on to something there. The excess energy dumped back into the stator coils produces heat, and if the heatsink path of the coils is poor, they're essentially thermally isolated, and could get wildly hot. The fact that yours are now loose is not good. I wonder about how the coils are wound upon the stator, how tight and what insulation is used.

It's been a long time, but this kinda reminds me of the buzz/noise and overheat issues of defective power transformers, loose pole/yoke windings and poorly laminated cores. Maybe RG has had some experiences with this and could chime-in...