Rotor melted itself 500km after rewind?

[JNaw]

Hey all, hope y'all have gotten out with the nicer weather coming through in Canada here.

Anyhow, took the bike out yesterday for the first ride of the season, and now my rotor self destructed (again).

Originally it died last year, and brought it to a rotor/motor rewind shop (seems to deal with mostly vacuum cleaners but does it all). $300 later and rotor was back in action.

Put about 500km on it and then parked it for the winter.

Battery was weak trying to start it (my dumbass forgot to plug it in at my storage place over the winter) but a quick jump start and she was running great. THEN BAM, 50km later the headlight stops working (been here before)

So immediately today, rip the brushes out. Sure enough, there's a melted copper wire strand sitting there and no continuity across the rotors again. (EDIT: second look seems to be a different gauge of wire, as well as a piece of white insulation about the same length sitting in the same area, wires going to brushes are fine, so not sure where this came from just yet...)

Battery is at 11.44v (after riding with a dead alternator for atleast an hour most likely)

What's going on? When I originally got it fixed, she was charging around 13-14v.

Could the battery be bad? (Can't see that as it holds a charge just fine..) Did the rewind shop use the wrong insulation rating for the windings?

I'm at a loss here..last I checked, voltage regulator was operating fine, and stator was producing correct AC voltage on all phases. Any input would be great. Thanks.

Edit 2: A PMA kit is 285usd from Mike's XS, considering a rewind will cost about as much, may just upgrade the whole system and be done with it.
Photo attached of the carnage

 

[650Skull]

That looks catastrophic. No way the wiring should be seen at all from there. The winding must have been loose a hell with minimal resin. The output seems a little low for a fresh rewind. Depending on the wire core size the output can vary, there is/was a re-winder in the states who used heavier wire on their rewinds and i think that was putting out around 4.2 or 4.5 working as good.............If you cant get your money back then look up @Jim on here. Doe a great rewind.

Jim's rewind services thread............think even with the exchange rate and postage if it came to $300Can you will be better off. Pretty sure it wont. I got one sent to NZ and i think that was around the $NZ230.00 mark
https://www.xs650.com/threads/rewound-alternator-rotor.54276/

 

[JNaw]

That looks catastrophic. No way the wiring should be seen at all from there. The winding must have been loose a hell with minimal resin. The output seems a little low for a fresh rewind. Depending on the wire core size the output can vary, there is/was a re-winder in the states who used heavier wire on their rewinds and i think that was putting out around 4.5 or 4.7 working as good.............If you cant get your money back then look up @Jim on here. Doe a great rewind.

Jim's rewind services thread............think even with the exchange rate and postage if it came to $300Can you will be better off
https://www.xs650.com/threads/rewound-alternator-rotor.54276/

Thanks for the quick reply. Yeah originally was "sealed" up with yellow tape after the rewind but that's long gone.

Doubt he will refund as it's been almost a year since the rewind.

How about the PMA swap? Sort of done with tinkering with the stock charging system.

Also, quick look through Jim's thread, I definitely used a gear puller to originally get the rotor off. That may have been my cause to this problem (didn't know better don't flame me aha. The rewinder didn't check runout ofcourse)

 

[650Skull]

Rare for a stater to fail. The Factory S/S Reg/ Rect are also pretty good although there have been a few cases where the Reg side has failed, Getting on a bit but till not real common. A good thread on replacing Factory Regulator and Rectifier on points models and the S/S Reg/Rect on TCI models, with a Bridge Rectifier and Automotive Regulator, Reasonably cheap and reliable. It is the go to upgrade if the charging components fail and if i remember correctly there has only been one case where they failed due to the Bridge rectifier.

https://www.xs650.com/threads/diy-reg-rec-5twins-and-jim.55842/

 

[mrtwowheel]

I always said that any electric motor guy could rewind a rotor, but they won't get the epoxy right to hold it together. I wouldn't give up on a good design because of a loose wound rotor built to fail.

 

[jetmechmarty]

Edit 2: A PMA kit is 285usd from Mike's XS, considering a rewind will cost about as much, may just upgrade the whole system and be done with it.

From what I have read on here, that would mean a fresh set of problems.

 

[wildav]

When the alternator on my 79 failed, I went with a pma. I do not recommend the xs charge that Mike's xs sells unless they have a different source. Mine lasted all of 300 miles. When I did the fix, I went with a used Kawasaki stator from ebay and used the magnet rotor that came with the xscharge kit. Had to do a little grinding on the mounting base to make it fit as I recall. Somewhere on the forum is a list of alternate pma's from different makes of motorcycles that will work. Alternate mosfet regulators are also listed. I was sol on a refund because I shelved the MikesXS parts for a spell before installing and the warranty had expired.
P.S. Not knocking the original Yamaha system, But in my case it was a much less expensive route to take. If I had installed it in a timely manner, that is !

 

[gggGary]

@Jim ????

 

[Jim]

All covered Gary... thanks!!

 

[JNaw]

Thanks everyone. Jims got a rotor I'll be grabbing from him soon.

As for the stator, hopefully that's in good shape, have yet to take a look and see where that mysterious strand came from.

 

[mrtwowheel]

Two brands that have worked flawlessly for me on similar Honda's is Caltric for the stator, Rick's for the rotor and a DIY copy of Oregon's Reg/Rec. All great prices and reliable. Will possibly order from Jim if a rotor is needed for other bikes in the future.

Edit..........All three parts for +/- $200

 

[Jim]

Thanks everyone. Jims got a rotor I'll be grabbing from him soon.

As for the stator, hopefully that's in good shape, have yet to take a look and see where that mysterious strand came from.

Stators are as close to bulletproof as you can get on an XS. Hopefully it's still good.

 

[Jan_P]

Since this has happened twice

and now my rotor self destructed (again).

Measure the axle tap run out can be something to consider
and look inside the stater if it has been hitting there.

 

[JNaw]

Since this has happened twice

and now my rotor self destructed (again).

Measure the axle tap run out can be something to consider
and look inside the stater if it has been hitting there.

Good point.

You talking about the axle the rotor rides on?

The first time I'm not too certain what caused the problem, but looked original so just chaulked it up to old age.

 

[Jan_P]

Good point.

You talking about the axle the rotor rides on?

The first time I'm not too certain what caused the problem, but looked original so just chaulked it up to old age.

Yes Sir my first XS 650 had taken a hit in a crash And twisted the crank a little causing vibrations
and the rotor had hit the inside of the stater slightly.
Which I did not know then just believed it was the bikes normal behavior
On a rebuild the shop adjusted it and the outer bearings was replaced
Vibrations disappeared

I rewound the rotor don't remember fixing the stater then
I remember seeing the numbers on allowed run out in some service manual
Maybe can find it there

https://thexscafedotcom.wordpress.com/2011/01/10/xs650-manuals/

 

[JNaw]

Hey all, if anyone's curious on an update:

Got Jim's rotor installed. (Thanks again man)

Old rotor seemed to have shorted out on the housing due to vibrations. See pics attached. I'd try to repair it, but any soldering job I could do I doubt would last with vibrations.

Anyhow, just gotta fill the battery, and a few other minor things and she's back on the road.