Stator question

[SoCal250]

(not really a model specific question)

What are the common or possible causes for a charge (source) coil to fail on a stator for a bike with CDI?
I replaced a bad original stator with an aftermarket unit because OEM was not available. After installing the new part the bike died on the first ride after only 15 miles, and has no spark again. Wondering if maybe it was just a part failure in the aftermarket unit, or if there's something else in the bike that may be killing charge coils? 

I'd like to avoid this happening again if possible, when I get another stator to install. Thanks.

[rodneya]

Current draw above the rated output killed a stator on my bike. Im sure the part being well over 20 years old didnt help the situation.

I have seen a lot of threads online regarding aftermarket stators either not working at all or failing very fast on multiple bike models.

Have you checked if there is a vape stator available form your motor?

[SoCal250]

I'm thinking it could just be a coincidental failure, or the intermittent short I found  and corrected in the main switch might be the cause. The switch has 2 wire pairs; the lights and starter are on one pair that was OK, but the ignition runs off another pair that I found to have random loss of contact that was very difficult to see the failure.
Replacement stator was a $180 unit from RM Stators in Canada, not a cheap Chinesiem part. RM is supposed to make good quality replacements. Their service and shipping were top notch, so I can for sure say that about them.
The bike is a '05 Yamaha XT225, so no Vape available.

[m in sc]

the winding protections do break down over time as well. (the coatings)

[RDnuTZ]

I'm thinking it could just be a coincidental failure, or the intermittent short I found  and corrected in the main switch might be the cause. The switch has 2 wire pairs; the lights and starter are on one pair that was OK, but the ignition runs off another pair that I found to have random loss of contact that was very difficult to see the failure.
Replacement stator was a $180 unit from RM Stators in Canada, not a cheap Chinesiem part. RM is supposed to make good quality replacements. Their service and shipping were top notch, so I can for sure say that about them.
The bike is a '05 Yamaha XT225, so no Vape available.

Check your ignition coil. Could be what you suggested- but you DID have it running, so suspect weak link in the chain theory here. 19 year old OEM Yamaha ign coil would be a likely suspect.

[m in sc]

true. could be really anything in the system.  did oyu do a kickover w it disconnected and look for ac voltage output?

[SoCal250]

Found the issue, and the reason why I wasn't getting any meter readings from the yellow wire from the source coil.





And it almost looks like the coil has been making contact with the rotor. Don't remember if it looked like that when installed. The old OEM one doesn't look like that.

[Daytona1]

Loose rotor, bad crank bearing?

[SoCal250]

Loose rotor, bad crank bearing?

That possibility came to mind, but I don't feel any play or movement in the rotor. It's solid. And the original stator does not have those marks so I don't think it's the cause. I measured the distance from the mounting ring to the outer surface of the source coil on both parts and the replacement unit was slightly larger, so it may just be a manufacturing issue. Or it may not have been touching the rotor at all and could have been dropped or bumped against something before I installed it. I don't recall what it looked like when I received it and put it in.

Sending the stator part back to RM Stators today on a RMA. They will look at it and possibly cover it under warranty.

[SoCal250]

Just as I was getting ready to head out to the post office this morning with the return, I got an email from RM Stator support saying there was no need to return my old one because they had reviewed my test results and photos and determined that the part was defective. A new one will ship out Monday.
Despite the part breaking and the headaches it caused, I'm really happy with their support and communication.

[m in sc]

wow thats awesome. ive used them a -few- times and always been happy

[2 Smoker]

Great service is very difficult to find these days. 

[SoCal250]

The stator issue is resolved! Extremely happy with the service, communication, and support I got from RM Stator. They're a great company and I highly recommend them! Their stators come with a 2-year warranty.
Support timeline:
   -Reported the issue to them on a Thursday, and Friday they provided an RMA # and I supplied additional details, test results, and photos as requested.
   -Saturday morning they confirmed the unit was defective and that they would be shipping a warranty replacement unit on the next business day.
   -Monday the part shipped from Coaticook, QC, Canada by FedEx.
   -Wednesday at noon the new part arrived at my house.
They provided daily status updates each morning by email, including Sat & Sun mornings. Pretty unheard of in business today.

I'll post a follow up in the 4-stroke section for this particular bike.

EDIT: see: https://www.2strokeworld.net/forum/index.php?topic=6394.0

[SoCal250]

A follow up about the stator and some of the questions about the first RMS unit when I inspected it. When the new one arrived it had the same flat spot on the outside of the coil, so that seems to be normal with these aftermarket units, and not an issue.

[1976RD400C]

Looks like after they assemble it, they spin it in a lathe and make it concentric and set the OD to spec.