Unusual stator failure?

[bluewool]

Hello, I am in the process of resurrecting my GS. The latest challenge has been the electrical system. The battery was not charging, I bypassed the rr check and went immediately to the stator output (no need to blame the toaster if the circuit breaker is off) 0vac at all rpm. Ω test revealed a dead short and two opens. I immediately started to make plans to rewind it myself seems pretty dead simple. However, after removing it I may not have to. I have seen the pictures and thought I'd up load the one of my particular failure because I haven't seen any other ones like it. The stator itself appears to be fine, (I'll bring my megger home tomorrow and check the insulation) but the connection of the harness to the stator coil shorted phase to phase. It is not uncommon for poorly soldered joints to fail over time. Hopefully the coils survived and I'll just replace the harness (it has hardened over time and the insulation seems like it could crack away) solder the connection, epoxy them and put it back in. While I'm at it I will DeOxit the connections for the rr and check it over. What really surprised me was the chintzy crimps they soldered over make the connection.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. bluewool,

I've had bad stators pass all of the passive tests but still fail to charge properly. Some of those windings look pretty toasty. Don't be surprised if the stator still fails after you repair the splice. I wish you good luck with that. Right now I'm a fan of Rick's stators. Both the RM Stator and the Electrosport stator have lasted only long enough for the warranty to expire.

Feel free to put your year/model in your signature file so we'll know what motorcycle we're talking about. But I digress...

Anyway, I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[bluewool]

Thanks for the welcome BassCliff,

I have been a member on and off since 1999, mostly off.
Things have kept me from riding for a while.

I am an industrial electrician by trade. That's why I own a meg ohm meter which is an active tester.
So the stator: The windings actually LOOK great, for what that's worth, which is just about nothing, they show no signs of uneven heating on the windings that's a plus for sure. The fibre glass sleeve on the wires kept the heat of the short away from the windings. The crud in the photo is residue from combustion of the wire joint, it wipes off with a Qtip. But without my megger it is all meaningless, I will not be reinstall it without it passing a 1000v test.
If I do need a replacement I will likely rewind it myself( because I have a access to the materials and the knowledge base) or have it done locally because I deal with motor rewinding shops on a regular basis. Anything I learn I will certainly pass on.

 

[bluewool]

well, it was a spectacular fail on the megohm meter test. I could actually hear the 1000v jumping. Called up the local rewinding shop to get some magnet wire and he just told me to come over and take what I need. so I did.

 

[bluewool]

windings and gasoline.

windings and gasoline.

Well, I returned to the winding shop today as I had forgotten the box with the harness there. A guy who has worked there for 35years, I think he's an owner actually was talking with me and I mentioned that my fuel tank had leaked into my crank case and sat for a while.

He said,
"Oh yeah? That would do it. The insulation on older magnet wire does not stand up well to gasoline at all"

so take that how you will.

 

[posplayr]

Well, I returned to the winding shop today as I had forgotten the box with the harness there. A guy who has worked there for 35years, I think he's an owner actually was talking with me and I mentioned that my fuel tank had leaked into my crank case and sat for a while.

He said,
"Oh yeah? That would do it. The insulation on older magnet wire does not stand up well to gasoline at all"

so take that how you will.

I think it is probably good practice to change the stator every 35 years or so whether it needs it or not :-\\\

 

[bluewool]

yeah, with that logic I think it's good practice to replace the entire motorcycle every 35 years whether it needs it or not. :|



All I was saying was simply that if you get gasoline in your crankcase get it out ASAP, alone with bad ground and a crappy harness it'll contribute to destroying your stator.

 

[Steve]

All I was saying was simply that if you get gasoline in your crankcase get it out ASAP, alone with bad ground and a crappy harness it'll contribute to destroying your stator.

Good point. I, for one, had not thought of that possibility.



Now, back to your regularly-scheduled stator rewinding: ... did you find out what gauge wire is standard and what did you get to replace it?

I have a few stators that I would like to try rewinding in different gauges or delta/wye configurations, but don't know what size wire to start with.

.

 

[posplayr]

yeah, with that logic I think it's good practice to replace the entire motorcycle every 35 years whether it needs it or not. :|



All I was saying was simply that if you get gasoline in your crankcase get it out ASAP, alone with bad ground and a crappy harness it'll contribute to destroying your stator.

I guess my joke was to subtle, with new Powder coat and epoxy coatings they should be more tolerant of the gasoline, not that that is something you want to run for any amount of time. So once you change the stator (most require every 35 years) it is not much more of an issue.

Now hydro lock now that can cause some pain

 

[bluewool]

Steve, turns out to be 1.04mm- 1.02mm o.d. which is 18awg. between 31 and 36 turns per pole most were 33. When I removed the windings from my stator some of the varnish came off the poles so I am patching it with what they use if they have an emergency and do not have time to bake it, jb weld. I was a little surprised.

He said on smaller motors/alternators which dissipate heat well, it's excellent.

me - "it's going to be bathed in 70-90c oil."

alfred - "Oh well that's perfect then it's oil cooled, they usually run with internal temperatures of 77c for very small motors up to about 180c for larger motors and alternators."

I going back for a tour of the shop when I have time.

I'll keep you posted,
I took some photos of the meggering process and results.

 

[bluewool]

oh no I got the joke. :|
I guess my deadpan was too dry.

oh yeah Hydrolock, damn near killed a 4bt after washing it. The air box had been installed upside down...filled up the intake with just about enough water to kill it. ug. thanks for reminding me.