Stator Question

[Guest]

Hey everyone,

I decided to test my stator the other day and found out that no matter what the RPM was, I was only getting 12.3V through the battery. I read through the stator tests and found that I was getting 0.4Ω with each combination of wires tested. I decided that it probably couldn't hurt to pull the stator and take a look.

The condition of the stator looked good to me except for one of the end plates. It looks like the contacts on the end plate were worn off.

I wanted to know if that's normal, if not, if there's any way to fix it or is the only remedy to replace the whole stator?

Thanks,

Chris

[flyingace]

Hey everyone,

I decided to test my stator the other day and found out that no matter what the RPM was, I was only getting 12.3V through the battery. I read through the stator tests and found that I was getting 0.4Ω with each combination of wires tested. I decided that it probably couldn't hurt to pull the stator and take a look.

The condition of the stator looked good to me except for one of the end plates. It looks like the contacts on the end plate were worn off.

I wanted to know if that's normal, if not, if there's any way to fix it or is the only remedy to replace the whole stator?

Thanks,

Chris

You can't go by the appearance of the stator. It needs to be tested with the bike running.
I find the easiest way to test charging problems is to read the AC voltage where the wires enter the R/R. If cuts the problem in half. If you have adequate AC voltage there from the stator, you can assume the problem is upstream - R/R or wiring to the battery.

[BassCliff]

Hi Mr. cp___32,

I never get tired of saying it. Please check and clean every connection and ground on the entire wiring harness, from headlight bucket to tail light, including the fusebox and ignition switch. You'll be glad you did. Corrosion causes extra resistance. Have you tried moving the ground wire on the r/r unit directly to the negative battery terminal? This will overcome a lousy frame ground return path.

The passive tests for the stator can tell you if your stator is bad, but they can't tell you if your stator is good. Like Mr. flyingace suggests, test the stator on the bike. Follow the Stator Papers completely and check the AC output of each stator leg.

If the stator is bad then replacement is the quickest way to get back on the road. Several members have followed the instructions (in the garage section) for rewinding their stator and have had success. It's a little tedious and time-consuming but you'll have a new stator for less than a third the price of a new one. Keep us informed.

Thank you for your indulgence,

BassCliff

[cp___32]

Thanks for the input.
Like I said, I did visit the stator papers and I did do some tests while the stator was on the bike and found that the resistance was just under the low side for the resistance limits, and when I had the bike running I wasn't getting an increase in voltage over what was already in the battery to begin with.
I was planning on trying to rewind the stator, but instead of wasting my time trying to repair a part with an obvious defect in it, (and since this is the first and only stator I've ever looked at in my life) I wanted to make sure that section that LOOKS like it's been worn isn't going to effect the performace of the stator even if I did rewind it.
I don't know enough to know if the stator is supposed to look like that, but considering out of the 18 separate lobes on the stator, there is only 1 that looks different from the rest, I just wanted to ask those with a little more experience if that's normal or if it's an obvious problem.

[BassCliff]

Hi,

That little worn spot won't affect the operation of the stator. The only thing I can think of that would cause that worn spot would be contact with the rotor magnets. Make sure this doesn't happen when you reassemble. What does the rotor look like? The AC is generated by the magnets rotating around the windings. The poles just hold the windings, but they shouldn't come in contact with the rotor.

When performing the active tests on the stator, it must be disconnected from the r/r unit. Your multimeter must be set to read AC voltage between the stator legs. Forgive me if I state the obvious. I'm just trying to be thorough.

If you haven't yet, feel free to visit my website. You'll find maintenance guides with lots of pictures for most of the regular maintenance necessary on our GS bikes.


Thank you for your indulgence,

BassCliff

[Redman]

Some comments (some similar to other postings above) :

- that wear area is a bit of a concern, but will not effect functionality of the stator (doesnt effect the coils of wire).

- THe ohm test is only to see if stator is not compltly open (disconnected) or if its not complety shorted out (zero ohms). Being a little off is not a definate determination that it is bad.

- The better test that tells you more is the open circuit voltage test, with stator disonnected from the R/R, bike running at mid rpms, and measure AC volts output from the stator (not the DC output from R/R to the battery). BUt you have it taken apart now. Would have to put back together to test this. BUt you probably dont want to spend $100+ if you dont need to, either.
I would say that you have not provided any evidence yet that the stator needs to be replaced.
First lets check out the stator better.

- The stator is only one of 3 major parts of the charging system. The stator could be good and you could still see the problem you describe (low voltage at battery). Other major componet is the regulator/rectifyer ("R/R"), which could also cause the symptoms you are seeing.

- The 3 parts of the charging system: 1)The stator is to produce AC voltage that goes to the R/R. 2) The R/R is to convert it to DC and regulate it to about the 13.5vdc. 3) I would concider the battery and all the conenctions in wiring to be the 3rd componet of the charging system.

.