Some clarification on stator a/c output please.

[spyug]

As I post here http://www.thegsresources.com/_forum...d.php?t=197020 I am having issues with my 550's charging system. Specifically I am producing over voltage in the 16+volt range. I've been trying to execute the Stator Paper tests and am not making a lot of head way determining where my problems lie. I think ( but am not 100% sure) I have ruled out my r/r ( two of them actually, one stock and one a shindengen with sense wire, show the same values) but suspect my stator.

When testing the legs for A/C voltage I get the most confusing returns. Voltages are different on all three legs and are not level or consistant. They jump around from lows of 20/25 to highs of over 140. The values change in milliseconds it seems, bouncing around from high to low and back again. As I recall from previous tests on other bikes the A/C values are pretty constant and don't change much are they not?

I have checked and double check with two different multimeters and I get the same responses.

With the stator hooked to the sytem sometimes when I bring the probes of the multimeters close to the battery poles (but not even touching) I get similar bouncing readings but more in the range of 12 to 17 volts. This indicates to me the stator is forcing over voltage on the r/r and it is attempting to compensate.

At this point I am contemplating swapping out a spare stator from my parts bike to test but before I go to the bother is there anything that I should check into more closely?

Can anyone shed any light on this or any thoughts?

Cheers friends,
Spyug

[elrico]

Ensure the multi-meter is operating properly,check/replace it's own onboard/internal battery and connections,and/or borrow a known multi-meter somewhere.Check your house ac voltage at a receptacle for expected voltage and a dc battery aa,aaa or whatever is handy.need to confirm multi-meter is good for the troubleshooting task.

[koolaid_kid]

You also need to check the DC voltage that your sense wire is seeing. If it is seeing under voltage (less than your R/R's output) your R/R will output too much DC voltage. If you have a relay mod of some type, its output is a good one to connect to the sense wire. Some even run the sense wire straight to the battery's positive terminal.

[Steve]

When testing the legs for A/C voltage I get the most confusing returns. ...

With the stator hooked to the sytem sometimes when I bring the probes of the multimeters close to the battery poles (but not even touching) I get similar bouncing readings but more in the range of 12 to 17 volts. This indicates to me the stator is forcing over voltage on the r/r and it is attempting to compensate.

I think the first thing to do is to make sure you are testing it correctly.

1. Disconnect all three wires from the stator to the R/R.
2. Hold the three stator wires so you have quick access to their ends, give them imaginary labels of "A", "B" and "C".
3. If possible, have an assistant start the bike and hold engine speed steady. Specs call for readings at 5000 rpm,
but you can get a good guess with speeds over 3000, just hold the same speed to do the following tests.
4. With the engine at (somewhat) proper speed, measure AC volts from A to B, then B to C, then C to A.

What are you doing with your meter probes near the battery poles when you are testing stator output? The battery has nothing to do with that, and at this point, is simply powering the bike so you can test the stator.

.

[Guest]

The stator doesn't force, it is controlled. It can easily do less, if it's damaged. The checks are to determine if it is working up to par. Now if you could crank the bike up to 30,000 rpm that might force a couple of issues. Listen to Steve, and possibly get an analog meter, so you will know what you are looking at.

[spyug]

What are you doing with your meter probes near the battery poles when you are testing stator output?

Steve this is just anecdotal information, not part of the stator testing. I just mentioned it as this was actually the first symptom that I noticed after I had cut out the melted connector and hardwired things together. It seems odd to me that I see this activity at the R/r and then when I do stator testing I see similar activity.

As far as conducting the A/C out put testing of the stator I did it exactly as you outline and the same way I have done it on 4 or possibly 5 different bikes before. What I find confusing is that the voltage shown fluctualtes wildly. In previous tests I always see the voltage at a constant or very close to a constant not occilating up and down as in this case.

With regard to the multimeters, I have used two from different manufacturers but both have apparently worked fine before. One is almost brand new and the other I've used for 5 or 6 years. Any thing I measure i.e. batteries, house voltage, computer power supplies etc. with them records the same voltages.

I'm at a loss to understand what's happening and my question again is, "does stator A/C output voltage vary or stay more or less constant at a fixed r.p.m. ?

I'd just like to get a firm understanding of that please.

Cheers,
spyug

[salty_monk]

In my experience it has always stabilised at a given RPM. Usually 65 - 80v AC at around 5,000 if my memory serves correctly. All legs should measure the same.

If your meter is good then I would suggest that your stator is shot...

[spyug]

Thanks Salty that's what I was thinking. My gut is telling me the stator is wonky so I'll swap it for the one in the parts bike and see what that does for me.

I'll keep you informed.

Cheers,
spyug

[Steve]

... and my question again is, "does stator A/C output voltage vary or stay more or less constant at a fixed r.p.m. ?

Stator voltage should be relatively stable at any given RPM.

It might be different from one bike to another, due to differences in stator windings and magnet strength, but that's for another thread.

Personally, with the flaky readings you are getting, I am betting on a cracked wire in your stator leads. Even though you think you are holding them steady, they are moving ever so slightly, causing erratic readings. The other possibility is intermittent shorting of the windings on the stator itself. Either way, a new stator should fix that.

.

[spyug]

Personally, with the flaky readings you are getting, I am betting on a cracked wire in your stator leads. Even though you think you are holding them steady, they are moving ever so slightly, causing erratic readings. The other possibility is intermittent shorting of the windings on the stator itself. Either way, a new stator should fix that.

Thank you Steve. That's the kind of answer I'm looking for, something that suggests a very plausible cause for the symptoms I'm seeing.

I will now go ahead with the stator swap and hopefully will have this issue sorted.

I'll let you all know.

Cheers,
spyug