Bad Stator - confirm?

[allojohn]

any progress?

Good question, actually I'm not sure.

I replaced the stator (Electrosport) and did the quick test.

Headlamp OFF
Key off 12.51
Key on 12.06
Idle 12.60
2,500 rpm 14.30
5,000 rpm 14.30
Key off 12.90

Headlamp ON
Key off 12.65
Key on 11.90
Idle 12.20
2,500 rpm 12.60

Got called away and didn't complete.

I'm beginning to think I've screwed some wiring after doing relay mods on the coils & Dyna ignition and the horn.

[posplayr]

The bike has been completely rebuilt (2011-2012) and all connections have been cleaned. The R/R is a new Electrosport and is connected directly to the battery which is also new.

When I finished the rebuild in March I checked the charging system and everything was in order. This issue has arisen in the last couple of weeks.

I will continue with testing but I'm close to replacing the stator - hell, it is 34 years old and while testing the stator has not been definitive it is the likely cause of the problem.

any progress?

[allojohn]

Is your R/R (+) wired to the battery or still stock? Have you checked the condition of or cleaned the R/R connections to the stator and wiring harness?

It's apparent the headlight is pulling down the voltage because the R/R is unable to supply enough current. Resistance in the system (wiring, connection, or component) or lack of stator to output rated current is likely the issue.

Also how old is the battery?

The bike has been completely rebuilt (2011-2012) and all connections have been cleaned. The R/R is a new Electrosport and is connected directly to the battery which is also new.

When I finished the rebuild in March I checked the charging system and everything was in order. This issue has arisen in the last couple of weeks.

I will continue with testing but I'm close to replacing the stator - hell, it is 34 years old and while testing the stator has not been definitive it is the likely cause of the problem.

Is your R/R (+) wired to the battery or still stock? Have you checked the condition of or cleaned the R/R connections to the stator and wiring harness?

It's apparent the headlight is pulling down the voltage because the R/R is unable to supply enough current. Resistance in the system (wiring, connection, or component) or lack of stator to output rated current is likely the issue.

Also how old is the battery?

[allojohn]

The dummy load was the best I could come up with without having a megger.

Sounds like something my daughter would say - "I'm having a megger!"
Then I looked it up.

I think I'll "have a megger" if I do one more test involving stator legs! LOL

[posplayr]

@posplayr - I did as you suggested and measured AC volts on the stator legs to ground, lights on and lights off. Got the same result both times about 8 volts. This was at idle. Do I need to do it at 5,000 rpm?

Also, when performing step 2 and 3 (voltage drop) the drop we speak of is the meter reading at 5,000 rpm, correct?

Sorry but I'm starting to realize that the leg to ground tests will only work if the R/R were isolated from ground which it can not be. You would need to use an isolated dummy load. I think I did a thread on this.

So never mind on that last test. wont work. That is why you are getting the same answer.

http://www.thegsresources.com/_forum/showthread.php?t=174130&highlight=phase

As you will see in the thread above I spent quite a bit of time looking for better tests when a stator is intermittent. The dummy load was the best I could come up with without having a megger.

[allojohn]

@posplayr - I did as you suggested and measured AC volts on the stator legs to ground, lights on and lights off. Got the same result both times about 8 volts. This was at idle. Do I need to do it at 5,000 rpm?

Also, when performing step 2 and 3 (voltage drop) the drop we speak of is the meter reading at 5,000 rpm, correct?

[posplayr]

I disconnected the voltmeter on my dash and did the "quick test" again, headlamp off and headlamp on.

Headlamp off

Key off - 12.48
Key on - 12.05
Idle - 12.55
2,500 - 13.80
5,000 - 13.95
Key off - 12.90

Battery is a little low but it charges going from 12.48V to 12.90V after a short run.

Headlamp on

Key off - 12.73
Key on - 12.00
Idle - 12.14
2,500 - 12.45
5,000 - 12.55
Key off - 12.38

Now it is not charging with the lights on. The R/R probably did not suddenly die. More than likely the stator is going out at the higher load current.

You could confirm this by measuring the AC voltage between one of the legs of your stator and ground with lights on and then with lights off. I suspect that with lights off you get zero but with lights on you get a reading indicating the insulation is breaking down at higher output current (to the lights).




I've had enough for today, I'll take another look later in the week.

Thanks for your help and patience guys, it is much appreciated.

.................

I should mention I'm being careful with my wording. As we know when the lights are off there is less current flow out of the R/R but more current flow in the shunted stator. So the current through the stator actually goes down with the lights on. So how does that make the stator fail? The only thing I can think of is that the peak voltage on the stator is higher when it is not shorted and the higher voltage is causing the stator insulation to break down at some point. So that would be at least one theory of how the breakdown is flowing whether or not the lights are switched on.

[allojohn]

OK So I assume your lights are also bright when you have them on?

Yes.

I assume also that you have followed the guidance for cleaning and connecting your grounds. You have a wire from

• • R/R(-) to battery
  • R/R(-) to frame
  
  

Yes.

Have you measured the Phase A results?

No. But I will later.

Thanks man - you are a great help!

[allojohn]

I disconnected the voltmeter on my dash and did the "quick test" again, headlamp off and headlamp on.

Headlamp off

Key off - 12.48
Key on - 12.05
Idle - 12.55
2,500 - 13.80
5,000 - 13.95
Key off - 12.90

Headlamp on

Key off - 12.73
Key on - 12.00
Idle - 12.14
2,500 - 12.45
5,000 - 12.55
Key off - 12.38

I've had enough for today, I'll take another look later in the week.

Thanks for your help and patience guys, it is much appreciated.

[allojohn]

Your voltage readings, both AC and DC, seem to change every time you test them.

I said I wasn't very good at this.

I think the first thing I'd do if I were you would be to remove the R/R ground, clean it thoroughly, and connect it DIRECTLY to the battery negative, not to the frame or engine.

Yep, already done that.

In my first post I mentioned I installed a voltmeter on the dash. I think I'll remove it to see if that has caused my problems. I'm in the headlight bucket now......

[posplayr]

Yes Sir, headlamp loop removed!

OK So I assume your lights are also bright when you have them on?




I assume also that you have followed the guidance for cleaning and connecting your grounds. You have a wire from

• • R/R(-) to battery
  • R/R(-) to frame

Have you measured the Phase A results?


I am starting to suspect the stator again, but want to confirm the voltages from the Phase A tests. Focus on those tests now. Do the tests with the headlamp OFF.


This is a bit of a guess right now but it could be the stator windings are OK when you don't have the headlamp on, but when you add that additional load the extra current causes the winding to break down. It is intermittent/marginal right now but will eventually fail hard.

Your voltage readings, both AC and DC, seem to change every time you test them.

It's hard to get a read on what's going on when everything changes all the time. I think the first thing I'd do if I were you would be to remove the R/R ground, clean it thoroughly, and connect it DIRECTLY to the battery negative, not to the frame or engine.

If that doesn't resolve your charging problem I'd build a dummy load out of light bulbs, disconnect the R/R from the stator and plug the dummy load in. That way you can see once and for all if the stator is operating normally.

[allojohn]

We it does sound like it is charging pretty well. Wonder what is going on with the headlight? Did you disconnect the headlamp loop? In other words the 3 stator wires go directly to the R/R.

Yes Sir, headlamp loop removed!

[posplayr]

Just to add to the confusion I turned the headlight off and and now get 13.80 @ 2,500 rpm. and 14.00 @ 5,000 rpm.

My head is spinning - I'm going for a cup of tea........

We it does sound like it is charging pretty well. Wonder what is going on with the headlight? Did you disconnect the headlamp loop? In other words the 3 stator wires go directly to the R/R.