brand new stator failed, how could this happen?

[radbrad]

I have an 82 GS 650G, last spring when I bought it, it kept dying on me and I discovered that I had a bad charging system. I got a new stator and RR and it did the trick, though it never charged at over 14V – 13.5 was about all I saw come across the battery and that was enough to keep the battery juiced up.

I used the bike occasionally over the winter, it was just a bit hard to start because of the cold sometimes. Just a couple of weeks ago I took it on trip and rode it for over 8 hours in 2 days, no problems whatsoever – but I haven’t been checking the battery voltage, I figured it was ok since I had a brand new charging system (new battery too, last year).

A couple days ago I changed the oil, rode the bike around a little bit, then checked my battery voltage and found that it was really low, like 12.15. I checked the voltage across the battery while the bike was on and it barely moved when I revved up the bike. Re-charged the battery to 12.9, put it back on, rode it a bit, checked the voltage – 12.28. Checked the AC voltage across the 3 stator wires and I get no more than 10 volts across any pair of wires at high rpms, in fact it barely even goes up a few volts when I rev it. I guess this means my new stator is toast, isn’t it?

My question is, how could I have ruined a stator that was less than 1 year old? I wish I would have checked this during my long trip before I changed the oil, I’m wondering if changing the oil could have something to do with it, since I know these stators are immersed in oil. Is that possible? I think I had an adequate level of oil in the bike during that long trip, could it being overfilled with oil cause the stator to malfunction?

I didn’t do any tests on the RR, but since I know the stator is not putting out, I’m sure it couldn’t have anything to do with this, could it? Also, could a ruined stator cause the RR to break as well?

Thanks
Brad

[posplayr]

Very Simply

Most times stator and R/R do not just fail, they are killed by bad connections.

The R/R needs very good connections to the stator

but

The R/R MUST HAVE to have good connections to an available load.

Based on your voltages you did not clean ALL of your connections between the R/R (+) and the battery (+).

Since you did not do that the current that would normally go to the load is routed back to the stator causing both the R/R and the stator to cook.

Works every time.

Pos

[bonanzadave]

I got a new stator and RR and it did the trick, though it never charged at over 14V – 13.5 was about all I saw come across the battery and that was enough to keep the battery juiced up.

Where did you get these parts ? We have read that some new electronic parts can be bad out of the box. Never getting over 14vdc may have been an indicator day one. How is the wiring and connectors between the two ?

[radbrad]

I got the stator and RR from www.rmstator.com, and had a local bike shop install the parts for me. I don't know how to install this stuff myself, I trusted the mechanic to properly connect the parts. I sanded all the connections I could get to, under the seat and above the battery myself last year. This bike mechanic told me he has seen old bikes like this not get the high charging voltage they might have once got even with new parts.

[posplayr]

Well it might be a little late, but the key is to make sure what the actual voltage drops between:

battery (+) and R/R (+) is less than 0.5V at 4000 RPM and preferably 0.25V

battery (-) and R/R (-) is less than 0.5V at 4000 RPM and preferably 0.25V

You probably got the grounds OK, but without measuring the above you cant be certain.

I took a non working bike with bad connections and simply by changing connections got it to charge properly and there was nothing wrong with the parts.

If you tested the stator open circuit (with the R/R disconnected) and you only have 10V you gotta go back in and do that first. The R/R might still be OK but you need to do the stator first.

What the mechanic is saying about old bikes not charging as well, is more than likely old connections more than old bikes. Suzuki say it should charge between 14.0-15.5V at 4000 RPM.

Voltage at Idle of 1200-1500 RPM should be about 12.7-13.2V depending upon RPM.

[tkent02]

It's always the connections.

[BassCliff]

Hi Mr. radbrad,

It seems your very first posts back in July of 2008 were about your charging system. These bikes need to have every electrical connection and ground, from the headlight bucket to the tail light - including the fusebox and ignition switch, clean and corrosion-free. Look in the Electrical section of the Odd and Ends page on my website for suggestions.

My RMStator stator failed during the warranty period. They replaced it, no charge. While I was waiting for RMStator I bought an Electrosport part. It failed just after the warranty expired. I cleaned all of my electrical connections again and put the RMStator part on. So far, so good.

Get yourself a fine wire brush, some contact cleaner, and clean that wiring harness. Look on my site for guides to help you replace things like stators and r/r units. I strongly urge you to work on your own bike. It will make both of you happy. Keep us informed.

Thank you for your indulgence,

BassCliff

[radbrad]

Yes, BassCliff, I never followed you're original advice to clean ALL connections, bucket to break light, but wouldn't the connections between the stator and RR, then the RR to the battery be the ONLY connections that could possibly affect the charging?

I wish I had more time do things like clean all connections and learn how to install my own stator. You have some great directions on how to do that on your web page, but I'm still afraid I'd mess something up. I think I'll give it a shot though.

Who do you think sells the best stators? If I need a new RR I was gonna get the Honda one from that one person who sells them on here.

It sound like you guys think connections are definitely it though, thanks for your advice.

Brad

[jjmaag]

Check the voltage drops from the R/R to the battery, positive and negative. I had the same voltages after installing a new R/R and stator and I found a large drop on the positive side thru the fuse panel. Also make sure to put a ground wire from the R/R driect to the battery.

[BassCliff]

Yes, BassCliff, I never followed you're original advice to clean ALL connections, bucket to break light, but wouldn't the connections between the stator and RR, then the RR to the battery be the ONLY connections that could possibly affect the charging?

Hi Mr. radbrad,

Yes, the connections most affecting the charging system are the r/r connections, the stator connections, the fuse box connections, and the battery connections including the engine ground. Bad connections anywhere in the wiring harness add resistance, heat, and stress to the system. Corrosion can cause your blinkers not to blink, can cause a weak spark to your plugs, all kinds of weird things.

From the world-famous Stator Papers:

Stator Papers V - Why do charging systems on bikes fail so often at all?
This article goes into the main reason of failing stators, main fuses, regulators/rectifiers and other expensive electrics: improper conductivity.

Thank you for your indulgence,

BassCliff

[barsnake]

From what I've experienced..

The dreaded Suzuki disease! I'm currently running the factory unit with a slight modification. I added a load resistor across the battery to dissipate some of the energy when the battery water level is low or the headlight is off. The Suzuki stator is a 3 phase generator, if the headlight is off; it tries to dump the additional energy onto the battery. If the battery is in poor shape and can’t receive it, the wires (check connectors) and the R/R overheat. It's real important to have a good battery!! The Gs's have a habit of over-charging the battery. The water level has to be checked and maintained frequently or the charging system will fail. The newer components are better then the originals but they too can fail.

Good luck!

[posplayr]

Fruit loops

Radbrad

here is a post that focus directly on the charging system power and grounds connections and how to make it bullet proof.

High Performance Power and Grounding

http://www.thegsresources.com/_forum/showthread.php?t=140109

Barsnake

This post discusses the GS charging system in a theoretical perspective and describes the various current paths relevant to the charging system. Generally any current dumping in shorting the stator which tends to heat the stator as well as the R/R which is doing the shorting.

I'm still looking for a mechanism for over charging. I know it exists but it may be a design feature of the OEM R/R alone.

What resistor Resistance and wattage do you have across your battery?

Ground Loops

This first post was edited to bring the primary analysis , summary and test method to the top. Everything following that has been discussed that is relevant to the analysis has be added here.

GS Power and Grounding Scheme

http://www.thegsresources.com/_forum/showthread.php?t=139115

Pos

[Steve]

Something about this statement makes me nervous:

I added a load resistor across the battery to dissipate some of the energy when the battery water level is low or the headlight is off.

Unless you have some way of controlling that resistor, simply adding a resistor across a battery is a guaranteed way to simply discharge the battery. Depending on the resistance involved, the process might take a while, but it will be complete.

A properly-running charging system should not need anything beyond what came stock on the bike to do a proper job of charging the battery.

.

[barsnake]

I wired it from positive to ground only when the power is turned on so it doesn't drain the battery when the bike is off. They used a similar setup with my 71 TS250. The resistor was mounted under the battery. It kept the battery from over-charging when the headlight was off during high revs. There was no voltage regulator on that bike just a rectifier so the battery would over-charge without the resistor. It's worked fine on my 78GS1000 for many years. I just copied the idea because my GS was over-charging all the time, especially if I went on a long highway trip.

[barsnake]

I just checked the connections and values of the resistors. I used two 50 ohm 50 watt wire-wound ceramic resistors in parrallel. I attached one end to the negative terminal of the battery and the positive to the 15A mains fuse.