Me running the Stator Papers with pictures

[brienc]

Hi,

This is my second post here. I have a 1982 GS750T (I put the wrong year in the first post). I am currently working through some electrical issues, and wanted to document how I went about troubleshooting using the Stator Papers.

I will try to post the pictures that I took to help the other newbies that might be out there, and to solicit any tips folks have about my current situation.

I replaced my battery with a new AGM model last weekend, and gave it a full charge. Bike is starting well right now.


Here is the DC voltage across the bottom terminals of the fuse block. I measured there because it has read the same as the battery posts in my past tests and I hadn't yet gone through the trouble of taking out the air box to rech the battery directly. Even though the bike has been sitting for a few days, it was still reading higher than normal at 17.3V.



With the key on it dropped to 15.7V.



At idle, it jumped up to 20V.



At 4000 RPM, it went even higher to 22.8V.



The first test I ran was one described in my Clymer service manual, that directed me to measure the voltage from the positive terminal on the starter relay to a ground point at 5000 rpm. That gave me 18.8V, the book says if it is higher than 15.5V to replace the regulator/rectifier (RR). At tom203's suggestion I wanted to check the connections as directed in the Stator Papers.



To get at the battery, one has to take out the air filter box. The only way I am able to do that is my removing the bolts from the rear of the fuel tank and the bracket they attach to. Then I loosen the forward clamp of the short hose at the front of the airbox, then its a tight fit to lift the tank & bracket up and rotate the airbox up and out.


This was the first test to check the connection between the red lead coming out of the RR and the positive battery terminal. Mine measured 0.08V not too bad.


Next looking at the ground point with it still attached to the frame. Mine was screwed in behind the fuse block. That voltage reading was jumping around 0.15-0.22V, a little on the high side. That same lead was long enough to go directly to the negative post of the battery. So I changed that over.

[brienc]

continued...


When I looked closer at the Stator connectors, I noticed they were pretty black and had melted the plastic covers. Here is what they looked like after cutting those off.



Next I measured the resistance between each pair of the stator outputs. They all measured about 1 ohm. I didn't get a picture of the next test, but measuring the resistance from the stator wires to a ground read "1." which I think is infinite on my multimeter.


The next step is to check the AC voltage output of the stator with the engine running at 5000 rpm, each of mine read about 86VAC.


The next test I am not that sure about. I think I got about 1.0V drop when doing a diode check from the Red lead to the yellow output (which would be a failure). The other two showed "1." which I am not sure is bigger or no connection? So I think that means my RR is indeed bad.



I pressed on with the tests, here it looks like when checking from the RR inputs (red probe to the yellow wires) to the red RR output. That was showing about 0.6V with all three inputs. Again I missed taking a picture of the next test, but I think when connecting the black lead to the RR black ground wire to the yellow inputs lines with the red leads got the same "1." reading.


Lastly looking at the connection from the RR ground (red lead) to the yellow RR inputs, read about 0.6V.

So, now I am asking for the advice of those of you that have read this far. Should my next step should be to purchase a new RR? I am in the process of cleaning off the stator connections and putting new wire covers. Then I will see if it is still over charging the battery.

Also just to verify. As has been mentioned several times here, it is a good idea to connect up the white/green stator wire right up to the white/red line on the RR? That will take out the phantom headlight loop, right?

Thanks for any advice.

Brien

[Steel Toed Tank]

I have read this far, and have done the same tests for the same issues on the same bike as you have.

Your RR is shot, lucky for you the stator is still good.
When my RR went it took out one leg of the stator with it (or maybe the other way around)

Don't buy any of the RR's listed on that link you posted.
What you want is a Shindengen one off a honda or kawasaki.
Something like this one.

If you search or check Basscliffs site you will found out more than you ever wanted to know about why your old one failed, why the Shindengen ones are better, how too install it on a suzuki, whats even better than those and everything else you could imagine.

I've put 10,000kms on my T since replacing the RR with an old used Shindengen one from a '80 KZ1000 and everything has been great since.

Tank

[Steve]

All your tests look pretty well-done, and I think you found your culprit, a bad diode in the R/R.

Just to clarify a bit, there are a total of 12 tests that need to be made when testing the diodes.

If your meter has a diode test function use it, otherwise use the Ohms setting.

Red meter lead on red R/R wire, black meter lead to each of the three stator wires.
You should get a -1- or OL reading on all three wires.

Reverse your meter leads, put the black meter lead on the red R/R wire, red meter lead to each of the stator wires.
You should get a low reading, about 0.5 to 0.8 on all three wires.

Move the black meter lead to the R/R ground wire (probably a black wire), red lead to each of the stator wires.
You should get a -1- or OL reading on all three wires.

Reverse your meter leads, put the red meter lead on the black R/R wire, black meter lead to each of the stator wires.
You should get a low reading, about 0.5 to 0.8 on all three wires.

Note that six of these readings will give you your "out of range" indication, whether it's -1- or OL, and six will give you a low number.
If there is ANY deviation from that, your R/R is toast.

.

[brienc]

Thanks guys

I appreciate the advice about the Honda R/R and the re-assurance and explanation of the rectifier diode tests. Off to e-bay!

[BassCliff]

Greetings and Salutations!!

Hi Mr. brienc,

Check the electrical section and the testing/repair guides on my little website. They should help. New let's get to the S.W.A.G.

If you are here you probably have a 30 year old motorcycle that needs about 20 years worth of maintenance. You'll find all kinds of helpful tips, procedures, manuals, etc, in the links below. Let's get started.

Let me dump a TON of information on you and share some GS lovin'.

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", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. 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

[81ZUKI75]

Since I'm no "Sparky" , I decided to go with a full-on kit from roadstercycle

http://www.roadstercycle.com/

It's HUGE compared to the original...



But it will fit. It's very tight and requires a new hole for mounting to the existing plate...

OLD:



NEW:



I'm sure one could make it prettier than I did

good luck.

[chef1366]

Are you sure your meter is good?
Seems high on the no load battery test.

[brienc]

well that didn't work

I got the used RR that I purchased from ebay, a Shindengen SH535 A-12 unit.

I diode tested it per Test Phase C of the Stator Papers (and as Steve described above) and it looked good.

I installed it using these instructions using the green-orange brake light feed for the sense wire (which was orange on my RR).

I had the battery disconnected for about a week it was still at 15.5V. When connecting up and turning on the key it dropped at 14.0 or so. The bike started up on the third try, but any where from idle to 5000 RPM, it was reading 17.7V across the battery terminals, looks like it is still over-charging.

I hear what you are saying chef, I know this is a cheap multimeter I am using, but it is still showing accurate measurements with other items around the house.

Besides from starting over and running the stator papers again, does anyone have an idea of what my issue could be or what I can try next?

Thanks,

Brien

[JayWB]

I really can't imagine a battery still reading 15.5 volts after a week of inactivity. It just doesn't happen.

Can you go out and check the battery voltage of a car battery with it? With the car not running it should show about 12 - 12.25 volts. Same with your motorcycle battery. 15 volts plus and your meter is lying to you.

That's my bet.

[brienc]

I really can't imagine a battery still reading 15.5 volts after a week of inactivity. It just doesn't happen.

Can you go out and check the battery voltage of a car battery with it? With the car not running it should show about 12 - 12.25 volts. Same with your motorcycle battery. 15 volts plus and your meter is lying to you.

That's my bet.

Ok thanks (and to chef), I have another MM on order. I will check it out then.