1981 GS650G R/R replacement questions

[Suzuki5724]

Hi folks,

Long time fan of this forum, but first time posting.

I was driving along when I noticed some smoke coming from under my seat.

I pulled over and discovered that my R/R was totally fried. As the diodes burned they had melted a hole (now patched) in my air box and melted a bit of the insulation on a few wires.

I ordered a new r/r that is supposed to fit but it has 4-contacts inside the quick connect while the one I removed only had three contacts inside.



Some questions:
1) Is that extra contact important? The three yellow wires leaving the RR are the same positions as the three on the original plug. The 4th is a brown wire. Can I just plug it in to the male side that is still on the bike?

2) Do I just run the black eyelet to the negative battery terminal?

3) Does the RR itself need to be affixed to the frame for grounding or can I mount it securely but electrically isolated from the frame?

4) What are the odds that my stator is fried? Can I try the new R/R out without replacing the stator or is that asking for trouble?

5) I'm new here so forgive my ignorance but is this forum a place I could connect with someone in my area (Cleveland, OH) who might accept a 6-pack or something in exchange for some hands-on help?

I've been riding the bike for almost a decade and it's been really great, but I knew it was only a matter of time before the electrical rats nest under seat would have to be dealt with. I suppose that time is now.

Thanks y'all.

 

[Redman]

Welcome to THeGSR.

I had a 82 650G for 20+ years, but I dont really know where the r/r was mounted. I think it was on bottom of the battery box, but am not really sure. So i dont understand about the r/r burning a hole in the air box.

....
(more later)

.
.
.

Some questions:
1) Is that extra contact important? The three yellow wires leaving the RR are the same positions as the three on the original plug. The 4th is a brown wire. Can I just plug it in to the male side that is still on the bike?

2) Do I just run the black eyelet to the negative battery terminal?

3) Does the RR itself need to be affixed to the frame for grounding or can I mount it securely but electrically isolated from the frame?

4) What are the odds that my stator is fried? Can I try the new R/R out without replacing the stator or is that asking for trouble?

5) I'm new here so forgive my ignorance but is this forum a place I could connect with someone in my area (Cleveland, OH) who might accept a 6-pack or something in exchange for some hands-on help?

.

1) the 3 yelow wires would be the a/c input (3 phase A/C from the stator).
THe 4th wire should be the rectified and regulated DC from the R/R. I am surprise that is not a red wire. Makes me want to ask: What R/R is that, where did you get it?

2) blacvk eyelet. Yes, the negitive-ground wire. Usally grounded at the mounting bolt of the solenoid, andi si usally a black/white ground wire from the wirning harness there also (since thebattery box is not grounded by its mounting to the frame). SOmetimjes are problems with that wire, so most folks add there owun wire from there to batt negitive. And speaking of that wire, the negitive.... sometimes, depending on how the r/r fails, it dumps a lot of current down that wire, and melts that wire and wires nearby (which sounds similar to what you said happend to you).

3) R/R mounting ground.
R/R does not get its ground from its mounting. No, the case of the r/r does not need to be electrically grounded, But is good to be bolted to something, just for a little bit of heat sink.
Now, the black wire, that does need to be grounded.

4) Stator
bad r/r can take out the stator yes. Good that you ask.
Here is where you need a volt meter (since is difficult to troubleshoot electrical systems with your eyeballs). Leave r/r disconnected. RUn engine at about 4000 rpm, measure the AC volt output on each pair of two stator wires. That will be 3 readings. Each SHould be about 70 VAC. And from each stator wire to ground, should be about zero volts. Also, with engine not running, check ohms, each lead to ground, should be infinite ohms. THose tests will not tell you the stator is absolutley good, full strength. Could test good, yet be near close to failure. But the test will tell you if it has failed already.
You have a 35+ year old bike, you should have a volt meter. You have an 80s GS, you need a volt meter.

5) are several members in various places around Ohio. DOnt know might be close to Cleveland. But I do know one side of Cleveland is quite a distance from the other side of Clevelend (I used to be in Euclid). Maybe you could state which part of Cleveland.

 

[Buffalo Bill]

You can test your stator without removing it, just by checking the 3 leads with a multi meter.
Please read a service manual for details.

 

[Redman]

Other thing: You will probably get recomendations from fine folk here that this would be a good opportunity to change to a different type of R/R (series). Which would be a good idea.

But we can see you are just tryiing to swap out the existing R/R with comparable R/R so the wiring/connector match. Okay.

 

[tom203]

Something fishy here.... My 650L has the r/r and ignitor mounted to a plate which in turn is mounted to the bottom of airbox- it stands off abit , so I don't see how it could burn holes in airbox- Suzuki wiring is wimpy , the wires should just melt or more likely the 15 main fuse should just blow.
The stock r/r had a 4 way connector , just like the replacement in your picture. Not sure how your original 3 way connector was made to work, but folks can get real creative with wiring "solutions".
As mentioned, this is the time to upgrade the charging system....I did mine 6 years ago and have enjoyed charging bliss.

 

[Redman]

.... while the one I removed only had three contacts inside.
.
.

Ah, I didnt catch that. But that still doesnt releeve my wondering about what R/R you got.


All I can say is that the wires for the R/R: three wires will be for the stator, aftermarket are usally yellow, stock is three different codes.
One, usally red, will be the DC+ out from the R/R to the main wiring positive, usally connects into the wiring harness between the main fuse and the ignition switch.
And one, black is DC-.

Did your original connector look a bit melted. I wonder if it did have the 4th connector (DC+) but someone pulled it out to make a reapired conection outside of the connector block.
Oh, say ... the r/r you took out, must have had the 3 wires in the connector, the ground wire, and.... and... where was the other wire.....?

Other thing I can say is that the 650s (G and GL and E) have the most design differences from all the other GSs of that era. So when folks talk from thier expereince with most GSes, there could be some difference on the 650s.

 

[Steve]

Up until about a week ago, I could have walked out to my shop and taken a look at an '81 650G to report exactly what was where.
Alas, the owner has it back at his place, so I don't have it available.

It has been mentioned that you can test your stator. Find the connector with three wires that comes from the stator. That is likely the one that you are questioning about the replacement R/R having four wires. With nothing but an AC voltmeter connected to those stator wires, measure the voltage at each pair of wires with the engine runnig at 5000 RPM. Expected voltage is 75-90, but it is more important that they match, rather than the absolute number, as long as the number is close to that range.

If the stator checks out OK, please consider getting another R/R. The current forum favorite comes from a Polaris side-by-side or a SeaDoo watercraft. It is a model SH775 by Shindengen. New ones have gotten rather expensive, we usually do some looking and find a good used one for about $50. Will be happy to send you a couple links to eBay auctions, as there are way too many fake units that look like the SH775, but are considerably inferior.

It appears that the fourth wire in your new R/R might be the positive output. The three yellow wires do come from the stator, the brown one would be connected to your red wire. The black wire with the ring terminal is the ground. We tend to advocate a "Single Point Ground", where all the grounds come together, including the R/R, then one wire goes from there to the battery negative terminal. Yeah, you could use the battery terminal as your SPG, but you would have a stack of over half a dozen wires to keep track of when you have to remove the battery for anything. I prefer just two wires at the negative terminal (the SPG wire and the large one that goes to the back of the engine) and just one wire on the positive terminal. That wire feeds the starter solenoid, I take all my positive feeds from the solenoid.

.