'82 GS 750TZ-Lets get this charging system sorted

[Rich82GS750TZ]

The bike never charged well, if at all. Since I've started lurking and joined GSR a few weeks ago, I have learned SO much about the charging system on my bike. And I know whatever issues I come up with, this community will help me get trough it as long as I follow the steps and don't try to shortccut anything. I really want to start enjoying owning this bike. Up to this point, I've just sort of tolerated its ****y attitude. That's about to change.
IMG_3678.jpg

Bike still has original factory stator, R/R, headlamp loop is intact. Ground wires all over the place just like it came from the factory. I intend to fix whatever needs fixing.
I bought myself a voltmeter an am using one for the first time. So please, don't be too harsh if I do something stupid.
I've put in a new battery and have done the Quick test :

1) Key Off - 12.62 VDC
2) Key On - 12.15 VDC
3) idle 1500 RPM -12.09 VDC
4) at 2500 RPM - 12.08 VDC
5) at 5000 RPM - 12.05 VDC
6) Key off - 12.38 VDC
Not Good, I know.

So, I disconnected the stator wires and had my son hold the throttle at 5000. Each leg read right around 89-90 VAC. Turned the bike off and tested continuity from each leg to engine case and got no reading. So that's all good news for the stator, right?

I've found and ordered this used SH775 R/R from eBay for $40. is has SH775AA stamped on the top. It's dirty but I'm hoping its OK.
IMG_3679.jpg
I've ordered this wiring plug kit for it from amazon. Should be the right one:

https://www.amazon.com/gp/product/B00UI4L0IE/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

I've ordered this crimping tool so I can properly make the connections I need to/from the new(used) R/R:

https://www.amazon.com/gp/product/B01M1YK5FM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I'm going to work on cleaning up the grounds to a SPG. Then I'll see where I stand.

If anything I've done up to this point doesn't seem right. Please, set me straight.
I'm looking forward to learning more and contributing what I can to this awesome forum, and to finally enjoying my GS.

[tom203]

"So, I disconned the stator wires and had my son hold the throttle at 5000. Each leg read right around 89-90 VAC. Turned the bike off and tested continuity from each leg to engine case and got no reading. So that's all good news for the stator, right?"

Get your son back and repeat , but do it differently with revs @ 5000
With stator leads disconnected from r/r, and multimeter set on 200 VAC (or same scale that you measure house outlet with) measure stator lead to lead and note readings. Then ,while still running,measure from any (or all) stator lead to a good bike ground: you want to see a very low reading here...0 would be ideal. This is a crude test of stator's isolation from ground.

[Steve]

I agree with Tom, you also need to do the leg-to-ground test. Otherwise, it all sounds good, but you really should eliminate the "headlight loop" when you install the new R/R.

.

[Rich82GS750TZ]

Thanks Tom. Just so I’m clear on the voltmeter setting for this test. Here’s a pick of my meter. Is this the right setting?
0470BC84-3D3B-43D6-BD76-9AEA7B38C5E2.jpg

Thanks Steve. I plan to eliminate the "headlight loop" when I install the new (used) SH775 RR, hopefully this weekend. Is it OK to just let those wires hang? Do I even need to tape up the cut ends? Measuring voltage for each stator leg to ground, should the bike be a running at 5000 RPM?

[Redman]

Rich,

Again, WELCOME to GSR.

Let me congratulate you on one of the best, if not THE best, newbie post.
Most newbie post about charging system, well, first of all they dont know its a charging system problem, but describe in detail where they rode to, and how long they were there, and what sound it made when it wouldnt start..... and so on.

Your quick test shows the battery to be fairly good.
And shows the charging system not charging at all, like it doesnt even exisist.

Yes, your stator diagnosis sounds good. You took got volt readings leg to leg, and ohm reading to ground, which is fairly conclusive of good stator. But the volt readings leg to ground will really complete everthing for the stator.

Unless your R/R is not connected, or not grounded, yah, I would conclude it needs to be replacved.
Speaking of which, do check to verify if the R/R black wire is connected to the battery box (solenoid mounting bolt)... AND if it is, check that the battery box is grounded by a blk/wht wire from the wiring harness, and that that wire is in fact a ground wire (continuity to battery - ). The battery box may not be well grounded by its mounting to the frame, so need to have a goruind wire tun to it..... Which, no that I think of it, if it was not, the starter solenoid would not be gorunded either and you would be asking about that......

[fastbysuzuki]

Thanks Tom. Just so I’m clear on the voltmeter setting for this test. Here’s a pick of my meter. Is this the right setting?
[ATTACH=CONFIG]55442[/ATTACH]

Thanks Steve. I plan to eliminate the "headlight loop" when I install the new (used) SH775 RR, hopefully this weekend. Is it OK to just let those wires hang? Do I even need to tape up the cut ends? Measuring voltage for each stator leg to ground, should the bike be a running at 5000 RPM?

your multimeter setting is correct at 200v AC. Yes measuring stator leg to leg should be done at 5000rpm.

headlight loop can be left tucked away and taped up if you like.

[posplayr]

Thanks Tom. Just so I’m clear on the voltmeter setting for this test. Here’s a pick of my meter. Is this the right setting?
[ATTACH=CONFIG]55442[/ATTACH]

Thanks Steve. I plan to eliminate the "headlight loop" when I install the new (used) SH775 RR, hopefully this weekend. Is it OK to just let those wires hang? Do I even need to tape up the cut ends? Measuring voltage for each stator leg to ground, should the bike be a running at 5000 RPM?

yes leg to ground ang leg to leg both at 5k are the only ones that matter.

[Rich82GS750TZ]

I'll get to testing the voltage in the stator legs to ground. In the mean time, I got the SH775 and wanted to check how it would fit. As shown in the top pic, it's really tight and I doubt the + & - connections would clear the frame if I tried To mount it roughly in that location. Then I remembered I have a tool kit frame that mounts over all of this. I don't have the kit, so I removed it years ago and tossed it in a box of miscellaneous GS parts. The RR fits almost perfectly as shown in the bottom pic. Just need to drill some holes and mount it with bolts. Full access with no binding for the plugs below. I haven't checked the fit of the side panel to see if that clears. Could I be this lucky? Is there any reason I shouldn't mount the RR here? Besides the fact that it covers the fuse box access cutout, I can't think of a reason not to do this.
IMG_3677.jpg

[posplayr]

Anyplace on the side plat would be fine. Other members have mounted to the backside of the same plate if you have clearance.

[Rich82GS750TZ]

OK. I've tested
Stator
Leg to Leg 89,90,89 VAC
Leg to ground 44,43,44 VAC
Numbers flucuated around a bit. Son was holding the RPMs around 5K.

So does this further the case that the stator is good, or does it need to be replaced?

[GSXR7ED]

This is an interesting topic. I have the R/R upgrade but have not installed it. What's up with the headlight loop thing?


Ed

[posplayr]

OK. I've tested
Stator
Leg to Leg 89,90,89 VAC
Leg to ground 44,43,44 VAC
Numbers flucuated around a bit. Son was holding the RPS around 5K.

So does this further the case that the stator is good, or does it need to be replaces?

Stator VERY BAD.

The stator is supposed to be isolated from everything except the R/R at the 3 yellow wires.

This is a very clear example of the difficulty of fault isolating the stator. If you had done the ohm meter tests your would have surely passed with flying colors. You passed the leg to leg with fly colors, but alas there is some leakage going on so your insulation is breaking down and you are picking up the voltage from the stator on your engine ground.

This explains why you are getting no voltage increase on the 12V battery. (Steps #4 and #5 below 14V)

When you pull the stator it will probably be fried in which case you should also change the R/R because it is in all likelihood it is a SHUNT R/R and it is what is ruining the stator.

[posplayr]

This is an interesting topic. I have the R/R upgrade but have not installed it. What's up with the headlight loop thing?


Ed

Follow directions for R/R installation: Do not pass Go, Go directly to "Wire stator (3 wires) direct to the R/R"

[Rich82GS750TZ]

Dang it. I've got my new SH775 RR ready to go. I'll have to replace the stator first and run these tests again.

OK then, What stator to get and who to buy it from? Rick's or Electrosport. I've shopped them a bit from going from links on this forum (that's the only reason I know the names Rick's and Electrosport).

Electrosport has one for GS750E/GSX750 (16-valve)(80-83)
My bike is a '82 GS750TZ. Same stator? $119.00

Ricks has one for that lists my bike for $144.95.

https://ricksmotorsportelectrics.com/New-OEM-Style-Suzuki-Stator-21_302

I think I read a post somewhere here that I can put a 2x4 under the left side of the bike center stand so it tips the bike enough to remove the stator cover without first draining the oil. Did I dream this or is this possible?

[posplayr]

The Electrosport is supposed to boost output by what they claim is 20%, but this would only occur at less than 2500 RPM and above that the rotor limits current.

Someone else posted that they now provide a preplacement bubber block grommet/gland.

Given the price difference, the ES would be the way to go.

Yes just tilt the bike and there will be a minimum of drainage.