Charging system 1979 GS550

[bill_face]

Hello all.

I am trying to revive a 1979 GS550, and have made a few posts here as I work my way through the problems.

I'm onto the charging system, and have found the stator pages and am attempting to follow it through, but I'm not entirely sure what I've got.

The charging system is charging a bit but not as much as it should. I measured a voltage of 12.6V at idle, this increases a bit if you rev it, but not much.

I've taken a few photos. I think I have an 18 core generator and matching rotor (which I gather were from later bikes). I think I might have a separate r/r but am not sure.

There are three cables that come up from the generator (blue/white, green/white and yellow). There are 5 cables connected to the rectifier (blue/white and yellow from the generator, red and black, and a red/white cable that i presume has been spliced into the green/white from the generator).

So firstly I would like confirmation of what parts I have if possible?

https://imgur.com/5dUE5Ip
https://imgur.com/ShdKsKh
https://imgur.com/1ialTb7
https://imgur.com/78OTHq4
https://imgur.com/FeFN6uS

 

[Guest]

A 79 550 would have a seperate rectifier and regulator. I forget exactly where they were located, but the factory manual will tell you. Have you found the copy on Basscliff's site?

 

[tom203]

Your pic shows a 18 pole stator ..hopefully it has the matching revolving rotor to go with it.. Your rotor should have 6 pairs of N/S magnets. Someone might have changed the stator out but left the older rotor with 4 pairs of N/S magnets - this will have poor output even it looks better than this stator

 

[hannibal]

Follow the yellow wire from the stator. It should split with one end going to the regulator(left side of the bike) and the other going to the rectifier (right side of the bike).

The W/G wire from the stator runs to the headlight switch and returns as a W/R wire into the rectifier. You'll want to eliminate this headlight loop and send the W/G from the stator directly to the new R/R.

Have you read about using a SH775 to replace your factory regulator and rectifier? You should!

 

[bill_face]

I have read about the SH775, but I've spent a lot of money on this bike so far, and now need to work with what I've got for a while. There are links to the pics in the original post but I'll attach a pic of the rotor.

 

[Steve]

I have read about the SH775, but I've spent a lot of money on this bike so far, and now need to work with what I've got for a while. There are links to the pics in the original post but I'll attach a pic of the rotor.

Do you really LIKE spending money on the bike? :-k If not, get the SH775 and install it now, otherwise, you will be getting it later, along with a new stator and gasket and all the hassle of getting that wire bundle through the starter cavity. Probably have to remove the carbs to do that. How much of that is already removed right now?

Yes, that is an 18-pole stator, It's rather hard to tell what rotor you have just by looking at it. Use a screwdriver or some other metal object, run it around the inside edge. You should feel it pull 12 times. If it does, at least the rotor and stator match.

You say you have a '79 550. It might actually be an '80. Two ways to check, one is real quick and easy, the other is only slightly harder.
1. Is there a kick starter?
2. What is the production date on the VIN plate?
If you don't have a kick start lever, you have an '80. Why might you think you have a '79? Because production of the '80 models started about August or September of '79, leading many to think they have a '79 bike. The assembly date on the VIN plate would be your definitive answer.

.

 

[bill_face]

Steve you make a very convincing argument.

So in the UK, I have a couple of options on the SH775. Either from italy for ?90, or from China for ?18. I'm thinking there may be a US version as well.

Could someone clarify? I'll post ebay links to what is easily available here.

P.S My rotor has 12 magnets, I just checked with an allen key. And the bike is a '79. Hsven't found the Vin Plate, as I think it may be under several layers of paint, but it has a kick start. So someone has changed the rotor and generator.

https://www.ebay.co.uk/i/2322313521...7&rk=2&rkt=4&sd=322415306368&itm=232231352112

https://www.ebay.co.uk/itm/Black-Vo...m=392086297174&_trksid=p2045573.c101006.m3226

 

[Rich82GS750TZ]

NOPE! I can't believe they're actually stamping SH775 on the top fin on these knock-off RRs. Somebody correct me if I'm wrong but this is a cheap shunt, not a legit series RR.

this ain't it either

 

[2BRacing]

…..So in the UK, I have a couple of options on the SH775. Either from italy for ?90, or from China for ?18. I'm thinking there may be a US version as well.

Could someone clarify? I'll post ebay links to what is easily available here.

https://www.ebay.co.uk/i/2322313521...7&rk=2&rkt=4&sd=322415306368&itm=232231352112

https://www.ebay.co.uk/itm/Black-Vo...m=392086297174&_trksid=p2045573.c101006.m3226

No, both those are not the genuine part. Look here for the correct one offered for sale by a member here: www.thegsresources.com/_forum/showthread.php?253829-Shindengen-SH775-R-R

 

[Guest]

Bill, It's not easy to find a genuine SH775 over here, but they do crop up from time to time. It's worth searching, as it's the best alternative available. But, for a stopgap, the old Honda R/Rs work OK, and are far more available. It might be worth looking for a SH-232, just to check your system out.

https://www.ebay.co.uk/itm/Honda-CX...h=item363df96ac1:g:1HsAAOSwi1pblAiz:rk:2:pf:0

And in the meantime, the best thing you can do is clean all the connections thoroughly, then check your charging system again. You'd be amazed how much effect 40 years of corrosion can have.

 

[bill_face]

One more question about the SH775. Is it going to enable to me to add a few accessories onto the bike? I would like to be able to charge a mobile phone (5W), run a sat nav (5W), and run some LED daytime running lights (10W) simultaneously. Ideally having the headlights on at the same time.

 

[standswithabeer]

"The charging system is charging a bit but not as much as it should. I measured a voltage of 12.6V at idle, this increases a bit if you rev it, but not much."

i've refreshed quite a few bikes, usually early seventies honda cb750's, a cb550 and a cb350f, and a few earlier one ones too, along with a smattering of 2-strokes. polishing both ends of the both battery leads, followed by each connection in the entire harness is a two-beer job, but is really necessary when bringing an old bike back to life. oxidized connections, or connections via corroded fasteners to a painted frame will result in poor performance overall. weak spark, dim lights, poor charging system measurements, etc.

so i'll have to ask, have you cleaned the battery leads and R/R connections? what are you voltage reading across the battery when rev'd? and good luck in your endeavors,
bob p

 

[bill_face]

No, I haven't cleaned all connections. I wasn't really sure what was what and what to clean. However I'm a lot clearer now, and cleaning all connections everywhere wouldn't do anything but help.

I'm in the process of buying SH775 off a forum member, so hopefully cleaning and installing that will sort it all out.

Is there any different advice about wiring the SH775 into a kick starter era GS with separate regulator and rectifier?

 

[Brendan W]

No, I haven't cleaned all connections. I wasn't really sure what was what and what to clean. However I'm a lot clearer now, and cleaning all connections everywhere wouldn't do anything but help.

I'm in the process of buying SH775 off a forum member, so hopefully cleaning and installing that will sort it all out.

Is there any different advice about wiring the SH775 into a kick starter era GS with separate regulator and rectifier?

Not really. The essential idea is that all three stator phases go direct to the R/R unit. The phase loop to the headlight is redundant.
Single Point Ground, SPG is a refinement you can consider. It lets the charging system have a better view of the battery amongst other things.
When you get time it's well worth opening and cleaning the ignition switch and the kill switch. After 40 odd years these can drop a volt or more from your coils making starting more difficult.
Other things worth cleaning, well everything but in particular the supply plugs for the coils and the plugs for the handlebar switches. All of these will generally be close together under the tank.