Faulty SH775?

[robertbarr]

There's an ebay seller named "powersportsnation" or something very similar, and they carry boatloads of R/R's, including the SH775's. I've purchased a few from them myself. In most cases, they'll provide a photo of the part number on the back end of the unit.

[blackhammer]

well, the charging issues have defeated my best efforts to resolve them.

I'm going to start another thread to more accurately detail my setup and what ive done to date to resolve it, in the hope i might get some other suggestions from more experienced heads.

[Chuck78]

FYI having a mismatched stator and rotor will cause zero charging system output also. You would have to have one or the other from a first-generation 77-79 GS, I believe they are 12 poles., whereas the newer ones are 18 poles. Divide that by three phases and that is how many magnets the rotor should have to correspond with the proper stator.

[blackhammer]

Thanks Chuck,
you know i havent counted the magnets on the rotor, mainly because i thought the only rotors that could fit the 1150 were the larger crank end ones, 83 up 1100 and 1150 only i think?
So i assumed there would be no way to fit a 12 pole rotor.. i will check it though.
On the basis of that presumption i got a new 18 pole stator.

[Chuck78]

I forgot which engine you were running, and was reminded about how absolutely potent that bike will be! Wow. 1150 engine in a twin shock frame, that is the ultimate GS... yes, not too likely that you could have a mix-up of an incompatible rotor, & it sounds like you definitely have an 18 pole stator.

Try running your starter motor and ignition off of a car battery to test it, but run it with the state or leads unhooked. Then test them on AC voltage to see what output they have. They should have somewhere in the neighborhood of 30 volts up to 50 or even maybe 80 volts at higher rpm's, I can't remember, I would have to refer to my notes.

Then you will want to check with the stator hooked up to the regulator rectifier, check the voltage coming out of the regulator rectifier. You should have around 13.5 or 14 volts. Then just follow it down stream with the wiring.


I would make absolutely for certain that you have the regulator rectifier grounded properly, I try to ground both the stainless steel base plate of the actual housing, and ground the far-right terminal if you are looking at it with the wiring connections at the bottom, and looking at the finned side. The innermost terminal position of the right connector, I believe is the positive output. Double check this and reference some other information to confirm my recollections, as you would have no output if you had the ground and positive output reversed, and very possibly could have just blown the sh775. And possibly blown the stator? Don't worry if something similar to this did in fact happen, we've all done similar things at one point in our lives... learning experiences gained...

I would unhook everything else downstream after the regulator rectifier battery connections until you have determined the source of the problem, even if one segment of wiring at a time. Make sure that you have a proper ground to the frame, as in a single point ground and then directly to the battery,

[blackhammer]

1150 with 2mm over bore, some mild head work and RS36s
i hope 115-120hp at the wheel, but will still have to wait for 600kms or so to see what it can do.

thanks for the suggestions, ive pretty much tried all of those things, i thought id found an issue with the main battery earth to the case not being cleaned up properly after i painted the cases, i hadnt removed all the primer properly from under that bolt on the case. But after a solid hit with a flappy disc still nothing.

The connectors for positive and negative are in the correct spots on the SH775, all of the connectors are crimped and soldered. The single point ground is clean and close to the r/r.

ive put a basic diagram of the wiring below, and really there isnt much to go wrong. All of the load circuits run off the motogadget. and although i dont show an earth to the fram from the battery negative terminal i have added it as part of testing. I havent tried running a separate earth from the frame to the case as i thought the engine mounts were sufficient, and resistance between the case and from is low.

I havent tried earthing the steel bottom of the SH775 as i wasnt aware that was necessary, i will try it as the r/r is rubber mounted in my set up and the only earth is via the plug connector.


The only thing that is a bit funny from my testing is when im testing AC voltage across legs straight out of the stator (r/r disconnected).
Using a pretty good work fluke i have, all 3 legs show about 15V AC at idle, as i rev up it gets up to about 30V @ 4k rpm then goes open circuit??... then at about 6k rpm it comes back at 60V and gets up to 70/75 when i rev hard. All 3 do this.. i must of run this test about 10 times each leg trying to figure out if the fluke leads were moving...but they weren't, it was consistent, no idea if it means anything other than im doing something dodgey while testing.

Anyway, like i said before, im almost entirely out of ideas, i cannot understand why i cant get anything out of the 3 r/r i've tried.

Honestly, i think it can only be an earthing issue or something with the stator... All suggestions are welcome!

Nate.


connectors for r/r are all done like this.


engine case earth for batt cleaned up in stock position, electrical grease added.



this is where im testing the stator from.

[Chuck78]

Sounds like I'd be trying a different stator...

3 different rr's & zero output on any, with rr properly grounded and polarity correct, there should be no other issues aside from the stator/rotor...

Isn't that a new stator????
Did you have the old one? Or did it need returned for a core charge?
I'd consult the manufacturer or the stator as e'll as try g to swap another stator from a different source.

I don't think you'd have any other possible parts that could've gotten mixed up with yours, but make sure you have 18 poles on the stator and 6 magnetic poles on the rotor. And make sure they are all aligned properly. Perhaps you got a different spec stator that is a different thickness or spacing, and is not aligned with the rotor properly? A mismatched number of poles I thought would give you zero stator output, but I've only read of this, never had hands on experience.
The older rotors

[blackhammer]

Yeh, new electrex 18 pole stator. The measurements match the one that came out of it:
It's a G02:
Outer Diameter: 102mm Inner diameter: 38mm Thickness through hole: 18mm

I might put the 1150 stator side cover back on to try, I'm currently using an 1100 one as I prefer the look of them and all my research at the time on here said they were completely interchangeable.

I wonder if it's possible the on mine for some reason the rotor doesn't sit fully over the stator?
It's almost impossible to check tho...

Anyway, thanks for the suggestions

[Chuck78]

Give it a try...swapping the 1150 cover back on.

I think there's something wrong with your stator or the wiring. Maybe it's pinched by the cover somewhere?
Have you done resistance tests to the stator? I think it should read between 1.8 and 3 ohms iirc, between any pairing of two leads, and infinite ohms (no connection/continuity) between each lead and ground.

[Chuck78]

The single point ground is clean and close to the r/r.

ive put a basic diagram of the wiring below, and really there isnt much to go wrong. All of the load circuits run off the motogadget. and although i dont show an earth to the fram from the battery negative terminal i have added it as part of testing. I havent tried running a separate earth from the frame to the case as i thought the engine mounts were sufficient, and resistance between the case and from is low.

I havent tried earthing the steel bottom of the SH775 as i wasnt aware that was necessary, i will try it as the r/r is rubber mounted in my set up and the only earth is via the plug connector.


The only thing that is a bit funny from my testing is when im testing AC voltage across legs straight out of the stator (r/r disconnected).
Using a pretty good work fluke i have, all 3 legs show about 15V AC at idle, as i rev up it gets up to about 30V @ 4k rpm then goes open circuit??... then at about 6k rpm it comes back at 60V and gets up to 70/75 when i rev hard. All 3 do this.. i must've run this test about 10 times each leg trying to figure out if the fluke leads were moving...but they weren't, it was consistent, no idea if it means anything other than im doing something dodgey while testing.





Honestly, i think it can only be an earthing issue or something with the stator...

Looking at your diagram in depth this time, you are missing a CRITICAL ground....
The single point ground is not directly connected to the battery negative
As far as conductivity goes, copper is the highest conductor of the common metals (brass, silver/tin solder etc also), aluminum is lesser but decent, steel is the lowest of all commonly used conductors or ground paths.... dirty greasy painted steel connections are far worse off even...

Check out the stator extensively, perhaps swap the stator covers
Then run the battery negative to the single point ground, and run another ground to the engine case from the SPG - 6 or 8g stranded copper wire, the ignition system needs a really good ground...

If nothing is wrong with the stator, I think that's the only fault I see in the wiring, and it should work then.
The stator readings you got are very bizarre though, so I'm thinking there is an issue there as well. Definitely dun battery neg to SPG regardless, and heavy gauge ground strap engine to SPG. These both are VERY critical.

Even if that makes the r/r work, find out why the r/r drops out a output at that certain rpm range. That is NOT RIGHT...

[bobgroger]

Well perhaps if you buy another brand new one if this one turns out to be defective, you can just return the defective one on the same receipt as the one that you have just purchased! Otherwise, I'm pretty certain they would give you a hard time about the return since it is many months or a year later after the purchase of the faulty one... worth a try. Make sure it's faulty, first, though!

How in any way would that be ethical?

[roeme]

(...)The only thing that is a bit funny from my testing is when im testing AC voltage across legs straight out of the stator (r/r disconnected).
Using a pretty good work fluke i have, all 3 legs show about 15V AC at idle, as i rev up it gets up to about 30V @ 4k rpm then goes open circuit??... then at about 6k rpm it comes back at 60V and gets up to 70/75 when i rev hard.(...)

Fried stator or mismatched parts, or something else under that cover is amiss:

Sounds like the generator can't support any load. I'm willing to bet that these voltages will collapse as soon as power is required.

Confirm (or disprove) my hypothesis by measuring AC voltage under load. You'd also measure current to exclude a problem further "downstream", but since you've already used three different R/R's this should be already covered with reasonable confidence.

[Chuck78]

How in any way would that be ethical?

Because if he bought it from the same place, and it was defective... very simple, Bob. Bypassing the red tape to get his $ back on a defective part as is deserved. IF the stator is in fact bad.
Not all "rules" are for the good of us.
I'm fairly certain they have some sort of warranty, however. It IS a brand new stator...

[blackhammer]

Pulled the stator cover today to check magnets on the rotor vs stator poles.

4 magnet rotor and my new 18 pole stator.

so I guess that was the issue. Should have 12 pole stator.
but my understanding is there should be no AC out of the stator with current setup. Yet I'm still getting AC out.