1977 gs750 not charging

[garyS-NJ]

My 1977 gs750 is not charging the battery.. (it was, but not now, and the battery is good) I found browned insulation at thd bullet connectors between the stator and rectifier which tells me something went south. Each stator leg to another reads 1.5 ohms and all three are open to ground so it seems good. (I couldn't find specs for stator resistance does snyone know?) The rectifier reads .4 ohms ground to yellow and and .4 ohms yellow to red so I think that's good. I'm thinking the regulator (mounted under the battery box? Went south but idk how to test that. Googling and partzilla indicates my system does have the separate regulator snd it's a crappy design just shunting one leg of the stator somehow idk. Again googling seems to indicate the standard repair/upgrade is to use s Honda cb400 rectifier/regulator but I see the gs850 has s combination rectifier/regulator eould I be better to use that?

 

[Nessism]

There are literally thousands of posts here about fixing charging systems. Short answer: get a combo R/R SH775 and new stator. Wire like shown..,

SH775 Install by nessism, on Flickr

 

[tom203]

Heed Nessism’s short answer. Measuring ohms is inconclusive, cuz when installed in running bike , the stator is tugged and tortured by the spinning magnet field.
note that your bike probably has the older 12 pole stator , so make sure you get similar.

 

[salty_monk]

You can do an AC test on the stator. Usually if that's the problem you'll see that one of the legs is dead. A lot of times you only need the new RR...

 

[garyS-NJ]

Sorry again late reply it was the stock regulator mounted under the battery box so I swapped in a combined R/R from a 1980 CB400.

 

[uk gs nut]

Find a rotor and matching stator from a later gs550, 18 pole instead of 12.

 

[unfocused]

Make sure all your grounds are good, clean and tight. I still have my completely stock charging system on my 77 750 with no issues. But I've added/replaced most ground cables with stereo power cables. Don't go cheap or buy some wonderful walking shoes...!

 

[Suzukian]

The grounds on these bikes or really bad. A lot of Suzuki batteries ground to the engine, and they ground onto a painted surface, relying on the threads to provide ground. This causes the bolt to ground, and then your bike has a floating ground, which causes many many problems. Do what Nessism​ suggests, and make sure your grounds are good. If it is going to the engine, file that spot to bare aluminum to get a good ground. Check all grounds.