GS 850 Charging

[Guest]

Hi all.

l have replaced the stator. Rectifier/Regulator and the battety with new units and it is still not charging fully. Ar 3000rpm it onvy reaches 12.7v and with lights on drops to 12.3v. At a steady 4000rpm with no lights it will creap up to 13v. Can you offer any advice. It is a 1979 GS850. When I switch off the ignition the battery reads 12.4v

Chris.

[robertbarr]

The 1979 850 originally used a 12-pole stator, and of course a matching rotor. Unless you specifically sought a 12-pole stator, that's at least one problem. A stator for an 80 or later won't do it.

[posplayr]

do all the steps in the Quick test and report.

[bwringer]

The 1979 850 originally used a 12-pole stator, and of course a matching rotor. Unless you specifically sought a 12-pole stator, that's at least one problem. A stator for an 80 or later won't do it.

I also suspect this is your issue -- there are no new 12 pole stators available, and you didn't mention having yours re-wound.

The simplest solution is probably to install a rotor from a 1980-83 GS850. Then you'll enjoy an upgraded electrical system.

Post a "part wanted" ad in the proper section of the forum, and you'll probably find one cheap pretty easily. Pulling the old one can be a pain in the rear, though.

[Chris Finlay]

Thanks. How many segments should be in the rotor for the different stators.

[Steve]

Stick a screwdriver or nail in the rotor, slide it around, counting how many times it grabs on a magnetic pole.

A stock 12-pole rotor will grab 4 times. If it has been upgraded to a newer 18-pole system, it will grab 6 times.

I have some 12-pole stators that should be arriving any day, if you are interested.

.

[Chris Finlay]

Thanks. Looks like I have the wrong rotor for the stator. I have a spare engine with the correct rotor so I can swop it over. I will let you know how it works.

[Steve]

Numbers have never been given in this thread, so please verify:

How many "grabs" on the rotor?

How many poles on the replacement stator?

.

[JTGS850GL]

Numbers have never been given in this thread, so please verify:

How many "grabs" on the rotor?

How many poles on the replacement stator?

.

Steve, you may be incorrect on the "number of grabs". I just verified on one of my spare GS1000 engines and it "grabbed" 12 times on a 12 pole rotor per 360 degrees. Makes sense since the stator needs to have a pole transition for each of the stator pole windings as it rotates. Each pole of the stator needs to cross with a magnetic field at the same time as it rotates through. It's why a 12 pole stator doesn't work in an 18 pole rotor and visa versa.

Edit:
Now there are actually 3 segments per rotor so each segment would have the number of grabs you quoted. On a 12 pole rotor you would have 3 segments x 4 poles (grabs) per segment = 12 poles (grabs) total as you go around one revolution of the rotor.

Just wanted to clarify what should be expected when checking how many poles on a stator are needed for a given rotor.

[Steve]

You could be right (about me beeing wrong ). I will have to check a spare rotor that I have.

I just seem to remember that the number of "grabs" was 1/3 of the number of poles on the stator.

.

[Chris Finlay]

Hi all. Managed to remove one rotor with a 2 leged pullers bur the other one refuses to budge. I have soaked it in wd40. I will try again tomorrow.

[mrbill5491]

Hi all. Managed to remove one rotor with a 2 leged pullers bur the other one refuses to budge. I have soaked it in wd40. I will try again tomorrow.

Soak it with PB parts blaster, liquid wrench or the like yer just wd40ing in the wind with that stuff.

[JTGS850GL]

WD never really did it for me either. PB Blaster works pretty good. Especially when combined with heat.

[mikerophone]

+1 on the heat but for me 50% acetone / 50% ATF works a treat and is cheap. I refilled a pump spray bottle I had lying around - shake it up, spray it on and let it do the work.

WD is great for Displacing Water and not much else. I have 2 cans of PB Blaster that I don't intend to replace when they run out. The acetone/ATF mix is my new go to.

Edit: autocorrect!

[Chris Finlay]

Tried a hydraulic pullers on it tonight without success.