Magnetic field?

[gsrick]

(Sorry in advance, I'm posting from my flip phone and can't separate the text. I'll use multiple posts to get the story out, so please wait till I'm done before responding.) Ok here is the question/problem. '79 750L charging went kaput. Tested stator for continuity and insulation break down.(passed) Tested R/R and found a bad diode. Replaced it with a new R/R- new R/R passed diode test, but failed to put out proper charging voltage (4.5v). Replaced it with a known good R/R(off my 1000G). Result was 12.5v at red lead, not great but battery voltage, so I figured it was doing its job of regulating and the battery had enough charge. So off went the bike. (continued next post)

[gsrick]

(continued) A few days later I get a call saying the battery is still dieing. So I test the stator again only I also check AC votage output unloaded and get 14-15 volts max. I should get around 75v @ 5k rpm, so the stator must be bad. Order new one and in the mean time the company that sent the new R/R wont accept a return/replacement until it is tested with a new stator. Ok by me we have one ordered. New stator arrives and I do the pre tests before instalation and all seems good. Install it with my R/R and I'm getting battery votage at the bat. No more no less. I test R/R output, 4.5v. ?¿?. Tested my R/R and its toast. Hook up the origional replacement R/R and only get 4.5v. arrrrgh. test new stator unloaded stator and only get 14.5v max again. A bad new stator? Not unheard of, so back it goes. Last night the replacement new stator arrives and nothing changed. 14.5 v AC max from the stator. It doesn't seem to compute. My '78 1000 and '81 550T(brand new stator) both put out 75+ VAC @ 5k, with the same lead to lead unloaded stator test. So the question now is, can the rotor loose its magnetic field? That is the only other variable left in the charging system. I have a bad engine I can get a rotor off of, but I've never heard of this happening. What say you? Thanks in advance.

[Steve]

How many poles on the new stator?

You should have 12. It might have come with 18, which is standard for newer GSes.

They are NOT interchangeable.

.

[gsrick]

I'm not at home to be sure, but if memory serves me right, it has 12 and the only difference I noted between the origonal and the new stator, was the anount of coating on the windings.

[gsrick]

I done a little interweb searching and it seems possible for the rotors magnets to lose their strength. I was relaying to the owner what is going on with his bike, when it dawned on me that each time I pulled off and replaced the stator cover, that is seemed easy. The rotor didn't tug on the stator like they normaly do. they'll pinch the tips of your fingers off if your not careful or quick enough. Guess I'll try a different rotor from a bench motor tonight after school.