PMA Problem

[mike_d]

Hi Guys,

I just picked up a '76 XS650. PO informed me that he was having battery charging issues. I pulled the cover today and had a look. He had a mikesxs pma system installed and it was not charging the battery at any RPM (12.4 at all rpms...). The mounting plate was broken and only held on by one screw though everything else looked OK. It appears that the PO installed the plate improperly and was unable to get it flush with the crank-case. Would this affect the stator output? Is it possible that the stator is finished? Obviously I need a new plate, but I'd like to avoid dropping $300 on a whole new kit.

Also, the bike was running a little rugged when I purchased. I pulled the vm-34 carbs and saw that the floats were sticking -- cleaned it all up and seemed to idle fine (though, didn't want to ride with no charge). Inside was a P6 needle jet, 25 pilot and a 160 main. Does this seem about right? Stock exhaust, k&n filter....

Lastly, has anyone made the side covers work with the vm-34's? PO had them off but I like the way they look. Any suggestions or pics?

Thanks!

 

[XSLeo]

Lets start by welcoming you to the site. Welcome to the site.
Now onto your question. If the backing plate won't seat right it could cock the stator enough so it rubs on the rotor. This can damage the stator. Enough so it won't work? Can't say, I can't see it.
I would replace the broken plate. If it fits too tight you can file a bit away on the outside edge so it fits. It fits inside three projections on the case. To fit file a tiny bit where it touches these spots. Too much from one place may get it off center.
On the stator do the ohms check with your meter. Number the three wires 1, 2, 3. Now test the ohms from 1-2, 2-3, 1-3. They should all be the same. Also check from the wires to the steel body. You don't want continuity this way.
If these ohms check ok, then check the wiring to the reg/rec. Check grounds.
Now start the bike and using your meter on the AC scale, check the output of the three wires from the stator. Check the wires 1-2, 2-3,1-3 same as with the ohms test. All three legs should put out the same AC voltage. If you get voltage then the reg/rec is the problem.
This should keep you busy for a bit. So do these things and report back what you find.
Leo

 

[mike_d]

Hi XSLeo!

Can't thank you enough for responding. And I didn't mean to let this thread sit here -- I reckon that is quite a problem on the site. Better to follow up as to help others.

SO! I forgot to mention when I posted this that I needed the bike running ASAP as it was going to be used for a photo shoot that needed to be ridden to. Since I was getting PAID for this I needed it running NOW so I just ordered a new backing plate, stator and rectifier. Turns out it was the rectifier. The old stator was fine. I got the new backing plate in there and installed properly. So I got a mikesxs pma stator laying around should someone need one.

I now have the bike running great though I do have some other smaller questions that I will create a separate thread for. Thanks again XSLeo.