the voltage stays at 11.2 and veeery slowly drops untill its dead.

we tried the alternator, switched 3 different regulators and still nothing

cant figure out whats wrong with it.

 

Check the stator windings, they are notorious for going bad on old UJM bikes.

 

replaced that recently.

 

So you've got the regulator and stator covered, best I can recommend is double check your power and grounds. Do a voltage drop on each side and make sure there isn't some sneaky resistance choking off the alternator.

 

yea its increasing with RPM but not much.
just under 1 volt increase at 5000 rpm
we tried like 3-4 different regulators already.

 

As I recall, it should top out at like 14.5v at 3K rpm.

If you do a quick search at one of my favorite websites... http://forums.sohc4.net, you'll have a better answer.

Oh, I had a problem with my cb550's charging system, as well. The bullet connectors from the stator keep backing out. I solved it by cleaning the connector, and crimping it, then wrapped it with eletrical tape. Anyway, just an idea.

 

ok were back at it.
found a blown rectifier today( the small diode box with ttwo green/red wires...

weird thing is when i test the regulators( we have 4)

when i test green wire to any yellow normal polarity my craftsman voltmeter shows within specs. but would not show anything in reverse polarity.
then we got fluke meter that doesnt show anything in normal polarity and shows a bit over 2000 ohm in reverse polarity which is what the book says.

so i dont know wtf how can one meter show one thing and the other opposite.

the voltage will go up to 11.8-11.9 and stay there if we keep the bike at around 3000 rpm. if it idles the voltage starts dropping..



what is connected to those black and white wires that are in the stator. with 2 spring loaded contacts.

is that electromagnet?