Motorcycle Repair: cb750k charging system, stator coil, regulator rectifier

Question
chris, I have a 79 cb750k, its not charging.I have tested the stator and the rectifier and they test good. How can I test the rotor and regulator? Thanks for any help you can give me                                                                             bill

Answer
Hi Bill.
 There are only 3 major components to the charging system.  They are the stator coil, regulator/rectifier, and battery.  Outside of that, the only thing in the charging system that can fail is the wiring.

 Have you checked the battery with a hygrometer and the wiring for shorts?

How did you test the stator?  Did you test it at the coil plug or at the battery terminals as the bike was running?  Testing at the coil you were measuring ACV and the regulator/rectifier converts it to DCV for charging the battery. What was the voltage that you got?  If you tested at the terminals, then you should have gotten 13 - 15 VDC at the terminals.  Anything less and you have a bad stator coil.

As far as testing the regulator/rectifier, each make/model is a bit different and so you need to reference the repair manual for testing proceedures and specs on that.

Check those out and let me know what you find.
Good luck.
FALCON