77 B1 Stator rotor issues?

Hi this is my first post on here.
I'm so frustrated. My B1 just won't charge.
I've diagnosed it as far as the rotor.
Do these ever fail? I don't see how they can go wrong?
The stator has been checked by a professional and was told its refurbished and practically brand new!
It chucks out exactly zero AC. I'd have thought the rotor even if completely shagged would still put out something.
Has anyone had or heard of similar problems?
I don't want to buy a rotor for no reason.
Oh are they meant to be magnetic? As my rotor isn't even slightly magnetic. Or do they become magnetic when they spin?
Im really new to motorcycle electrics as you may be able to tell.

Thanks in advance

Alex

I assume you have a 1977 Kawasaki Kz650B1.
If so, then does your alternator cover have three screws in a triangle pattern on the face? That confirms it is a 1977 charging system. Later years did not have that.

That uses a type of charging system called an excited field. The factory repair manual describes how to check it. No the rotor is not magnetic. It is a field inverter and simply re-directs magnetic field into the stator. You have a field coil which creates the magnetism when the regulator provides power to it.

The manual describes how to bypass the regulator to put full power on the field coil (not recommended for long periods). This will test the stator output (when the bike is running).

I strongly suggest getting a manual before going much further into the bike. That is the fastest way to get most information about the bike including electrics.

loudhvx gave great advice. Use the Kawasaki Service Manual to troubleshoot the problem. If you do not have the manual say so and we'll provide a link. Also, make sure your bike is a 1977 KZ650-B1. If the generator cover looks like the one pictured below (notice I have circled the 3 allen bolts) it is; if it looks different it is not. I've owned my 1977 KZ650-C1 since it was new and the generator has never caused any problems at all; they are well built. Ed

Thanks for the replies. No I don't have service manual.
I'm baffled now. I had hoped it was the rotor.
I've done every other check.
Yes it's a B1.

You should try to find a Kawasaki Service (Shop) Manual, sometimes they show up on eBay. Be SURE to get one for your bike's exact year and model as there are significant differences between the years and models. In the mean time there is an electronic copy at the link below. Take some time and look through the charging system troubleshooting section starting on page 192. If you run those tests you should be able to pinpoint the problem. Ed

www.kzrider.com/modules/ServiceManuals/K...Service%20Manual.pdf

Having an issue keeping even a new battery charged. I can run for about 20 miles and then my 77 B1 stumbles, loses power then dead sticks to a halt. Will be digging into this winter. Any thoughts here? I have an owners manual and service manual.... wI'll be checking out.

The manual describes the system pretty thoroughly. There are a few tests and adjustments to do.
I think the most likely component to fail is probably the rectifier. They are easy to get.
There is a definitive test for the regulator described in the manual. If it turns out to be the regulator, www.oregonmotorcycleparts.com has the correct one for the 77 Kz650. They will have a rectifier too, but it's a little pricey.