[kirrbby]

A stock K3 (72) Z50 has no battery. There's only a headlight, with a on off switch...and a taillight, no brake light. Everything runs on AC.

 

[kirrbby]

12 VOLT REGULATOR RECTIFIER COMBINATION UNIT (214W) (S1070)

 

[kirrbby]

 

[kirrbby]

Yellow from regulator, T'd into frame harness red. Correct green grounded.
That should work..? Regulates the bikes ONLY hot lighting wire..?

 

[kirrbby]

It seems like that's how you had it wired initially tho.

On some of the lifans...the stator is grounded. On others, it's not grounded. When it's not, I think there is a green wire that can be used as a frame ground...attached to the frame OR the engine, on your bike.

 

[kirrbby]

In your pics...we can't see what wires come from where. Your original wiring only had 2 wires from the engine plug. Black for ignition. And a red wire for lighting.

Your new engine would need 2 for the ignition.
One for lighting.

And maybe you would need to connect one to a frame ground...4 wires max.

 

[kirrbby]

Couple thoughts...
You ONLY need a REGULATOR for your setup. I think what you have is a reg/rec... regulator AND rectifier combination unit. So you should only be using the regulator part of your reg/rec.

The other thing I'm thinking...
Our bikes use 2 different types of stators...half wave, OR full wave. Since your stator has the floating ground...I think you have the full wave. The reg/rec units ALSO come in half or full wave varieties...one or the other, and they don't interchange.

What I don't know, is if, when you grounded the pink wire, if you changed your FULL wave stator...or, "set it up", as a HALF wave..?
But I think it matters...half wave or full wave...both with, which reg/rec you have...and with how you have your bike wired.

So...the questions are...
Do you have a full wave system on your bike??
Do you have the correct reg/rec unit??
And, are you using the regulator side of your reg/rec??

 

[kirrbby]

Maybe full or half wave doesn't matter when you're not rectifying to DC..? I'm not sure about that now. It shouldn't matter for the regulator??

 

[kirrbby]

One other thing to check...the green wire, from the reg/rec, that you grounded...
Is it the one that is right below the yellow?? Or the one that is diagonal from the yellow?
It makes a difference which green you ground.

 

[kirrbby]

Your pictures keep us guessing. Every pic shows wires and connections, but I can't see where they come from or go to, etc...too close. We can zoom in to see detail, but we can't zoom out on a too close shot.

I'm 95% sure that your reg/rec is a half wave type. As Davmo said, if the one you have ain't workin, try the other type.
So you COULD buy a full wave type to try. I'm not convinced that is the problem...but it's a pretty good bet.
In your last pic, all I see is 3 red wires...or 2...spliced together...coming from and going to, somewhere..?

 

[kirrbby]

The last pic is the red from the factory harness tied in with the yellow from the rectifier and goes to the red on the headlight switch

How about the yellow from the stator?? That is supposed to be T'd into the wires you just described.