Need Help With Rectifier Wiring

I am rebuilding 1980 KZ550 and replacing the rectifier. The new one has a different connector than the old one and the new rectifier has 3 white wires and one black in the connection block and the single red wire. The old rectifier had 2 yellow, 1 brown, and 1 black wire in the connection block and a single yellow/red wire. I will swap the connection blocks but how do I figure out which of the 3 white wires should connect to the brown?
Thanks Tomas

Take a good look at the old unit and make sure the wires are not really faded yellow, blue, and pink or 3 yellow wires. If any of the above they will connect to the 3 whites on the new unit. The other two will go to ground and power.

Where did you get the new unit? I believe it is the wrong one for your bike. Take a look at the 1980 KZ550-A1 wiring diagram below. There is no way a correct regulator/rectifier should have 3 wires that are all the same color, but your new unit has 3 white wires. Do yourself a big favor and before you take a chance on blowing your alternator or frying your electrical system call the folks at Oregon and ask which unit your bike should use. Here's their link. Ed

www.oregonmotorcycleparts.com/Products.html

Here's a link to a larger version of the diagram below:
home.comcast.net/~loudgpz/GPZweb/Mnls/Kz...kawKz550A1_UsCan.jpg

Thanks I ordered my replacement rectifier from Z1 enterprises and it was listed as being for the KZ550. I checked Oregon's web site and the only rectifier they show looks just like the one I have with 3 white wires, 1 black and 1 red. I will phone them tomorrow.
Thanks
Tomas

Almost all KZ550's were 3-phase with the little-known exception being the first year, 1980 models which were 1-phase (two-yellow wires).

Even some 1980 550's may have been 3-phase, since Kawasaki was in the process of changing everything over to 3-phase around that time.

Often, a 3-phase reg/rec will have the same spec parts as a 1-phase, in which case you can just use the 3-phase unit and leave the extra phase unconnected. But if you can get the right 1-phase unit, that's the way to go. If no one has one for the 550, you can use one of the combo reg/regs for the 1978/1979 KZ650's. Those were 1-phase, but did not have the brown wire. In this case, you would leave the brown wire from the harness unconnected (and taped up).

Also that separate, extra lead is white and red striped, not yellow/red. It may look yellow from age, but was originally white. It is the positive output wire.

Thanks Lou I really appreciate the help. The new rectifier that I ordered from Z1 originally came from Rick's Motorsports Electrics so I phoned them but Rick wasn't in. Marie said the rectifier I got was a 3 phase and wanted a picture of my old rectifier and that Rick would get back to me. After reading your response I did some reading on single versus three phase which helped but my electrical knowledge and understanding is not very good. I will see if Rick's can get the right rectifier for me and if they can't I will try your solution of the 78/79 KZ650.
Thanks again Tomas