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I'm throwing a newer motor (not certain of the year - came with the bike} into my old '76 kz650. Alternator is 2 phase?? My old kawi is 3 phase? can these be married without too much modification...new regulator required?
Any help would be greatly appreciated! And thanks to the KZrider community for this forum!

It's not impossible, but it would be better if you used the rectifier/reg assembly designed to go with the alternator.

If you use an alt with only two AC leads into a rectifier designed for three AC input lines, it means the two sets of SCR's that are working will be pulling more current than in a 3 ph system. It might work (?)

Thanks for the reply - if I replace the rectifier and regulator to a 2 phase set-up, would that suffice? Or is there further issue with current involved regardless?? Thanks for you help!

I didn't know there was a 76 KZ650. Are you sure it's not a 77 KZ650 manufactured in 76?

The 77 uses a 3-phase, excited field alternator with seperate regulator and rectifier. The later ones up to about 1980 used 1-phase, permanent magnet alternators with a reg/rec combo. 1981 and later used 3-phase, permanent magnet alternators with reg/rec combo. The 77 regulator works on a totally different principle and is not compatible with the later alternators.

You would have to remove the seperate reg and rec and put in the combo reg/rec. This means some wiring will have to change in the harness. Other than that it should be no problem.

thanks loudhvx - the fog between me and the old KZ is lifting. I've had this one for 15 years or so and I took it apart several years ago after alot of miles. Needless to say I can't part with it and have limited knowledge in these things but always up for a challenge! To put on a combo reg/rec sounds reasonable.
In just two responses on this forum I have almost all the info I need - can't thank you guys enough!!