77 rectifier is shot .... recomendations?

Figures. I found my rectifier with a terminal busted off. I have a million spare parts but no 77 rectifier. Seen new OEM one for $270+ and a bunch that do not look like mine but claim to be for a 77b1 for about $80. Then I hear you can build one. Suggestions? Been there..done that? Encouragement? Screwed? Na never screwed with a KZ?

I also see Z1 has one for $104. Looks like too many wires tho. Anyone use one?

Some information(I believe it should work for your application):

Ninja 500 voltage regulator on a KZ650


1981 KZ650-CSR w 3-phase alternator (3 yellow wires) & a 6-wire regulator-rectifier w the brown sensor wire.

Some of you probably already know this stuff, and it's kind of intended for the novice such as myself.
If your R/R is shot, you might be able to use one from a more modern motorcycle. I installed one from a low mileage 2007 Ninja 500 (EX500)($20 on eebbaayy)(credit to Loudhvx). The wiring is the same, so it was very straight forward. Plug & play would've been nice, but the connector wouldn't mate to the wire harness connector as they both had female terminals. So I had to do a little electrical work which was no big deal, but you need the proper tools to do the job. The bike has open barrel terminals, so I got the same type & a replacement connector at CycleTerminal.com. VintageConnections is another place. Z1Enterprises.com probably has the stuff as well.

An open barrel crimper is needed to properly crimp the terminals. I already had a HF ratcheting crimper, but the crimper die set was incorrect for the job, so I got replacement dies on Amazon.com - they were almost a perfect fit. A terminal extractor/removal tool is also handy to have. I got a set from the same place as the terminals & connector - they seem to be high quality & look kinda like little screwdrivers & make the job very easy without damaging anything.

I was originally going to buy a new R/R from somewhere, but thanks to loudhvx the route I took ended up working out pretty good. For about the same amount of money, I now have the tools and a selection of terminals & connectors for doing future repairs, plus I have a fairly new voltage regulator. And I now know how easy electrical work can be if you have the proper tools & a little practice.


Re: Ninja 500 voltage regulator on a KZ650
Wired George wrote:
On the oldest rectifiers, there will usually be one extra wire when you go to rewire... The separate rectifiers will have a "sense" wire that connects into one of the bike's electrical circuits and the voltage on this wire tells the rectifier how much voltage it needs to make... Newer combo reg/rec units like the one you bought do NOT have this type wire as it will use the feedback from the WHITE wire which is the wire that supplies to the main fuse to do the voltage adjustment so if you are spicing in a newer combo reg/rec, this is something you will need to know as you won't figure out why the extra wire after matching up all the others. The circuit is generally a brown wire that provides voltage feedback on a Kaw. All the aftermarket reg/rec units will only have 5 wires for this reason.

Re: Ninja 500 voltage regulator on a KZ650
Martin-CSR Wrote:
Thanks. Actually, the Ninja 500 R/R does have the brown sensor wire & it is virtually identical to the stock R/R on my 81 KZ650. The size, shape, wiring, & bolt hole spacing are the same. They have different, but similar, numbers stamped on them. You can actually use the numbers to figure out approximately how old one of them is, as the numbers get larger year on year. The 2007 part was the last year the EX500 had a pigtail connector. The Vulcan 500s had the pigtail up until 2009, but I couldn't find one of those for less than $40 at the time. $20 was cheap & the Ninja only had 4k miles. And the part was a lot newer than my old one.
Re: Ninja 500 voltage regulator on a KZ650
Wired George Wrote
I wouldn't be concerned with the connector... I would just as soon solder all those connections anyway.... good point. I bought an aftermarket replacement for one of my test bikes and it didn't have the sense number. The R&R tends to fail as they get warm and are usually tucked out of the airflow on many bikes. I never considered buying a late model Kaw used part but certainly will the next time as the aftermarket part was pricey. I HATE dealing with old junk electrical stuff.

Re: Ninja 500 voltage regulator on a KZ650
Martin-CSR Wrote:
Supposedly, reg-rec failure is a problem on Ninja 500s, so I guess there is some risk, even when buying one the way I did (ie, fairly new & low mileage & good visual condition, kinda like new). But I think the so-called problem is simply a melted connector, and that is probably just a poor or dirty connection.

Having the pigtail made for a good fit in this case, as the part was virtually identical to stock. According to the cross-reference at Kawasaki.com, a number of models have the same voltage regulator as my 81 650-CSR, including the 79 KZ1000-A3, so the Ninja part should work on those bikes & probably others. The one for the KZ750-F1 Ltd-Shaft is listed as an Active part & it is the same as the EX500. I'm pretty sure all of the Kawasaki reg-recs are made by the same Japanese company (Shindengen). Probably any differences are the wire colors &/or maybe the bolt-hole spacing, some are 5-wire or 6-wire, and some of them don't have the wiring pigtail.

The stock Kawasaki wire terminals are the open barrel type & are crimped w no soldering. I think if the proper crimper is used & the crimp is done correctly, the connection will be good & solid, and physically strong - ie, difficult to pull apart.



Re: Ninja 500 voltage regulator on a KZ650
Wired George Wrote:
You can also buy connector at Z1Enterprises and other places and attach wires to pins and then insert pins. I have the crimper shown in your bottom pic and it works very nicely on most single pin connectors.


Re: Ninja 500 voltage regulator on a KZ650
Martin-CSR Wrote:
What you described is the way the stock connectors are & that is what I did: crimped on new terminal pins, then inserted them into a new connector. When buying terminal pins for use in a connector, you have to be sure to get the type w the little locking tab (some don't have it). The HF crimper dies are incorrect for open barrel terminals, but you can get a die set from Amazon.com or elsewhere. Now that I know better, I'll never do a mash connection again. The open barrel crimper will curl the terminal ends so that they grip the wire & insulation firmly, giving a very good connection... no soldering necessary.

Aircraft Tool Supply Terminal Crimper Die Set (Open Barrel)

Klein Tools VDV205-036 Die Set for VDV200010 Non Insulated or Open Barrel Terminals 1020 AWG

All good info there, but unfortunately all of the above applies to permanent magnet systems, the 77 KZ 650s use an excited field system which is completely different.

Proxy, your best bet is Oregon Motorcycle Parts operated by Tony Weeks, he makes high quality electric replacements for older motorcycles and for very reasonable prices too.

I think what you need is his R255a rectifier (scroll down to the middle of the page in the link above) but probably best to check with Tony before you order, from what I've heard he's real helpful and easy to deal with - if I recall correctly Ed has one of his units on his 650 and can tell you more.

No eBay APP ID and/or Cert ID defined in Kunena configurationAs OnkelB mentoned, Mfolks info is good for later 650's but not the 1977. Luckily, the rectifier, by itself, is a very simple device on the 1977.

In addition to the Oregon and Z1E options, you can build one for about $10 or $15.
home.comcast.net/~loudgpz/GPZweb/RegRec/...3phaseRectifier.html
My buddy is still using the one I built for him 14 years ago.
You have to make a heatsink, basically just a plate of aluminum, but you have to find a place to fit it onto the bike.

It would be much easier, and maybe cheaper ($3) to get one already made on ebay from China.

Some guys were using these on their KZ400's, which use almost the same charging system as the 77 KZ650.

Basically, any 3-phase bridge rectifier rated for 25 to 100 amps, and 50 to 100 volts will work. Higher amps or volts is fine as well. But make sure they are weather proof (most are).

Search for OldKawMan. I think he will have a new one (aftermarket solid state unit) either way you should upgrade if you are still running regulator/rectifier. Unless you are staying all original equipment. He might have an OEM also. Also contact Baltimore Cycle Salvage. (Google it) don't have the number on me sorry. Good luck.