TOPIC:

HI all. New to the site. Didn't realize how many KZ fans there were. Well I am also new to riding and bought a 1982 KZ550 LTD last november. I originally thought the stator was bad but just replaced that. Unfortunately it didn't fix the battery charging problem. So now I want to replace the regulator. Probably should have went with that first. Oh well, stupid me. The part I pulled of my bike is the part number SH230-12. I want to know if that is the correct part number for the model or if someone could send me a link to the correct part online that would be great. And also if anyone had any ideas on anything else if the regulator didn't fix it. Thanks y'all.

Post edited by: arswagger, at: 2007/03/02 12:51

arswagger wrote:

HI all. New to the site. Didn't realize how many KZ fans there were....

Hi arswagger and welcome to the forum
Look around on the top of the page you are reading now.
See those tabs along the top, mine are green, one says KZ information, right click on it, then select open in new window. When it opens, at top of new page, select filebase and click it then scroll down near bottom of the page and look for not model specific and click it. Then select document search and type in ELECTRICAL fault_finding.
The filebase has a lot of really good articles for you to check out at your leisure.

Is there a way to test the regulator to make sure its bad, like reading it out with a multimeter?

arswagger wrote:

Is there a way to test the regulator to make sure its bad, like reading it out with a multimeter?

Absolutely; but I have never had mine apart nor have I checked the voltage at the different terminals, so I can't help. I have a little electrical experience and do OK with general info/help, but nothing that is model specific nor even component specific.
A lot of these guys know the start/charge circuits by heart. They will be on-line when they get off-work.
Look for replys soon. You can PM me and maybe I will do some voltage checks and possibly learn something myself. I may not have time to check anything tonight, as I work the planetarium and observatory on Thursdays and Fridays. BTW, goto chit chat; I am going to post something there of a astronomical nature that takes place tomorrow and it is __WAY KOOL__ !!

Does it have a test procedure in your manual?

SH230-12 is one of the correct OEM reg/recs. (It's not the Kaw part number, but is the OEM number, and is not necessarily the only OEM reg/rec for that bike.) Your bike uses a 3-phase reg/rec, but the early 550 (79 and 80?) use single-phase, in case you need to get one on ebay.

If it fails the ohm tests for shorts, it's bad, but if it passes all of the tests, it's not necessarily good. The problem with meter tests is the lack of stress on the reg/rec during the tests.

Put the black lead from the meter on the reg/rec's black wire. Ohm checks to all three yellows and the red on the reg/rec should be infinite (or overload etc).

Put the red lead from the meter on the reg/rec's red wire. Ohm checks to all three yellows and the black on the reg/rec should be infinite (or overload etc).

If they show low resistance, they are shorted.
If the resistance is not infinite, but is in the meg-ohm range, and all of the readings are in the same range, then it may not necessarily be bad. Some diodes may have a tiny reverse leakage which a sensitive meter can detect.

You can do forward-bias tests by swapping the meter leads from the above instructions, but the readings will vary quite a bit depending on the meter, so I won't hazard a guess on the results.

I would recommend voltage tests (while the bike is running), over simple ohm-tests. Charge the battery before testing.

Unplug the reg/rec and measure the AC voltage on each pair of yellow leads coming from the alternator, while the bike is running and revving.

At 1500 rpm, you should get around 20v AC.
At 3000 rpm, you should get around 40v AC.
At 6000 rpm, you should get around 70v AC.
These numbers are very round numbers. This tests the stator (unloaded).

Next, connect everything together, then measure the DC voltage at the red wire on the reg/rec using the battery ground for the meter's black wire. Do the same test using the reg/rec's black wire as the ground for the meter's black wire. The results should be same for both. If one is way higher, then it is a wiring problem. If both are similar, but too low, then the reg/rec is probably bad.

I've had very good luck finding reg/recs on ebay, cheap and in working order.

For those who are interested in seeing the actual waveforms from the alternator on a 3-phase kz550:
550 3-phase screen shots

Post edited by: loudhvx, at: 2007/03/02 15:10

Hi and welcome to the site. . .as you can see, maybe some of the help here will point you in a direction to get your bike fixed.

Here's some basic ideas, since the bike is 25 years-old. Have you checked your battery with a votage meter to see what it is right now? I would do that, and then turn the lights on without the bike running for about 90 seconds, and then measure it again, to verify that it doesn't have a weak cell or less than 12 volts. A weak battery will cause weak charging output. With the bike running at 2500 rpm, what voltage are you showing at the battery on your meter?

Do you have accessories added to the machine that might make a difference in load demands on the existing system?

Finally, I would check the wire connections. If they are corroded internally or not making good contact, like where the ground cable connects to the engine (it could be oxidized) you might have a problem with the system that is causing a no/low charging problem.

WOW!! loudhvx and KaZooCruiser
Those posts both have useful stuff that I can print and put in a file so I can find it for future reference.
Thanks

The regulator/rectifier is easy to test in the bike. Start and check battery voltage as the bike is running. ~12.5 VDC at idle and then take the rps up to 3500 rpm and check the voltage. Should be ~14.5 VDC. The voltage has to be in excess in order for the battery to maintain a charge. The reg/rec is tied directly to the battery.