The International CBX Owners Association

I bought a used Kawasaki based alternator conversion for my '79 X. After installation, I did not start the bike until the next day. When I tried to start it the next day, I noticed that the battery was drained.

I replace the battery with a good one and did some troubleshooting. Think I have traced it to the alternator as during my troubleshooting, I unplugged the alternator connection and the parasitic battery drain (when the ignition switch is off)went to zero. Believe this might be caused by bad diode(s). I was able to start the bike and after initial charging voltages appeared to be good (14v), all of a sudden, the charging voltages went to 16v. Also alternator is quite hot after running for 2 or 3 minutes so I feel there may be other charging issues at play here as well.

Any comments or suggestions? Assuming the alternator is serviceable which I believe it is, does anyone know when to get parts?


Thanks. Bill

I experienced something similar when I first installed mine, it overcharged my battery till it killed it. My old wiring harness had a lot of accumulated resistance in it, causing the alternator to go full field. I replaced my wiring harness and cleaned all the other connectors and it has been perfect ever since.

Your conversion MIGHT have been made by J.R. Lukasik.
He no longer offers that product but MIGHT have some ideas/info.
Contact is: cbxtras@gmail.com

Thanks for the replies. I do not believe it is related to my wiring harness, as the stock alternator that I replaced with the conversion alternator was working fine. I just wanted to install the upgrade to enhance the reliability of the bike.

I understand in speaking with Bill at TIMS that Rick's Electric in New Hampshire carries parts for these Kawasaki based conversions. So I will be taking the alternator to a local shop here in Cobourg to have it checked for condition and performance and hopefully confirm the repairs required.

Purchased J.R.'s conversion for my last CBX about 10 years ago when he was still in business and it worked beautifully so this is way I am doing the upgrade on the new ('79!!).

Your alternator is made by Nipondenso.
I had good luck taking one to an automotive rebuilder.
They had the diodes.
Best,
Phil

I am currently having the same exact issue. I thought it was the diodes or possibly the voltage regulator, but they both seems to function normally.

Was there a conclusion or solution to this problem?

I DIDN’T READ THIS POST WHEN IT WAS NEW, BUT JUST SAW YOUR QUESTION. DOESN’T LOOK LIKE THE SOLUTION EVER GOT POSTED. HOWEVER, AS I READ THROUGH THE POST I NOTICED THAT NOBODY POINTED OUT THAT IF YOU GET THE TWO WIRES FROM THE K ALTERNATOR PLUGGED IN TO THE CBX HARNESS BACKWARDS/REVERSED, WHAT WAS DESCRIBED (BATERY DRAIN) WILL OCCUR. THESE CONVERSIONS CAN HAVE ALL SORTS OF DIFFERENT WIRE CODES SO IT’S EASY TO DO. ON THE CBX HARNESS THE ALTERNATOR WILL CONNECT TO THE 3P RED COUPLER AT THE SIDE COVER. THAT COUPLER HAS A RED/WHITE, A BLACK, AND A GREEN (GRD) CONNECTION. R/W IS UNSWITCHED 12V FROM THE MAIN FUSE; BLACK IS SWITCHED 12V FROM THE IGNITION SWITCH, AND SERVES AS THE “SENSOR” WIRE FOR THE ALT REGULATOR. (GRD FOR K ALT INS’T USED). IF YOU HOOK THE K ALT UP AND TURN THE IGN SW ON AND THE VOLTMETER JUMPS TO FULL POSITIVE, THE WIRES ARE REVERSED. LEAVE IT THAT WAY AND THE BATT DRAINS. JUST SWITCH THE WIRES FROM THE K ALT AROUND. WORTH TRYING BEFORE LOOKING INTO REBUILDING THE ALTERNATOR.

Not trying to hijack thread but I have an opposite issue. My alternator (kawa) is only producing 1 volt and about 3 at 4K rpm. Local guy checked and said it may be regulator. I thought purpose if regulator was to keep voltage under 14.5v and not to restrict any production. I don’t have stock harness or ignition. Starter is connected to battery correctly where black wire coming from alt is actually +ve . Windings look good and all three of the stator wires come back good from multimeter continuity and resistance test.

Any ideas ?

Anyone ? I am looking for some basic idea .
I have no factory harness. It is all being wired using m unit and Sachse electronic ignition. Bike runs fine . When it comes to alternator, I am clueless. Want to know how to hook up this denso unit

You need a good electrical guy with testing equipment to be at the bike. Long distance diagnosis on a non-stock machine is an exercise in futility.

The Kawasaki alternator needs to be wired with the battery feed to diode - red wire in the photo. (12 gauge)
An ignition source wired to the terminal just left of the brush holder - black wire. (16 gauge)
I added a dedicated ground to the alternator for insurance - green wire. (12 gauge)

Solder every wire to the terminal or lug.

These 3 wires match up in color to the Honda harness. The original Kawasaki battery feed is black and that's where the confusion can begin.
Additionally, unless you have donor parts on hand for replacements, it's been my experience that for the cost of replacement Kawasaki individual components, you might as well buy a complete used alternator on ebay. The parts generally don't go bad but, when they do, can get costly.

FYI, the regulator is that disc shaped thing on the left and is transistorized.
Brush holder in the center, just above the green wire.

Thank you J.R
I followed your email and did a bench test with a drill.
I connected the field coil to +ve of a charged battery (13.2 v) and used alternator body as ground . The 2nd wire as alternator output. It produced 30Volts :) . Then I connected the alternator +ve output to battery +ve. Immediately I could see the drill bogging down and the voltage on battery terminals was showing 14.8.

Thanks for explaining. What I was previously doing wrong was thinking that field coil wire is a -ve and was hooking that to battery -ve . Result is that I have now 3 good Kawasaki alternators . They should last me a long time

Thanks

The old saying holds true here, "a picture is worth a thousand words"

Cool outcome!

I am learning :) . It has been 11 months only that I have come to know about CBX. Good company here on forum makes it worth.

Thank you CBX-tras for this photo. At last. Some of the conversions out there come with very different wire codes (not even the original K coding) and few and often misleading instructions about linking to the OEM wires.