Regulator question

No eBay APP ID and/or Cert ID defined in Kunena configurationHi Guys. After blowing another coil and pickup after 3 days perfection of a running bike, I finally know that my problem is high voltage. I found a bunch of regulators on ebay but I don't want to buy another used one just to be sure it finally works. Those coils and ignitions are pretty expensive (Accel Super Coils and Dyna S).

So anyways beside the OEM ones I found this one which also have 6 cables in the same color. Here my problem though: I don't have those connectors on my bike anymore. They are just directly connected and the brown cable goes nowhere.



- So if I buy this aftermarket regulator, how do I know which of the yellow cables go where? Or doesn't it matter?

- Also where does the brown cable go usually?

The Brown wire being disconnected is your reason for the high voltage. This is the voltage sensing wire, and needs to go to a switched key on power source that is with in .5v of battery voltage. Hook that up, and re-test your voltage across the battery at 4K RPM. It should be under 15v for sure, around 14.6v or something close.

I'd imagine every light bulb has been stressed to the end of it's life too.

Motor Head wrote: and needs to go to a switched key on power source that is with in .5v of battery voltage

sorry if i sound like a beginner but where it goes exactly? that entire bike was one big mess. it was running the wrong coils for the ignition i had and the harness was a nightmare of cables. i replaced the whole harness from scratch except for the part that goes to the regulator.

oh and just to be sure i measure it correctly. where do i check for the voltage? at the battery or the cable that charges the battery?

The brown wire is called a sense wire. It senses the voltage on the 12V system, and adjusts the charging voltage accordingly. There are many points in which the voltage may be checked, including the tail light.
If you do not have one, a wiring diagram (color is by far the best) will show you which wire would be best for connecting your sense wire.

KZRider's FILEBASE includes several wiring diagrams for the various 1981 KZ750 models.

What is the particular model at hand?

Good Fortune!

is a kz750 ltd 1981.to the tail light sounds good, that's near. i will try that.

now where is the best place to measure the voltage? directly at the battery or at the cable that goes to the battery to charge?

Check the voltage at the battery. The manual has the procedure w photos --- a good battery should be ~12.6 VDC & with the engine running ~14.5 VDC @ 4000 rpms. The battery should be good & fully charged beforehand. Also, warm up the engine to obtain actual operating conditions for the alternator.

You can check the alternator's output by disconnecting the three yellow wires --- check them in pairs, 3 tests total --- battery charged & engine @ 4000 rpms --->>> ~50 VAC (be sure to set the multimeter to the AC voltage scale).

When you reconnect the 3 yellow wires to the voltage regulator, the order doesn't matter but you must match yellow to yellow

Voltage regulator. You can use the reg-rec from a Ninja 500 or Vulcan 500 up to 2009.
I installed one from a low mileage 07 Ninja 500 (eebbaayy ~$25)(credit to loudhvx).

Well Im very lucky. Someone from the forum here will send me another pair of the Accel coils and a regulator for free to test. But first thing I do now is attach the brown cable to the tail light and go downtown to test the voltage. I don't have a multimeter here.

RadioShack carries very inexpensive multimeters --- you can probably get one for $10 or so.... maybe less. I use a VC97 digital multimeter & Ctek US 0.8 charger.

If the reg-reg doesn't have a connector, you could get a connector set & new terminal pins from Z1Enterprises.com or CycleTerminal.com or somewhere.

Im going now to a car repair in town to use their multimeter. I attached the brown cable to the rear light. I don't need the connectors, I was just unsure if it matters which of the yellow cables goes where, but you already answered that question for me I usually weld the cables.

i just had a chance to get my hands on a multimeter and wow... i attached the brown cable to the rear light but the regulator seems to be dead. i had 12.60v when the bike was off. as soon i turned it on it went over 16v within 10 seconds even below 4000rpm. i already have a regulator on the way, used but for free and i will check that one. in the meantime i will disconnect the regulator cable to the battery for short distance to work today and tomorrow.