strange overcharging issue

ok, kz400 4in line cylinders.
5 wires regulator. bike overcharge and make the battery boil when i have lights ON . it's the regulator rectifier bad? what i can try?
i have with lights ON 14 volts at idle and 16 volts after 1500rpm.
hepl
i

Fuse box is ok, no melting things or bad wires.

Rectifier = converts power created by the stator into something the bike can use, basically 12V DC.
Regulator = regulates the voltage created by the rectifier to keep it in range safe for battery and other electrical equipment. Ex: rectifier may create peaks of 15, 17, 18 volts - it is the regulator's job to flatten those peaks.

Some bikes have combined units. Since you said 5-wire stator then I believe that you have one of the older KZ400s and it should have a separate rectifier and regulator.

If your battery is boiling and you are seeing 16V then the regulator is not working properly.

Make sure the R/R ground is good. Jumper it over straight to the battery and see if that helps. If not, you need a new R/R.

I said 5 wires regulator, not stator
In the kz400 4 cylinders the regulator/rectifier is all in the same component.
Ok, so you think i have to just replace it?
I wonder if i can test something else

Nessism wrote: Make sure the R/R ground is good. Jumper it over straight to the battery and see if that helps. If not, you need a new R/R.

nessism, if you mean the black yellow wire that goes up to te negative battery lead, yes, the wire it's ok.

shamal wrote: I said 5 wires regulator, not stator
In the kz400 4 cylinders the regulator/rectifier is all in the same component.

Whoops! I guess I need to read better. And I missed the part about 4-cylinder KZ400 too. In my defense I have not finished my first cup of coffee yet so I should not be held accountable for my actions (or lack of).

Yeah, it sounds like a bad unit to me.

shamal wrote:

Nessism wrote: Make sure the R/R ground is good. Jumper it over straight to the battery and see if that helps. If not, you need a new R/R.

nessism, if you mean the black yellow wire that goes up to te negative battery lead, yes, the wire it's ok.

If you are overcharging, the negative lead from a 5 wire R/R going to the battery and making good contact, then you have a bad R/R.