Kz750 twin 76 charging issue

Here it is: battery voltage is fine pre ignition. Reving up voltage goes to mid14-15. I follow wiring diagrams supply on here and in about a week ish of riding ( i ride daily ) the battery slowly dies. I dont run starter. Kick start only. Led headlight and taillight. One toggle switch control the circuit so when the bike is off there isn't a open circuit... and it does the same with 2 battery. One new from last fall.

Plz feel free to put any diagram that could help.
Thx

What rpm is the engine idle speed set to? Ed

lobe kz650 81 wrote: Here it is: battery voltage is fine pre ignition. Reving up voltage goes to mid14-15. I follow wiring diagrams supply on here and in about a week ish of riding ( i ride daily ) the battery slowly dies. I dont run starter. Kick start only. Led headlight and taillight. One toggle switch control the circuit so when the bike is off there isn't a open circuit... and it does the same with 2 battery. One new from last fall.

Plz feel free to put any diagram that could help.
Thx

No ignition switch?
Steve

Around 4000. I ride the bike daily...it kick start everytime.

And. No ignition switch. Just a main switch to open and close power to coils

lobe kz650 81 wrote: Around 4000......

If you're saying it "idles" at around 4,000 rpm you have more serious problems than the battery. 4,000 rpm is not even close to idling. Idle speed is to be set at 950 - 1050 rpm, so your bike is not idling, and that problem should be diagnosed and corrected before damage is done to the engine. Ed

If your main switch only turns power off to the coils, but leaves power on to everything else, that could explain why the battery dies.

You have a field coil that is probably using full power whenever the main switch is turned off, not to mention the lights, based on your description.

Ok. It make sense loud. But no it doesnt idle at 4000 rpm. Sorry for the misinformation. It idle just fine at 1125 ish to 1250.

Could u post a diagram?

My switch is indeed between my positive and engine coils. It control both my lights. But what im wondering is why it doesnt charge enough to keep up with the drainage (cant be that much!) Of the field coil...

If i move my switch right before my positive pole then i should be ok !?!

Thx for ur patience and guidance. ..and ill post a pic soon. Just need to take a smaller one

The 76 and 77 Kz750 twins have a very unique charging system They use a field coil-alternator like other Kz's, but they control the negative side of the field coil with a solid-state regulator. That is not found on any other Kz's and is not directly swappable with other Kz's unless you reconfigure the wiring a little bit.

( www.Oregonmotorcycleparts.com has the correct regulator for your bike.)

Here is a simplified diagram I made for another member.

Thx u very much. Does the field coil is part of the stator or is it on a separate unit on itself? What i got is very similar to the diagram u just posted because i base my wiring on another diagrams of your from a different conversation. Im heading to revisit my wire right at this moment.!

I think you have the typical Kz, excited-field alternator. Normally, that's where the field coil is stationary, and is mounted to the alternator cover. The field coil fits into the rotor, which spins to invert the magnetic field. The stator is mounted to the engine case, and sits around the rotor and field coil.

Your service manual should have directions on how to troubleshoot the charging system. Typically, you measure the output of the stator while grounding the green wire form the field coil. But that is after you do voltage/rpm tests on the battery and rectifier output.