Eliminating battery KZ750b twin

Due to a blown head gasket on my '79 twin, I am currently going through my entire bike. As we all well know, the wiring on these bikes wasn't the greatest, and due to the patches done by a previous owner(s) the wiring on my bike is in shambles anyway. To add to this, the starter is broken. So now I would like to strip out all the nonessentials on the bike, including the starter, battery, turnsignals, etc, and run a dead simple wiring harness.

So my question is will I need to do anything special (like add a capacitor) to allow the bike to run without a battery and the points ignition? Or is it even possible?

So I take it, the twin isnt too hard to kick over

It can be done. With a capacitor I believe is how it was described before...
U can do a search here, possibly find the info. LouDVHX will probly have a diagram of this...

Someone with more specific knowledge will be along for sure.

Good luck.

Yeah it isn't too hard to kick over, the worst part is the bruises from the lever kicking back. Of course since my headgasket was leaking compression, maybe it will be worse when I have that fixed.

On a side note, anyone know about a starter elimination as well, I'm wondering if all I need to do is plug the hole where the snout meets the engine and of course remove the starter chain. In this situation the starter gear on the crank will free wheel. Or if there is something else I am missing.

You have it right, remove the starter and chain and upper gear, and leave the sprocket on the crank.

There's an oil hole in the crank under the sprocket, remove it and you'll lose oil pressure.

There's at least one thread with directions for ditching the battery, just do a search.

Yes, the 79 KZ750 B4 twin can potentially go batteryless because it uses a permanent magnet alternator. The battery will have to be replaced by a big capacitor. Something like 5000 to 10,000 microfarad, 50 to 75 volt capacitor should do it. This is neede to smooth out the pulses so the regulator can work properly.

But there are some other things that you need to reconfigureas well.

If you have a reg/rec that has a brown wire (not stock for that bike), then the brown wire has to be tied to the red/white output wire. This is to prevent blowing up the capacitor.

Also, you will need a way to shut off everyting electrical on the bike during startup, except for the ignition and the reg/rec. That basically means wiring it so the all of the lights can be turned off for starting. Then you give a quick blip of the throttle and turn the lights on.

Before, removing the battery, make sure the bike can start in one easy kick every time. If not, it's only going to be tougher to start without the battery.

The last thing is that you might want to bump up the idle by 100 RPMs or so. This reduces the potential for stalling.

Ok, well another side question, if I swapped the electronic ignition from a newer twin, would I then need a battery or capacitor to start the bike?

Thanks

kro10000 wrote: Ok, well another side question, if I swapped the electronic ignition from a newer twin, would I then need a battery or capacitor to start the bike?

Thanks

Yes. You will still need a capacitor or battery in order for the regulator and ignition to function properly.

In order to totally eliminate batteries and capacitors, you would need a very different type of regulator, and would need a magneto type ignition (which are cool, but not as reliable or easy to live with as the factory ignition).

(Even an aftermarket CDI type ignition uses a capacitor.)