two questions? dry battery/battery eliminator

i am building a kz650 cafe bike and i was wondering if anybody knew where i could find a very small dry cell battery that would work on it. or my other option is to get a battery eliminator but i have installed an electronic ignition on my bike and i'm not sure if a battery eliminator will work with it? help

Which electronic ignition? The stock Kaw electronic ignition is very efficient on power. The Dyna S, on the other hand, uses much more power than stock (most of which is wasted at lower RPMs).

i have a dyna on my bike. i saw that dutchz had a really small battery on his bike. it looks like it was on its side so i'm guessing it is a dry cell battery. so do you think a battery eliminator wouldn't be able to work on a bike with a dyna ignition?

I haven't tried it, so I can't say for sure, but I'd be afraid the voltage would drop too low at idle, especially with the lights on.

I have a big (for a capacitor, but small for a battery) capacitor on my 1978 KZ650B. It seems to run fine at idle with all the lights on. I would like to switch to LED tail lights and blinkers to further reduce the load. I also have a Dyna S with WiredGeorge's hack.

i have the same setup you do for my ignition. where did you get your capacitor and how big is it? i am trying to make this thing look as minimal as possible. also where can i find a diagram for the wiring mod. i looked in the filebase and i can't find it? thanks alot

Post edited by: dnestell, at: 2007/04/02 14:32

The diagram can be found on WiredGeorge's site. Just do a search for his username and I believe it's in his user profile. If not, he could give you the address...

I knew SOMEONE would ask me what size capacitor I have. The bike is in storage for the winter a good hour away from where I live. I recently got an email from the website I ordered it from that it is now obsolete. But here is the info on the capacitor...

Discontinued Item:
Manufacturer Name: CDE MALLORY
Manufacturer Part Number: CGS562U075R4C
Manufacturer Discontinued Date: 02/01/06
Newark InOne Sku: 07C9742
Last Time You Purchased this item: 05/02/05

Product Description: Aluminum Electrolytic Capacitor Capacitance:5.6mF;
Capacitance Tolerance:+75, -10 %; Working Voltage, DC:75V; Terminal
Type: Screw; Series: CGS; Features:Computer-Grade

Loud will probably have something to say about this. My bike starts up VERY well off one kick, so if Loud could give you some advice on a bigger capacitor, that might work best. I turn off my headlights when I kick it, but at idle it can run my headlight, my running lights (my turn signals are dual filament bulbs, and also serve as running lights), any two blinkers or all four for hazards.

I don't think I tested trying the horn under load. Like I said, my worry was getting TOO big of a capacitor and it not being able to charge in one kick. Since it seems to startup okay, I would suggest trying to goto a little bit bigger of a capacitor. I think I'm on the line as for how much load I need and can use.

-- Craig

Post edited by: Corith, at: 2007/04/02 14:48

i have seen capacitor made by accel on ebay and on the accel website. i wonder if one of these capacitors would work?

Yeah, I also used the same size cap on my 550 to go battery-less. That's 5.6 milli-farad (5.6mF), also known as 5600 micro-farad (5600uF).

(Watch out for confusion because sometimes people use mF to mean micro-farad, but that would be improper. The abbreviation for micro-farad is uF, where the u is a actuallly a substitute for the greek letter "mu" which actually looks like a cross between a "u" and an "m". Confusing enough yet? )

You'll want the cap rated for around 50v (higher is better, but 50v should be fine).

The issue of charging the cap in one kick is a concern. Since the stock 650 with points only uses one coil at a time, it uses about half the current as the Dyna S. The Dyna S has both coils on almost all the time. Try it and see is probably the best way to find out.

If the bike is hard to get started with a good battery (kickstart, that is), it'll only be harder to start with a capacitor.

If it starts in one kick pretty reliably, then the capacitor has a good chance of working.

By the way, for anyone else reading, the battery eliminator is not eligible on a 77 650 with stock charging system. That bike needs a battery (however, it can be very small).

Post edited by: loudhvx, at: 2007/04/03 02:11

another question. i also have 2 kz400 one 76 and one 79 is there any problem with using a capacitor on these bikes?

The 76 kz400 will need a battery. I can't say for sure about the 79, but I think a capacitor will work on the 79.

Generally speaking, on the 650 and 400 KZs, the way to tell is to look at the alternator cover. Notice on the 77 650 and the 76 400 that there are three screws in a triangle shape in the center of the cover. That means it needs a battery to work.

If there are no screws in the center of the cover, you can get away with a capacitor.

what do the three screws signify? does it have to do with the type of charging system. aren't there constant magnet and non constant? magnet charging systems? sorry for my lack of knowledge about these things i am kind of just getting the hang of electrical systems on bikes and in general.