coil impedance

my stock coils have a resistance value of 4.5 ohms..
i found a set of coils i would like to try, but the ohm value on them is 2.5 ohms..i still run stock points and condensers...will these coils work? i want to try them because you can change the wires on these but not on my stock ones.

Not a precise answer to your question, but the following link from Z1E suggests not using a coil with resistance lower than your stock coil (if I'm reading it correctly). The link does list these 3 ohm coils for use on '76KZ900ltd and for '77KZ1000 and for '73Z1.

I've been running these 3 ohm Dyna coils on both my '76KZ900ltd and '73Z1 and am very satisfied, but am wondering about the 4.5 ohms noted in your post (higher than my bikes -- and higher than listed by Z1E).

Anyway, hope this sheds some light on the subject.

www.z1enterprises.com/detail.aspx?ID=210

Post edited by: Patton, at: 2006/11/25 20:52

Post edited by: Patton, at: 2006/11/25 20:54

well, these are the original 1975 coils on my kz900...i'm sure they have went up with age..currently they ohm at 4.5 ohms. what i dislike most is that the wires are formed into the coils..no way to put new wires on them. these other coils would be great is the ohm range is good. thanks for the link, i'll check it out.

Post edited by: arobsum, at: 2006/11/25 22:36

arobsum wrote:

well, these are the original 1975 coils on my kz900...i'm sure they have went up with age..currently they ohm at 4.5 ohms. what i dislike most is that the wires are formed into the coils..no way to put new wires on them. these other coils would be great is the ohm range is good. thanks for the link, i'll check it out.<br><br>Post edited by: arobsum, at: 2006/11/25 22:36

Agree with you about OEM wires being formed into the coils so when wires go bad you're looking at new coils to get new wires (although I saw somewhere a "plug wire connector" to attach new wire to the stub of an old molded in wire -- but never tried this).

When purchasing the Dyna coils, new plug wires are a separate item, but they come with the plug caps already affixed and a conductive clamp which attaches to the other end inserted into the coil.

The Dyna coils bolted right in without drama.

Copper wire core -- black
www.z1enterprises.com/detail.aspx?ID=208

Copper wire core -- sexy red
www.z1enterprises.com/detail.aspx?ID=209

??Graphite?? suppression core
www.z1enterprises.com/detail.aspx?ID=1983

As I understand, the suppression wire core is for use with audio equipment to help avoid the ignition static delivered by the copper wire core (and maybe better for some type of more sophisticated electronic iginitions). Perhaps this is related to use of NGKB8RES plugs (as opposed to NGKB8ES) which are supposed to help eliminate radio interferrence, and maybe the resistance type spark plug caps also. I believe the spark plug caps on the Dyna copper core wires are the straight through type and not the resistance type. In any event, the Dyna coils and plug wires deliver a healthy fat spark, and since installing them I've had no further ignition spark issues.

Post edited by: Patton, at: 2006/11/25 23:23

You can use the low resistance coils by putting a resister inline to increase the resistance.

Very interesting thread here:) Anyone know what the blue Andrews coils should OHM at? I just bought a pair and see they're about 4 OHM. Sound right for stock points ign?

I have a set of those black copper core wires that Jeff has and they are good quality, recomended:cheer:

Regards,
Ray

The lower the resistance of the coils, the more heat is dissipated at the points. The more heat that is dissipated, the more metal is transferred from point to point. Bottom line is that the points wear out much faster with lower resistance coils. I know one ohm does not seem like a lot, but the current increases by 60 %. Power dissipation increases by the square of the current so the heat increase is considerable when going from 4 ohm coils to 2.5 ohm coils.

Impedance is not really an issue. Resistance is the issue. Since the coil-current reaches a DC state rapidly at idle, it becomes a simple DC-resistance problem. Therefore, as Steell said, you can simply just add some resistance. About .5 to 1 ohm should be fine. It's not very energy efficient, but should work, and is cheap, which is what I presume is the goal.

Post edited by: loudhvx, at: 2006/11/26 02:05

Patton wrote:

As I understand, the suppression wire core is for use with audio equipment to help avoid the ignition static delivered by the copper wire core (and maybe better for some type of more sophisticated electronic iginitions). Perhaps this is related to use of NGKB8RES plugs (as opposed to NGKB8ES) which are supposed to help eliminate radio interferrence, and maybe the resistance type spark plug caps also. I believe the spark plug caps on the Dyna copper core wires are the straight through type and not the resistance type. In any event, the Dyna coils and plug wires deliver a healthy fat spark, and since installing them I've had no further ignition spark issues.<br><br>Post edited by: Patton, at: 2006/11/25 23:23

Patton,
Are you saying suppresion wire should be used if you have electronic ignition? As in stock electronic ignition with the manual advancer? I need to know...

Kent:whistle:

del

OKC_Kent wrote

Are you saying suppresion wire should be used if you have electronic ignition? As in stock electronic ignition with the manual advancer? I need to know...

Here is info from the Z1E listing --

Dyna Ignition Wires - 7mm Suppression Core (Black)...
DYDW600 Dynatek Black 7mm Suppression core wires with plug caps, rubber boots and connectors...Dynatek "Dyna" Wires are available with a solid copper core for use on older vehicles where electrical interference is not an issue. For use on new vehicles with electronic advance ignitions or other sensitive electronic equipment use DYNA suppression wires with a high grade graphite core for best performance and electrical noise suppression.

I'm guessing a little, but believe the relatively simple and easy to install Dyna S timing plate used to replace the points plate is not an electronic iginition (or a CDI either) and works just fine with copper core plug wires (might also be okay with graphite core -- but why gamble).

Dyna also produces the more expensive and sophistocated Dyna 2000 which is billed as a programable electronic ignition, with use of graphite core recommended -- see following link:

www.z1enterprises.com/detail.aspx?ID=368

When listening to a portable sound source with ear speakers (from my old tape cassette days while touring), the "R" plugs and graphite core wires seemed to help reduce static interference from the ignition. Don't know how ignition static might affect music listening from compact disk or modern ipod units.

Forgive another guess, but I believe your stock ignition with manual advancer is very close to the Dyna S unit (and perhaps uses copper core wires from the stock coils -- and maybe even resistor type plug caps for reasons I don't understand). If your stock plug wires are graphite core, I don't understand the reasoning behind that either. Just old fashioned perhaps, but I like copper in my wires.

Post edited by: Patton, at: 2006/11/26 10:45

Post edited by: Patton, at: 2006/11/26 10:47

This old 750 F1 has a yellow silicone graphite wire on it, and maybe three stock wires, it's hard to tell. The PO had two plug cap wires off and the copper wire was wound around the plug top!:blink:

Thanks for the tip!

This gets a little complicated

The Dyna S and the Kawasaki KZ (till at least 83) are electronic ignitions, but they don't have electronic advance. I believe the 83 GPz series was the first to use electronic advance. If the bike does not have points, then it has electronic ignition. If the bike has a mechanical advancer, then it does not use electronic advance.

Similar, but different systems