New Coils and thier wires

[Jethro]

My new Dyna coils should be in tomorrow, along with a set of Taylor wires. One thing I didn't ask my shop guy was if the caps will be compatible with terminal stud sparkplugs. To you guys that have changed out coils or wires, did you have issues with this? Can I just screw on those nuts to the plug itself that makes the plugs like my car, with a snap stud? Are there different size caps for plugs of different sizes? I know the terminal stud plugs are kinda rare these days.

[mark]

The wires that Z-1 enterprises gave me to go with my Dyna coils had the standard automotive end (don't know if they are Taylor though). Nothing like NGK plug caps. I was amazed to discover that in the box were also included the 4 little caps that you could screw on to the end of your plugs so they would fit. Just regular automotive size I believe.

They have the same kind of end that goes into the coils. Cut and solder to the right length and your done.

[dietcokeking]

I wanted to maintain the stock look, so I installed my NGK caps on the Dyna wires.

[yogib]

The caps should have come with the plugs floating in the box.If you have some lying about they should work.Don

[mark]

I wanted to maintain the stock look, so I installed my NGK caps on the Dyna wires.

That's a good idea. Those of us who are modifying our points ignition would have to go from 5 ohm to 3 ohm caps however, since the Dyna coils that go with the Dyna S are 3 ohm coils.

[dietcokeking]

That's a good idea. Those of us who are modifying our points ignition would have to go from 5 ohm to 3 ohm caps however, since the Dyna coils that go with the Dyna S are 3 ohm coils.

I see. I'm solid state. So, would the included Dyna caps have a known resistance value?

[Carter Turk]

I just put in my replacement Dyna coils yesturday. They lasted only 10 years.

The other end of the wire going into the coil required a pronged copper fitting, that was not provided when I bought the coils alone.

They sort of snap into place, with the copper fitting wrapping around the end and sides of the wire.

I had to find these at an electric automotive parts store.

They maybe included with your wires though.

[mark]

I see. I'm solid state. So, would the included Dyna caps have a known resistance value?

I don't know. Should measure it sometime and see. And the caps I have aren't actually Dyna....I don't think Dyna makes spark plug wires........

[wiredgeorge]

Dyna does indeed make 7mm plug wires. These wires come with the fittings to directly press fit into Dyna coils. These wires come in black, blue and red. www.z1enteprises.com stocks all of these colors I think. The plug caps are not impedence rated as far as 3ohm or 5ohm. ALL points style and Dyna S ignitions originally used or need to use coils with a 3 to 5 ohm primary resistance. Dyna 3 ohms coils are actually 3.8 ohms when new. The plug caps, on Dyna wires use the stud nuts that are provided and install on your plugs. This doesn't mean they are 3ohm or 5ohm or any specific impedence I think. In any case, SOME plug wires and caps are resistor type and some non-resistor type. These must be matched to the correct type plug. For instance, if you use an NGK B8ES plug, you should use non-resistor type caps/wires and if you use an NGK BR8ES plug which is a resistor type in the same heat range, you need resistor type wires and caps.

The MAIN difference in coil types other than the wire configuration (some have two outs for plug wires and some one) is their primary resistance. Older bikes that originally were fitted with points and still have the points or a Dyna S ignition can use either 3 ohm coils or 5 ohm coils. Some bikes, using an IC igniter and inline ballast resistor will use 2.5 ohm coils because the inline ballast resistor adds the needed primary impedence and OTHER bikes, especially more modern bikes with CDI type igntions have much lower primary impedence coils in the ~ 1.2 to 1.5 Ohm range. Using the wrong impedence coil will either give you very poor spark or very very hot coils.

[mark]

Dyna does indeed make 7mm plug wires. These wires come with the fittings to directly press fit into Dyna coils. These wires come in black, blue and red. www.z1enteprises.com stocks all of these colors I think.

Those must be the ones I have. Thanks for the good info.

[wiredgeorge]

I sure hope so because I have bought about 25 sets of those darn wires from Jeff in the past year or so bwhahahaha Also, regardless of what anyone tells you, red or yellow plug wires DO NOT MAKE YOUR BIKE GO FASTER!

[mark]

I sure hope so because I have bought about 25 sets of those darn wires from Jeff in the past year or so bwhahahaha Also, regardless of what anyone tells you, red or yellow plug wires DO NOT MAKE YOUR BIKE GO FASTER!

Darn it. I was sure my red ones gave me a few more rpm's.

[lapls]

In any case, SOME plug wires and caps are resistor type and some non-resistor type. These must be matched to the correct type plug. For instance, if you use an NGK B8ES plug, you should use non-resistor type caps/wires and if you use an NGK BR8ES plug which is a resistor type in the same heat range, you need resistor type wires and caps.


Hi,
Are you sure about that? On XS650 list I remember an explanation saying that if you use "R" plugs, then the cap should NOT be of the resistor type, but if using non-R plugs then the spark plug cap must have the resistance ( was 5ohms in that particular case..) . There is also a lot on contradictory information on the Web about that..

I guess the point is... Does all those resistor-type elements add up? I believe so..

The Clymer manual for my bike is useless about that, to test coil problem they just say to swap the coils.... I guess I don't need a Service Manual to tell me this :-)

[wiredgeorge]

A factory tech would use a specialized coil tester that few shade tree mechanics have access to... What happens to coils to cause them to not function is that they fry over time. Being as they are hidden under the tank, they tend to warm quite a bit. The first problem with warming is the coil cases cracking. When this occurs, the coils work great until it rains or there is a lot of moisture/humidity in the air. Then they short... The second heat related deal is that the windings inside a coil (there are PRIMARY AND SECONDARY WINDINGS) are coated with plastic stuff so they don't touch. When they touch, they short. Given they are plastic coated and plastic melts, shorts occur. The shorts can occur in the primary OR secondary windings or both. Plus the shorts can be SPORADIC meaning they don't short all the time. The former situation is a true pain to diagnose. You can check the primary windings by checking impedence. Use a multimeter in 1x ohms scale and put the probes on the two wire inputs to the coil. On a 3 ohms coil, this will read about 4 ohms. This means that the primary windings seem OK (unless there is a sporadic short). Pull the plug wires and touch the contacts in the coil where the wires seat with your probes while the meter is on 20K ohms scale. You should get between 11K ohms and 16k ohms depending on the coil type. This means the secondary windings are OK... Now what if you get NOTHING or a very inappropriate resistance? Like the primary windings give you 15 ohms? The coil is junk. Swapping coils tells you if a problem moves... For instance, you have no spark on 2/3. Swap coils. If the problem moves to 1/4, you can guess either the coil or its wires/caps are bad. Since it is far more likely the coil is bad than both wires and their caps, the coil becomes suspect. Swapping coils is still a good troubleshooting technique. Checking impedences is a dandy technique on a project bike you haven't gotten running yet...

[dietcokeking]

In any case, SOME plug wires and caps are resistor type and some non-resistor type. These must be matched to the correct type plug. For instance, if you use an NGK B8ES plug, you should use non-resistor type caps/wires and if you use an NGK BR8ES plug which is a resistor type in the same heat range, you need resistor type wires and caps.

So, I'm running new, OEM spec NGK caps and plain wires. These would be resistor caps, correct? I would have thought I'd need plain plugs with resistor wires or resistor caps, and resistor plugs with non-resistor wires and non-resistor caps. Please clarify! Does anyone know of a website that addresses this issue? Thanks.