[skull2007]

I really would appreciate any advice on selecting wires. i have a 06 softail with a 1450 with efi. And why are they so expensive. is they any thing special about them. I'm told not to use fat wires, or braided stainless or the ones with led lights.

how long do they last?

[Clem]

Plug wires should last 30 to 50 K miles without any problem. The best wires are the silicone insulated 'name brand' ones. Screaming Eagle offers one of the best wires accepted by Harley Davidson.

The wires are not actually wire. They are a conductive matrix of carbon and some other elements to conduct the high energy of the coil without allowing the coil to actually short circuit with the ionozing spark. The spark energy must be 'ballasted' to prevent spark-over within the coil (transformer) which will destroy the secondary windings (output). That is also why it is very important to never allow the coil to spark while unattached to a plug or away from a ground return for the spark. The coil will spark inside and destroy itself.

Good wires are not cheap and since they perform an important task with specific design, they are worth every dollar. Cheap wires will cost much more!

Bill C.

[kenfuzed]

Some wires, especially those for race use, can cause electrical interference (RFI) to electronic fuel injection components. Often the problems are intermittent after switching to these wires. I would stick with wires that are designed for EFI and avoid any fancy or flashy wires. Good wires are made to minimize RFI by way of their suppression and overall construction, which is why they are so expensive.

Braided wires are the worst when it comes to RFI and will reek havoc on an EFI equipped motorcycle.

[Clem]

Never saw shielded plug wires on a motorcycle...aircraft, yes, but not automotive high tension leads. The RFI is suppressed by reducing the high tension spike from the coil. That is done by either a ballast in the spark plug (a resistor), the plug connection cap, or the lead itself by impeding the spike of high voltage to a degree. Also, creating a surround for the entire system (hood and engine compartment of a car) is more effective as a blanket to RFI. Shielding a high tension plug wire is not so easy since very few pliable insulators (such as teflon) will resist ionizing and creating a path of discharge, most especially with the super high output ignition systems that are in use today. Even silicon becomes porous at super high energy levels and will ionize allowing a path for discharge.

Bill C.

[skull2007]

another question i have is, are they any different from the plug wires we use in our cars? for thirty bucks you can get 4-8 of them.

[Clem]

That's hard to say without knowing more about the specific ignition system of the car. The differences are the type of conductor and the plug boot and coil connection since there is no standard. The plugs used in the HD are very small compared to some automotive applications, the plug boot would not form the shield nor would they stay attached properly. Ignition supressive wire comes in different resistances per foot and that is basically why you should buy the wire assemblys specifically intended for the year and model of your motorcycle. Second guessing these wires will cost you much more in the long run....

Bill C.

[skull2007]

Well that's cleared up now. I think i'll go with the SE

[Clem]

Good choice. But, the standard HD plug wires are fine quality too...

Bill C.