Spark Plug Wires

[Donvito]

The spark plug wires on my 87 are original with about 49K miles. The bike is running fine but I'm wondering of I should change the wires? I'm planning on some long rides in the coming months and I don't know if a wire can suddenly go bad. Can I expect improved performance or gas mileage from replacing them? I've read that only the insulation can go bad so can I re-insulate the wires?

 

If I do replace them, there is a set on ebay, http://www.ebay.com/itm/390644407359 and I would like to hear from someone who's used them. They has lots of positive feedback.

 

Also, I'm reading conflicting opinions on dielectric grease. Someone recommended using it on the spark plug wires contacts to the coils and spark plugs a while ago. What are the correct applications for it?

[IH Truck Guy]

They make great wires....

[Peder_y2k]

You can check the condition of your plug wires IN THE DARK by starting the engine and closely observing each wire over its entire length. If you see any blue hazy glow, or a blue web effect, or spark lines, the cables are bad and need replacement. You can also use a long screwdriver to lighty move each wire and see if there is any spark or blue colored effect. If nothing out of the ordinary, then the wires are OK.

-Pete, in Tacoma WA USA

[GeorgeS]

The plug wires on these bikes, is just 7MM Solid Copper standard spark plug wire.

 

You can get it in bulk at most autoparts stores. Its easy to change the wires, it just screws out of the coils, and the resistor caps.

[lsutley]

I have a set of nearly new wires and caps from my 86. If you are interested send me a PM.

[bongobobny]

I would replace them. With that age, why wait for them to fail?!!?

[Marcarl]

Make sure you use the wire type not the carbon type.

As mentioned, ignition wires by the foot is rather cheap, probably cheaper than the shipping on anything from e-bay.

Make sure to reuse the double jacket that you'll find on the old ones.

[Donvito]

Thanks to all, I decided to replace them. The set on ebay was only $40 with shipping and includes NGK resister caps.

 

Still wondering about the use of dielectric grease. Do I use it on the wire plugged into the coil or only on the insulation? Should it be used on the spark plug where it attaches to the wire cap? Inquiring minds want to know. Thanks.

[Marcarl]

Thanks to all, I decided to replace them. The set on ebay was only $40 with shipping and includes NGK resister caps.

 

Still wondering about the use of dielectric grease. Do I use it on the wire plugged into the coil or only on the insulation? Should it be used on the spark plug where it attaches to the wire cap? Inquiring minds want to know. Thanks.

Dielectric grease is a lubrication product that is non-conductive, so good to use on the boots to stop any cross firing from the cap to the outside of the plug, but tends to stop current flow if you put it on the clip that attaches to the plug. So it great stuff to keep current where it belongs, but does nothing for current flow.

Regular grease on the other hand can allow current flow, so is not suggested to use where loss of current to other components may be in-desirable.

So use a bit of dielectric on the boots to keep them from sticking and keep the current in it's place, but try not to put it on any connections.

[camos]

Dielectric grease is a lubrication product that is non-conductive, so good to use on the boots to stop any cross firing from the cap to the outside of the plug

Speaking of boots, do new ones come with new caps or do you have to get them from somewhere special?

[Donvito]

The set I purchased come with the boots. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&vxp=mtr&item=261269235287

 

I looked on the parts diagram and I don't see a part number for the piece that attaches the wire to the coil. Should I use the old ones or are they available elsewhere? Should I replace them or reuse the old ones?