Modern silicone jacketed plug wires don't need to be replaced every three years. And there is nothing all that special about the harsh conditions a Harley plug wire endures, try spending 100,000 miles with the wires on your car or truck. Speaking of which, check the maintenance intervals for most cars and trucks and you won't find short intervals for wires, and in most cases you won't find any mention of them. Plugs vary from 60k to 100k intervals these days, and it makes good sense to inspect the wires at the same time. But there is no instruction to automatically replace the wires.
We have become a throw away society, and the folks who are supposed to work on and fix our vehicles have mostly become a bunch of part changers. If you really want to know if you need to change your plug wires, inspect and test them. Unless you have abused them by pulling on the wire instead of the boots, I'll pretty much guarantee you they will still be just fine after three years, and plenty of us have been running the same wires for more than twice that amount of time with no problems whatsoever.
If you can still find someone who knows what an oscilloscope is, ask him about how you can easily check the entire secondary ignition system with a simple scope.
btw, if you're just looking for an excuse to buy new colored wires to match your bike, you don't need to use the maintenance schedule to justify the expenditure. As far as Harley mods go, a set of wires is cheap.
Jerry
Author
Topic: How often do you change your plug wires? (Read 10356 times)