Standard plugs every 10-15k usually. I log a buttload of miles, so 10k is about 4 to 6 months for me.

 

Thanks for the advice. My bike had battery issues and I replaced the battery about a month ago as it was cranking slower than it did in the past. It now cranked better but still needed to turn over two or three times to start. After pulling the plugs I noticed they were a lot dirtier than I expected, especially the rear one. They were the style with the super small electrode. As it was nearly 9:00 I went to a local auto house and picked up a set of Autolite plugs that crossed from the 6R12 mumber. The bike now starts on the first roll over. That problem is solved and for the $4.65 cost I will watch the back plug and go with the more frequent replacement.

 

I change them once per yr or 10k miles whether they need it or not. Spark plugs are cheap (even the NGK iridiums) and easy to replace. It makes sure your bike is running well and the spark plugs do not sieze up inside.

 

Once a year and carry a set of new.
Tims' Dyno-less tune

 

It's amazing that we change the plugs so often compared to newer cars being changed at 100K.

 

The service manual calls for replacing them every 10k miles. Since I ride around 10-12k miles a year I just replace them every spring. Also carry a spare set in case needed.

 

10K which for me is about once a year. I always put on a tad bit of anti-sieze as well to make removal easy next time.

 

Good point, but maybe that's because in most cars, it's a horrible nightmare to change plugs. Wife had (emphasis on HAD) a Mitsubishi Montero that cost $800 for a plug change because some genius engineer decided to make a requirement for the entire engine intake to be removed in order to change the plugs. Or, we have been convinced by the MoCo into spending $ on plugs by them telling us we need to change them every 10K...

 

I pulled the plugs on my Streetglide at 18,000. I replaced then but they didn't look bad. Cars now come with platinum plugs that go 100,000 miles. Harley will sell you platinum plugs too and recommend that you change them every 10,000. Why? For the same reason their oil and laundry sells for inflated prices. The dealers profit comes from service and selling doo dads. I'm an older guy and remember when a motorcycle shop was a gathering place for guys. It was full of motorcycles and smelled like oil. Now they have few bikes and a ton of clothes for the chicks who wobble in on their Sportsters and Deluxes to go shopping. It's about selling stuff you really don't need. You know they sell you a "lifestyle."

If the electrode isn't worn and the gap is good why change out a perfectly good plug?

 

I replace mine every 5k, or once a year.