Spark Plugs

[akira700]

How often you change your spark plugs?

I think my Honda Service Manual says 16,000 miles.
Do you do this more frequently?

[butcher bergs]

I do mine just about every 20k unless there are extenuating circumstances that dictate otherwise....sustained high-revs would be one of those circumstances.

[Jim]

just did mine a month ago @ 20k, and i dont think the previous owner ever changed them.

[Billy]

I have to change mine every 7,500 miles.

[JohnnyV]

I tend to check them periodically(maybe every 5k or so), clean them and throw em back in; then change em when they're shot.

[stoinkythepig]

They seem to last forever in my 9R. I have more than 40,000 miles on the set that's in there and my MPG has not dropped at all. I suspect new plugs would give me a little power at the top of the rev range, for a couple of thousand miles anyaway, but it's not worth replacing them since I rarely venture above 9000 RPM and the plugs are very expensive. My bike takes the plugs with two electrodes (cr9ek) and I think the plug design has much to do with longevity. That said, modern ignition systems are also pretty easy on plugs.

I highly recommend taking plugs out for inspection at the recommended interval, if only to make sure they are properly torqued in place.

[KB]

I had 50k on the original plugs in the Superhawk before the front cylinder oil ring decided to let loose while doing a 70mph wheelie for about a long time.

If it wasn't for the ring failure I'd still be running them.

I replace the entire engine with one that only had 12k on it.

KB

[nerijusj]

I changed mine @ 14k miles on the 636 I had. I thought they still looked pretty good. I'd do them when I do more serious maintenance on a bike and have everything off anyways.

[TLRMan]

I used to change the plugs in my Dragbike every 1/4 mile pass.
Good thing I had a sponsor!

They can, and will last at least 15-20K, and still look good.
All depends on what you are doing with the application.
Turbo, racing machines tend to put it to them a lot earlier.
Always had good luck with NGK BTW.

[brewmaster]

Race bike - once a season (mostly due to fogging the engine after every weekend/track day)
Street bike - once a season just because they are cheap for my bike ($2/ea. on sale and I only need two). That said they have never looked like they have ever needed to be changed.

Just for reference, I changed the plugs in my GTI at 120,000 miles and they still looked good.

However my old Camaro eats plugs like they are candy! This is most likely due to the compression and ignition it has.