+1 It's a cheap and easy tune up.

 

i carry a spare set in the tour pack and change them if they don't

work anymore. i don't keep track of mileage numbers. if it ain't broke, don't fix it.

 

Same here

 

Every 10k like the manual says for me.

 

Trust me you are throwing away good plugs. When I use to run a shovelhead I would change them about every 5000 miles, sort of the same for my old '66 chevelle.

With electronic ignition 10,000 is really nothing. They should go at least 20k+. I guess the factory wants to move some plugs.

My Heritage will turn 20k any day so I guess I will change them. I looked at them this spring and still nice gap and fairly sharp edge on electrode.

Will be happy to take those just broke in 3k plugs off your hands.

 

Change mine every oil change.

 

Amen Brother.

 

My service manual say every 20k on my 09 SG. My 05 FLHT was every 10K.

Dave

 

10K here. Normal stock plugs.

 

20K Standard HD plugs (per 08 service manual) ... no difference in the way it runs before or after the change ... They still looked like new ... sharp edges and light tan color