I am away from my manual, can anyone tell me when to change the spark plugs on a 2012 Ultra 103. The dealership told me 100K, seems high, very high to me.

Be Safe JIM

 

Just do them with your oil changes. There cheap and can't get much easier to do.

 

+ YEP I change mine every spring with my oil. I pick them up when I pick up my filter from the dealer. $8 is cheap enough to do it yearly.

 

https://www.harley-davidson.com/cont...schedules.html


If I read it right 30K or every 2 years.

 

I change every 10k

 

I do mine in the spring.
Then keep the old ones or one for a spare in my tool bag.

Will they last 100k?
Probably assuming your engine us running properly.

 

Every 5K when I change all fluids.

 

Slightly off topic - are Harley plugs pre-gapped?

 

Manual calls for .038 to .043 - I always gap to .040 which I've found them to be real close out of the box.

 

I switched to the double platinum SE plugs, the silver ones so they match the looks of the originals. While more expensive they will go many more miles and being platinum they really don't wear much so the gap stays nearly the same for lots more miles.