I'm not fighting anybody. Just trying to help people out with a question.

And it's these type attitudes that have driven away the wealth of knowledge that used to be available on this Sporty Section. If I seem a bit chippy from time to time, that is why.

 

Specs change all the time though. For instance my 2000 Silverado use to call for copper gapped @ .060 in the service manual, owner's manual, etc. They have since changed that spec to Iridium gapped @ .040. It definitely idles much better, not sure about the rest.

 

Well, guess I'll weigh in on this. On my Fatboy, I used to run the split electrode Screaming Eagle plugs which I think have been discontinued, and they made a noticeable difference in performance. I switched back and forth with stock plugs several times to confirm, and it always rang true. That said, I just changed from stock Harley plugs to NGK Iridium, and I swear the bike didn't seem as responsive. I'm changing back to OEM plugs this weekend.

 

Sorry, to clarify, the NGK vs stock plug issue is on my Sporty.

 

I believe in indexing plugs.
Its a pain but only minor,worst part is finding the washers but NRHS sells them
The late Sportster does not have a knock sensor or if it does it is not the ION sensing type as I have a 2012 "48" and it has 6R12's in it factory
I like NGK's and the correct plug is a DCPR7E and they run about 3 bucks each the DCPR7EIX Iridium will run you about 8 bucks each

 

http://www.nightrider.com/biketech/hdsparkplugs01.htm