Figured I'd share what the part numbers are of the NGK Iridium plugs most commonly used in the sportster from what i've read.

DCPR7EIX - factory interchange with a 7 heat range, stock replacement upgrade plug.

DCPR8EIX - Same plug as above but 1 Step colder!








Also, I took the original factory Harley plugs and decided to Side Gap them, which is unshrouding the center electrode to expose the flame kernel better.

I'm gonna install these in a little bit and go for a ride. This is just an experiment on my own bike. Plus, I'm skeptic yet optimistic on what will happen since I already have DCPR7EIX plugs installed.

So those who will say nothing will happen, please read above again...lol.

Factory Spark plug with Side Gap mod. Gapped to .039

 

Interesting, I just looked up side gapped plugs, sounds like there is some evidence it works. Look forward to your formal evaluation.

John

 

Honestly I may not try the side gap plugs because I just put in 1 step colder DCPR8IEX ngk iridiums and with the SFI valve adjusted 3/4 open. it's running really well on stock tune. so I'm probably just going to run it how it is for now until I get the Powervision.

 

i had to gap my iridiums plugs stock replacement ones. they had a really small gap. i had to open them. even thought it said pre gapped. I contact NKg and they told me to gap it to stock gap i needed

 

I have mine gapped at .040 Manual states between .038-.043

So far its running great, no issues.

I have a spare set of DCPR7EIX now that I may try and side gap just to see what happens with the iridiums. Maybe...

 

if it runs good leave it. some people on here have had issues with iridiums right off the bat.

 

Seems like most people who've had issues with iridiums are carbed bikes. At least thats what i've gathered from reading on the forums.

Also, making sure to gap the iridiums correctly is sometimes overlooked as some people are worried about breaking the electrode. Its pretty simple, just by using some small needle nose pliers and some feeler gauges.

I don't really like those coin shaped plug gappers.

 

i used the coin and needle nose's but i took my time and got my .04

 

I installed the DCPR8IEX in my all bore 107 and my ECM didn't like them. ION sensing issues. Threw a code and i ended up going to the SE plug made for the high compression.

 

I don't think the Sportsters come with Ion Sensing, I could be wrong though. I have a 2017 Iron 883, The 2014+ sportsters are canbus as well.

I haven't had any issues with the way the bike drives or responds etc.