Sparkplug question

[motorking]

I use the NGK Iridium spark plug in my 08 Softail with no issues. No codes etc.

Have had many bikes over the years and ran NGK Iridium plugs in all of them. They made the most difference in the old point systems as they provided a better spark.

I agree with you comments on iridium fine wire plugs, that said, you can get the same results using a Autolite Iridium plug for 1/3 the cash outlay and be putting an american made spark plug in your american made bike

 

[cycleman11]

From what I understand about the Iridiums - what they actually do is slightly increase the timing, due to the more efficient spark.

That would explain the slightly smoother idle ( others report , I've noticed it as well) & slightly better performance ( shown on various dino tests ).

My only concern is that after a recent 300 mile ride I pulled the plugs and noticed different colours based on the plug being in the front or rear cylinder. The stock plugs don't show this. The Iridium rear plug gets a lighter colour which was also the way Autolite's worked in my previous BMW.

I've put a new set of stock plugs back in and off for a weekend ride ( in the rain ) so we'll see. The stock plugs do make the engine idle slower.

 

[Jack Klarich]

The great spark plug debate comes and goes, kind of like the oil debates, I say what ever makes you happy. I think OEM HD plugs are just fine they are manufactured to Harley specs and I have never had a problem with them. If I did not get The SE plugs as a gift I would have kept my stock plugs in, There was NO noticeable change in the performance. Like Bubbie I have had tried them all and most SUPER plugs are a waste of money, once you light the fire the rest is history:s