Plain old stock HD plugs

 

I run NGK or Champion spark plugs. Champion actually makes the stardard Harley spark plug.

 

Yea, it is kinda like asking about oil....but since you asked...here goes:
First I need to let ya know that being down here in Florida, I ride my Evo to work most days. It's the SAME 100 mi (roundtrip) commute over the SAME roads at the SAME time everyday. Been doing it for 8 yrs. As a result, I have gotten to where I can pretty accurately predict how much gas she will take everytime I fill her up, and it will very much depend on how I rode her. It's sort of a game I play with myself and I can generally hit it to within a hundreth of a gallon or so. I know...I know...that's being waaayyyy too "****", but hey, I'm a scientist and I like to "know things".
Now that we have all that outta the way, we'll get to the answer:
NGK Iridium plugs are the only ones I've found to show a measurable improvement in mpg on my daily commute. It's a small difference to be sure, but I calculated the improvement (at today's ridiculous gas prices) paid for the difference in the cost of the plugs in the first 5,000 mi. I change'em out at 10,000 or so.

I don't Dyno my bike, so I have no idea what, if any effect they are having on horsepower or torque.

 

Just remember anytime you change plug manufacturer you need to chase threads because they have slight variance in threads of plugs.

 

I'm calling BS on this.....

 

I am waiting to hear from somebody running the Pulstar Pulse plugs other than the guy that sells them.

 

I put them in my bike around 5k miles.
Never noticed a difference in anything.
around 10k I developed a miss. After chnging the fuel filter, I noticed the front plug
had carbon at the botom of the insulator. The whole thing would spin in the metal
body.
I took it back and had it replaced. when replacing the rear it felt like it was stripping the threads (I ALWAYS use Antii-siezeand a torque wrench with plug socket). I pulled it out and looked at all the threads....no problems found.
When re installing the plug the threads broke off in the head(*^&^)!
The thread broke off at the point where the gasket is attached.
I took both back and got NGKs.

 

I run NGK Iridium in just about everything. It has always been a great performing plug in my cars, trucks and every motorcycle I've ever had. They cost a little more but I've never had one foul or fail to deliver.

 

Sorry just preventative maintenance that is old school from 60's.

 

Cross reference whatever you are using now to NGK Iridium and make the switch. Don't even gap them, just put them in and ride, and enjoy the difference.