After changing the oil in my iron which was pretty bad due to mainly short trips im thinking about changing my spark plugs too. I have the screamin eagle plugs in there at the mo cos thought they looked good! Lol. They are about 14 month's old and done about 2400 miles but as said short trips so probably sooted up. Im thinking this time fit ngk iridium as I had these on another bike and was impressed and I can get a pair delivered for equivalent of about $9 so not bad. Do you think these will be ok or clean my se plugs or use normal hd plugs?

 

I have used iridium plugs in the past. They worked well for me.

Most of the time I just use the stock HD plugs. I doubt that your plugs are sooted up (unless you have a carbed bike, then they might be), or need changing. The interval for inspecting is 10K miles and for replacing is 20K miles.

 

ok, might just take them out and check and clean them as bike is running good. Also been reading that should run stock hd plugs otherwise the anti knock wont work but i also have the 10mm se leads on mine and stage 1 upgrade so even if i changed to stock plugs the anti knock might still be not working?

 

There is no knock sensor in the Harley plugs. $1.99 Champions at NAPA will get you all the spark you need. A 10 mile ride will clean up your your plugs if they are sooted up but they're probably very clean.

 

I like E3 plugs run them in all my cars & both bikes. Made a noticeable difference in performance & mileage in my truck & car. Seems to make the bikes perform better but no change in mpg. Maybe just feels that way in the bikes but I know for sure in my truck they improved performance, mpg & passed smog with best #'s ever!

 

Sportsters have no knock detection system at all. That's where your tuner will need to change timing and have good ears to find the pings and so forth. Running se plugs are fine if you have them. I bought them when I had some chrome cash to burn up. As others have said stock HD plugs are fine or whatever equivilant you prefer.

 

I used the E3.36 for a tad over a year too. I use them in everything but the car and bike now. My high compression Husqvarna chainsaw was a pain to start with the stock plug. Now it rarely takes more than one pull to start it. Mowers and lawn tractors use much less gas now with them. Tractor took just over a tank to mow before, now there is gas left in the tank when Im done.

In the bike they ran awesome. I did notice better mileage with them in mine, but it was only about 3%. I switched to Autolite XS4164 Iridium a year ago though. The E3 was no better in sub 20F starts. With the Iridium plug starts down to 10F are like mid summer starts, also alot less fouling of the Iridium plug. If I were a fair weather rider I would still run the E3 and not even think twice about it. Great plugs.

 

Get the NGK Iridium plugs. There are 3 different ones that fit our Sportys -

DCPR7EIX
DCPR8EIX
DCPR9EIX

The higher the number, the cooler the plug runs. the DCPR7EIX would be similar to our stock plug. I suggest running the DCPR8EIX as it seems to be the middle ground of running hot (DCPR7EIX) which can cause pinging and running cold (DCPR9EIX) which can cause carbon buildup resulting in plug failure

 

Very interesting info.

OP: Pull the plugs and look at them. I bet you they look fine. Personally, on a bike like this I will use the Harley plugs simply because I know my bike likes them. I only experiment with aftermarket plugs on vehicles where the factory plugs don't perform well.

Definitely if you are installing a non factory plug, find reviews of that plug in your exact bike online first. Some bikes just HATE certain brands or types of plugs that should in theory work fine...so I avoid that guesswork by sticking to the factory plug, or by going with good advice like you got from BMCSteve.

 

Might want to check gap too when you pull them. I have seen plenty of brandnew harleys with one plug too tight and the other way too long.