I had a built up 04 E-glide that liked to ping a little in the heat. I had bumped the compression up. I ran two heat ranges cooler for many years with great results. I would have to run a little octane booster for temps over 100*. I always ran Autolite plugs.

 

2005 or above you need to run a HD plug due to the computerized system in your bike you can go with a colder plug but you need to buy them from HD or you will mess up the cpu in your bike.Just my 2 cents!

 

I have heard that before. I would think that as long as the resistance is in limits, it shouldn't matter, but this is why I am hesitant about trying a different plug. Maybe someone else can confirm.

 

Who makes the OEM plugs? Autolite?

 

That's complete BS. Who the hell told you that? An HD dealer? HD plugs are nothing special.

 

your bike has an anit-knock system that relies on elctrical values of a specific brand and model spark plug. you cn use a stock plug or an exact equiv of the stock plug. but deviating from that will screw up your anti knock system and if the right anti knock senerio occurs, engine damage could result.

 

It's not complete BS, but its not completely accurate either. I don't think you can actually damage the ECM by using an other than OEM plug, but the ion sensing function is designed around the HD plug characteristics, so an alternate plug may not work correctly. I know there are some really smart electronics guys here that probably know or could figure out the critical electrical characteristics and the values required in a plug, and a bench test to validate a given plug's fitness for the ion sensing application. What say you electrical engineers.

 

I've run Autolite 4163 with no problems. These are one heat-range lower than stock and don't interfere with the ion-discharge knock-sensing function. Cost is about $1.50 each. The only problem I had with these was the screw-on cap that tended to unscrew in time, leaving it in the wire with no solid connection to the plug.

 

Champion RABHC for the stockers, not sure about the Gold and others.

 

Haven't had oem plugs in my bike for about 20k miles. 07