Spark Plug X Reference Chart

[glider.]

Here's a handy cross reference for Harley plugs.
Be advised that a change to a different plug or plug wire than stock could result in setting a code in the Delphi systems of later year Harley's from the ION sensing system that uses a set resistance to detect knock in the engine.

This is not usually true if just going to a colder heat range.

Usually a change between the HD plug and Champion plugs will set no codes.

Also here's a handy reference for all plugs in different bikes.

Spark Plug Interchange Guide

 

[2003FLHPI]

Is there one plug better than another?

 

[glider.]

I would use the stock plug because of the ION sensing. If you change to a different type plug the ION sensing system will not work properly and pinging/detonation will not be detected and dealt with through the resistance in the plugs.

 

[Bud White]

I was just reading this mornign and saw this
(Usually a change between the HD plug and Champion plugs will set no codes.)

Id bet that because Champion makes the HD plugs they sure look like them esp the gold plugs

 

[glider.]

I believe you are correct Bud!

Remember that Harley builds bikes but not necessarily every part that goes into them.