I have a 2007 FLHX 113 CI controlled via Powercommander 4 / USB.
The teeth on the transmission pulley were changed from 32 to 30, by the former owner.

According to the odometer compared to my car the same distance traveled was 6 tenths of a mile more on the Harley, over a 7 mile stretch.

Doing some research I discovered that the ThunderMax Self Tuner has software menu options for this modification, but don't have the spare $ at this time.

Any suggestions besides changing pulleys?

 

Call fuel moto or get a power vision tuner.

 

Baker has a speedo calibrator that you install in the deutsch communication harness between the trans and the speedo. It has an up and down button to calibrate the speedo. I have an earlier dakota digital one but havent tried it yet, as I havent found the connection yet. I think its under the battery housing frame, but Ill get to that eventually.
I have the same mod and my speedo is 4-8 mph off depending on speed. I think the cost is about $130

 

There are several different add-on units to calibrate the speedo, Dakota Digital makes one also, as stated above DJ PV has the ability as does the TTS tuner, most of the add-on ones are $100+.

 

Thanks folks , this gives me a starting point....