I have an 07 Road King and just did a typical Stage I with Vance & Hines Basic slip-ons, Screaming Eagle high-flow air cleaner, and a Power commander. Performance is a little better, although not as much difference as I had hoped for. Sound is great, but mileage went in the toilet. I just returned from a weekend trip from MD to NC and over 725 miles, I averaged about 35 MPG on the highway. Stock, my mileage was close to 10 MPG better. I don’t really care about MPG except for the fact that it really cuts into the bikes range between fueling. Sucks on the road trips to always be the first to need gas. Also, I have always heard that a PC improves performane and MPG

The stock bike appeared to run way too hot (lean), with the stock pipes blueing all the way to the bend at the footboards so I know it needed to run richer. Power Commander answers that need and it actually shows a little (very little) smoke at start-up. Starting is a little harder now and mileage really suffered. I'm wondering if I should lean it back out a little (tweak it) via the Power Commander.

I made these same performance mods (with a remap of the stock ECM instead of the Power Commander) to my 2002 Road King and did not suffer this loss of MPG. It also never got harder to start like this one. Is this all due to the Power Commander and if so, how much (and how) should I tweak it?

I really would like to get back to 200 miles between fueling for those long stretches of road out west where it might be 150 miles between gas.

Do you think that the PC just needs remapping (again)?

Any suggestions on improving performance and getting a little better MPG?

Any help is appreciated.

 

The three symptoms you describe, 10 mpg loss after Stage 1, smoke at startup and harder starting, indicate too rich. Have you also done a spark plug read? That should give you a good visual indication for what's going on too.

It sounds like you need to tweak your PC to the leaner side. I'd start with that first. A properly tuned Stage 1 setup should get you pretty close to stock MPG.