The more I read on the various forums the more I'm mixed up. In 2011 I bought a new '96 Road King. Ran it for one year and thought it was excellent, smooth, linear etc.
Next year I got it bored to 103" and added 204 cams. It was far quicker but didn't run quite as smooth down low. Ran that for two years. Then went to high comp 107 with heads and TR590 cams, (124/121), went a lot faster but ran horrible down low, around town manners were bad. Crank failed right away. Got it rebuilt with Darkhorse etc. Then it needed another dyno session so this time I took it south to a dealer in Oregon and it again ran perfect above 60 mph but still, horrible around town, a real helmet rocker, after sitting hot it will chug around town until I got back on the throttle on the freeway etc. Definitely a right hand build.
Now my new basically stock bike with only Fatshots runs smoother than anyone could imagine, smoother than any one of my previous forays into performance work, from what I read makes about 95/75 in stock configuration but gets far less mpg's than my 124/121 combo did, I mean far less.
Now if they are supposed to run lean and hot, (not my findings so far but it hasn't been hot out), wouldn't it get more mpg's than my built motors got?

 

Sorry to hear of your troubles. The around town bad manners were simply bad tuning on your 103/107" builds. A stock bike should be well over 40 mpg on the hwy, if it's not, see your dealer. He should be able to find out why.

 

We have a 2014 and 2015 Limited with stage 1 on each and average 45 mpg. A few 100-150 mile trips around on back roads we averaged 50 mpg. Both bikes have Dynojet Power Vision tuner and auto-tuned a few times.

 

For what it is worth I have a dyna with a good 95 incher in it. Ran 12.04 113mph at dragstrip with a 190lb me on it. Gets 50+mpg last I checked. Perfect around town.600 + lift cams all home built motor. My 2014 limited gets around 40 mpg all stock with only slipons. My thought is the motors with more hp just breath better and don't work as hard. Granted one is a dyna and one is a big heavy tank. Love em both.

 

The best I've ever gotten in it's "1300+ brand new miles" so far is 40.
82 mph on the freeway for a smallish trip on my island, netted me 33.
So they say new Harley's run "lean", to me this is running richer than snot. I understand why one person who responded said that a built motor works less and I can totally see that.

 

My 14 SG with Street Cannons, SE Intake, and SE tune for stage 1 averages 35mpg across the board with stop and go in town traffic and 85mph cruise speed on the highway....

 

I honestly didn't pay much attention until I got the FP3. Now I average ~44mpg. For the most part, I do about 2/3 of my miles on the highway. I don't run it like a bat out of hell, but I don't baby it either. I run 70-80+ MPH on the highway. I haven't run it on a dyno at all, but I can tell it runs a tad cooler (running Amsoil as well), and the throttle is much more responsive.

 

Give it a chance to break in,, this may be part of the problem. I think I only got like 200 miles on my first tank, (before the low fuel light) and I have a 6 gal tank. Now it pops on around 240 if I'm not mistaken....

 

Yeah, I'm doing about 45mpg, Stock SGS motor with no cat, stage 1 pipes and AF, and FP3. Probably could do better but I run it in the higher end of the RPM range and I'm throttle hand heavy, lol.