I believe I've figured out what's going on with my 2010 FXDC. I had no issues with the bike at all in 3000 miles of riding since purchasing it. I recently did an oil and filter change on it and my first ride out with it I noticed that it seemed to be underpowered and struggling to maintain speed. Especially at higher speeds. Upon returning home I discovered the engine was MUCH hotter than normal. I checked the oil to make sure I hadn't accidentally underfilled or overfilled it and the oil wasn't even touching the dipstick. I added oil until it almost reached the full line (about 2/3 quart) and took it back out for a short ride. I once again checked the level upon returning home and it was 2/3 quart OVERFILLED. I removed a half quart to get it back down to the full line. Since then I've taken it on a few short rides and continue to see sporadic oil levels when checking, loss of power (like I'm dragging extra weight), Very hot engine temps compared to before changing the oil, and most of all, my mpg has dropped from about 48mpg to about 36mpg. After much research, these are all classic symptoms of sumping. What could have caused my bike to start doing this after changing the oil and filter, and more importantly, what do I do now to actually fix it? I can't seem to find ANY info on that at all. If you can offer any help or suggestions I would greatly appreciate it!