I recently bought a Fatboy from a local Harley Davidson dealer with around 20k miles. I been riding it for a week with no problems, except a little hesitation under full throttle. I noticed one time I went to pull onto a highway and it just stopped, I had to roll the bike backwards off the road, however, I started it again and rode with no problems. Yesterday I was riding and all of the sudden I had some weird erratic throttle, the bike would slow down, speed up, bog down, shoot off. It was like I was running out of gas. I managed to get where I was going and checked things out. I drive it again and it seemed ok, got to a gas station and filled up (It only took 2 gallons) and went home, on the way home it bogged down again once and then it was smooth.

It's an S&S carb.

What could this be? Is half of the softail's tank reserve? It seemed like the right half was empty or low.

This is my first time on here, so thank you guys for your help.