The first thing to understand is the AN650 is NOT aerodynamic. So many things dirtying up the air flow. The front finder could use a reshaping, right behind that is a huge parachute of a radiator intake. The windshild, another parachute. The mirrors, sidestand, exhaust pipes, centerstand are all hanging out in the airstream. Then there's the rider.
Tuck all that above into a form fitting "Dust-Bin" fairing with a tapered tail and I bet the same bike gains 20 MPH and 15 MPG.
Maybe have Delta Cams in Tacoma WA grind some hotter cams. Then the cone type cold air intake. Aftermarket pipes. Add a Power Commander to adjust fuel. A NOS kit.
Bigger rims and tires. Better suspension.
Whats this all add up to?