I have the same complaint. These things are a joke when it comes to fuel mileage. I don't know why they went to fuel injection if this is what it does for you. I think we are hosed - how are you going to adjust an EFI?
I have a '94 700 wildcat (carb). It uses half the gas the pantera does. It also gets better mileage than a Yamaha RX1 four stroke.... I ride with them all day - most of the time in front.