Fuel Flow Scalar

My favorite plane is the [glb]Beech King Air 350.[/glb] I am currently flying RTW with it, and at the start, I had to make an emergency fuel stop after only flying [glb]384 NM!!!!![/glb] The Beech stats online say the bird has a range of around 1,800 Nm, so I changed the fuel flow scalar from 1.0 to .17 to get it in that ballpark range. Now the fuel guage reads FULL after traveling 1500 nm! How can I fix it to go down realistically? I saw somewhere that if you up the thrust scalar, it will, but I don't know..... TIA Alex