hi there...

you can alter the aircraft.cfg file to increase the amount of fuel you carry

i'm not sure if this applies for CFS, but  it's worth the shot

open the aircraft.cfg of the plane you want to edit
find the section called  [fuel]

there are listed all the fuel tanks of the plane. each has five numbers

the first three numbers is, i guess, the position of the fuel tank (XYZ coordinates)

the fourth one is what you're looking for... it's the amount of fuel this tank can carry

the fifth one i don't know what is... ::)

here's an example (this was taken from fs9, i hope its the same in CFS)
                   
[fuel]                                                          
LeftMain=0.0, -6.45, 0.0,  360, 0
RightMain=0.0,  6.45, 0.0,  360, 0
Center1=0.0,   0.0, 0.0,  250, 0
Center2=0.0,   0.0, 0.0,  250, 0
fuel_type=1
number_of_tank_selectors=1      
electric_pump=1

find the line for the drop tank and increase the amount of fuel it carries... that should do it

oh and remember to back up your original aircraft.cfg

hope this helps

c ya

Moach