Good question! I assumed there nothing more fancy then that on the BX's since the motor is small. But I do know there are 2 fuel filters. There is one underneath the chassis and its metal type and the other is plastic up near engine just before fuel enters the injectors. Since the 2 fuel filters look different and looks strategically placed, I assumed they both filters stuff differently. It appears that most of the BX's are like that.
I assume the plastic filter is for waxing issue when its really cold with untreated fuel, but the metal filter I am not too sure what it really does as far as what it really filters. maybe someone here might know ? Who has the WSM that might have the answer in it ?