How much fuel should be in my inline fuel filter?

[Levie17]

Just trying to eliminate a possible air leak somewhere in the system.

I have a clear plastic filter on my 2002 125

when I pump the ball, the filter is half filled, at idle there is only 1/4 fuel in the filter.

 

[GA_Boater]

An inline filter isn't filled completely when running, so what you see is normal.