I too fuel via an extra fuel line too bypassing the felt clunk. One of the resons is that by doing this I reduce the risk of flooding the engine if the solenoid is broken. Also I like the fuel to always pass through the felt in the same direction at all times. I use the felt clunk purely as a bubble trap. Still if there are large FOD in the fuel it will be cought before messing up the fuel pump. So even if not seen as a filter it can help. Works very well for my micro turbines without any hopper tank.