RE: Walbro screen filter ?
After a few engine failures: When that little mesh filter gets clogged, the dirt in it compacts so fast that you hardly have time to react to the symptoms
I run a felt filter in the tank kneaded in petrol and flushed well before fitting. This filters so well, that the screen in the carb stays clean.
I use a three line tank. One for filling (with fuel dot), one to the carb, and one vent line.
My filler bottle has a paper filter on the outgoing line. Better would be to have that filter in the fill line inside the plane.
When mixing fuel, the fuel is strained through a funnel filter.