Dads, I didn't see you mention a filter other than the in-tank-filter.A filter in the line is a necessity to catch the "where did that come froms?".I would have a large, transparent filter mounted AFTER the pump , in the coolest place.
The float valve finds the smallest particles to keep it from seating because it runs in a nearly closed tight position when the engine is not working hard and when it leaks because of a particle under the needle, it just clamps down harder on the particle.
A method I routinely use to clear an overflowing bowl ("float sticking")is to STOP the flow from the pump.Clamp tight or disconnect the pump inlet line, usually a pair of pliers will do it, while the engine is running until the bowl runs dry and the engine stalls or nearly stalls, then restore the flow to the pump and the tiny offending particle will be flushed from the now open float valve into the bowl where it usually settles into one of the bottom-of-the-bowl cavities and 10 times out of 9 is there until the next cleanup/rebuild while the float valve has been purged and a normal bowl level is restored.
