This is a strange problem because if I read correctly you said that the fuel filter is going dry although the tank has a good vent drilled in it and has a clear outlet
I would suggest
1- that the tank be again removed and thoroughly washed out because that could be a piece of floating debris...
I have to tell you to run don’t walk from this model I had it since it was new with that exact engine and it was constant electrical problems from the third year forward.. I can tell you is that there was a diode instead of a rectifier to turn ac to dc (it was the cheap way to do it) and that...