Weird, sudden AFR issue Proform 750cfm!

The AED I have has nylon type sealing washers for the squirters, as well as for the bowl/block screws. There are thin and some are much thicker but I've used that style for many sealing bolts/plugs etc on all sorts of applications and never had leaks. If they are thicker the thread (fine especially) engagement might be reduced, but if the threads are repaired they are what I'd use. I just sneek up on the final tightening, a slight snug beyond seating. Never worry about stripping things.