Thanks Rob for looking into this. I agree we need to work together to get this solved; it may be an irritation not worth worrying about, or it could be a very serious problem waiting to happen.
To answer your questions:
-- My aircraft is a Kitfox Super sport, built in 2011-2013. The other two aircraft in my area that I refer to as having similar issues are also Kitfox Super sports built about a year later than mine. We all have the Rotax 912ULS engine with nearly identical fuel systems.
-- We all use the Rotax fuel return restrictor #35.
