Listers, Does the washer under the float bowl hold down nut seal? Or is that a vent? Bob Haskell '60 AH3000 BT7 (big project) '62 AH3000 BT7 (smaller project) '64 Mini Cooper (small project - by definition) '68 BMW 1600 (first car - project) '80 MBG LE (running?)