Low tech solution follows:

Seal the filler cap. Plug the fuel line.  Blow up a balloon and attach it to the overflow vent.  Take a squeeze bottle with water and dish detergent and apply the solution on all glue joints and bolt holes. Observe for bubbles. It really does work.  The bubbles appeared ever so slowly on my experience. The small bubble took about 60 seconds to develop.  That is a small leak.

Smiley

94RJ