I recently did some reworking of my GL1500's fuel lines, etc. In the process, I made a modification to the mount for the OEM Automatic Fuel Valve or "Vacuum Petc0ck" that sometimes develops a leak due to aged diaphragm or seal rubber cup. The mount is attached to the spill tray by a screw from underneath, so it's a PITA to get to, but if you remove the gas cap, if you have the radio loose, remove the vacuum hose, the drain tube too, you can get the drip pan up enough to get the bracket loose. Some simply leave that screw underneath out so they can get the AFV up … and that works.
I chose to mod mine so I can loosen the two lower screws and pull the AFV up so I can remove all 4 screws and service in oplace, even leaving fuel hoses in place. the way I notched it, insert one side, slide right, other drops in place. I have a really short P-2 bit in a 1/4 drive ratchet wrench that lets me attack the lower two screws.
This thread is just to show a drawing I made of notched holes. Maybe helps someone?