In my series 6 build I had the main fuel valve mounted on the center console right where the build manual stated to place it. As I was manipulating the flap handle I noticed that my finger tips would always bump into the tail end of the plastic valve handle with the handle in the ON position. My first thought was to just saw off the tail of the plastic handle but I finally decided to move the valve forward on the console by 1 1/2". That eliminated the interference. in the attached picture you'll have to image the flap handle in my hand but you can see where the original position of the valve would be. I eventually plugged up the original hole in the console by riveting in a small backing plate of aluminum sheet behind the hole and then filling the recess with epoxy filed flush with the surface. This may be something to consider for those of you that haven't got to this point in your build yet or someone else who is annoyed to jammed fingertips.