make dropdown menu close faster

I have a menu system that has two levels. Main menu items that have some children.

When I hover over them, I get the preferred behavior that the menu drop down occurs.

However, when I leave the menu and go to the next one the previous dropdown delays it closing until both menus are visible and this is not the behavior we are after.

Does anyone know where the javascript or other code is that controls this behavior? Or does anyone have a suggested fix.

See attached image to see what it looks like .