Have you ever re-assembled and installed your carb only to find out that it leaks? Could be it's assembled incorrectly, the float won't float or is out of adjustment or the needle is damaged or.... Sometimes the carb is easy to access. And sometimes it's not. I found it a lot easier to just bench test my carbs before installing them and I built a small stand out of plywood scraps. adding a fuel container on top to deliver gas through a fuel line to the carb. If you do a lot of carburetor work, this could be a useful device for you. Of course, if you only do 1 carb in a blue moon, it's probably more trouble than it's worth.
