It's not weird at all. The way an injector works has been posted 100's of times on probably every forum. You need a certain pressure differential between the input and the output on the injector for it to open up and inject soap. When you use a bigger size injector the back pressure a longer hose creates, shuts the injector off, because a larger orifice means less pressure on the input so the difference isn't enough. A smaller injector size insures that the difference in pressure is always enough to open the injector even with a lot of back pressure that a longer hose creates. Just remember to take the injector off or make an injector bypass, when you are using a surface cleaner because a smaller injector causes your unloader to bypass flow that you want and need.
That's a lot of hose!
