The flushing port

[Jp334400]

First time poster. I have a 2012 F115 with 80 hrs on her. I have been flushing after each use. Most times in fresh water use I just hook the hose directly to attachment port and let the water flow without the engine running. After salt use I run it on the ears. Last few times on flush port water flows everywhere except the pee hole. Everything works on the ears. I have tried blowing compressed air and all seems fine. I have excellent pressure as I live near the town water tower. What is the possible problems if any. Thanks in advance

[rodbolt17]

typically, a venturi effect at the T fitting on the lower ex cover.
its rather normal.

[Jp334400]

Soo don't worry about it. As long as water is flowing when the hose is connected to the port. Now remember with the ears all is normal

[rodbolt17]

yep.
look very carefully at the T fitting.
then read about "venturi effect" then it will become clear.
but its something we have seen since the 90's on the inline 4 four strokes.