Anti-siphon valve

had some problems with engine losing power intermittently at higher speeds with weight on the boat. I pulled the antisiphon valve and found what looked to be some small pine needles that must have some how fallen in to the tank. The spring load on the check ball bearing seem to move freely but after I cleaned out the needles it seemed kind of hard to blow thru the valve. I have 2 questions. 1. Should it be kind of hard to blow thru the valve? Or should I be able to blow thru with out any restriction? 2. Is it possible that those little pine needles were causing the hesitation at higher speeds?

It should be very hard to blow through, you want that ball to stop fuel from siphoning from the tank in the event of a fuel line rupture.