When non power shifting and you close the throttle in between shifts, yes they do close. Then it takes time for the out board to open again, by which it's time to shift again. And drag racing is all about not wasting time, like waiting for the out boards to open wide again. Things are different when power-shifting though . 6 pacs like autos. I run my 6 Pac bee without the springs for the secondaries, which seems to make it quicker when not power shifting. My car is more responsive with a 850 double pumper.