The bellows need to be "burped" at each launching. If run dry, heat , noise(squeeling) and wear(dust) will result.
But wait! The one pictured is water
injected, so the next thing I would look at is shaft/ engine
alignment. A stuffing box can put the shaft out of wack. There is usually only one bearing , the cutlass in the back, and, being in the middleish of a shaft usually, the sb can push a little on the shaft,
Or, if the shaft is oscillating, the licks will show up right there.
If you loosen it up , remember there are 2 set screws in each hole, they are "piled" on each other.