coolant water not squirting constantly

[bouncermike2000]

Shouldn't the coolant water always squirt out the back? I have a 1996 Mercury 90HP 4-stroke outboard. Does the coolant system rely upon an impeller or a pump to provide pressure? I hit a stump in shallow water and the engine died with a very audible thump. This may have damaged an impeller huh? Sheared the key perhaps. The prop runs and the boat has power; however, there is a bit of a "wobble or shimmy" felt, sometimes accompanied by strange noises coming from the prop area.