If raw water cooled there is an impeller in the outdrive. If fresh water cooled there is an engine mounted pump and an impeller in the outdrive. On the motor is a engine circulating pump. All are necessary to keep a cool running engine.
Ayuh,.... As BD said, the impeller delivers all the water, 'n the circulatin' pump on the front of the block, circulates the water, only in the block...
