Hello everyone, <br />I have a 4 cyl 153 cu. in. 120 hp mercruiser (SERIAL 1830111)with type IB sterndrive (SERIAL B 1927986). My question is about water flow while on the muffs....will water only flow up the "leg" and through the intake hose if the engine is running? or with pressure from garden hose should water be making it up to the riser (when engine is stopped)? I had an overheat and plan to change impellor, but wondered if water only flows while motor is running. Also, when wintering (adding antifreeze) can I just remove the hoses and pour antifreeze into water distribution housing and look for it to appear in relief valve? Is there a right direction to pour in the antifreeze? concerned about filling cylinders. <br />Thanks in advance. <br />Sam