Mercruiser 5.7 Horizon Draining Issues

[stormyj]

Hi all,
So, Im draining my blocks, closed system, for winter and pull the blue plugs from raw water side. Top plug, fuel filter box, water distribution housing, and there are two more plugs under the starboard side of the motor, on the raw water pump I believe. I do have seacocks supplying water to the motors, but even with the seacocks closed, water just keeps coming out of the water pump. I read somewhere that the impeller is between the blue plugs, so pulling the engine side plug will drain block, but not allow seawater to enter, pulling the other will let seawater to continue to come in. But with seacocks, I wouldnt think that would be a problem. Yes, the seacocks are closed. Any idea why the water still keeps coming in? Im pulling the boat on monday so I will take the seacocks apart and see if they are closing all the way. I thought that might be a problem. Any help would be appreciated.
thanks

 

[alldodge]

Serial number?
Pic of your seacock and water hose routing?

 

[Scott Danforth]

if they are raw water cooled, the small lines from the water distribution manifold to the block are most likely plugged

 

[QBhoy]

I’d suspect you might want to make sure the sea cocks don’t have the quote common issue of being seized, with the internal valve spindle sheared. So you think they are closed by moving the handle a quarter turn…but it’s only the handle that’s moving. Worth checking, if you can. Could perhaps try clamping the hose with vice grips or pipe clamp to see what happens