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Sea water cooling flow issue

S

sentec

New member
I have a 2000 7.4L MPI Mercruiser, Bravo 1 Sterndrive with an open sea water cooling system. Recently lost the sea water pump impeller. I removed the pump and wanted to flush the intake line while it was apart. Attached a hose and flush ears to the stern drive inlet and attempted flush with engine off. There was absolutely no water flow. I would expect the intake to be wide open with water pouring out of the pump inlet hose. Is there an automatic valve or something that blocks flow while the engine is off? Or is there some kind of blockage?
 
First, Try back flushing vs the way you did it.

Bravo transom assemblies at the water in connection (hoses from drive to transom and from inner transom to impeller housing) use what I call a pinch method to secure the two hoses.

There are no barbed fittings and hose clamps if I remember correctly.

The area around the junction of the pinch/hose meeting location at the transom assembly corrode horribly and pinch the hose itself and can severly restrict incoming water flow.

This has to be inspected and the scale/corrosion removed to allow normal water flow.

I am not saying this is your issue but be aware, it may be......it is very common
 
Thank you. Does the transom assembly have to be disassembled or removed to access this? It is very difficult to access from the engine compartment.
 
When I have worked this issue I had the engines out so I removed the transom assembly to work on it on a bench.

Maybe some others who have worked this issue more often than me will respond with their method(s) to at a minimum, be able to inspect this without major disassembly.

I would think, The drive has to be pulled off and possibly remove the gimbal housing pivot bolts and then remove the water hose that connect to the outer transom pass thru to get a look. It may require a bot more disassembly but for me its been a while so wait for others to chime in.
 
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