To me fresh water and raw water mean the same thing. There is closed and open cooling systems. I'm thinking you have closed cooling so your manifolds are cooled by antifreeze, and the risers and elbows are cooled by raw/fresh water. The reason being is antifreeze can be circulated thru a manifold (in thru the bottom and out thru the top), but there is not a second connection to bring water out thru the top on the riser.
Hi alldodge, Thanks for your reply.
Your are correct. When I say fresh water, I am referring to the antifreeze mix that circulates in my motor and exhaust manifolds. When I refer to raw water, I mean the water picked up by the thru hull fitting... also, there is a threaded hole in the 3" risers blocks for a hose fitting...
There is a fresh water hose going to the top and the bottom of the manifold. This is obviously how it circulates the water through it. There is also a fitting for a hose fitting in the side of the 3" spacer. I would assume you move the hose fitting from the top of the manifold, and install it in the side of the 3" riser block. Put a plug in the top manifold hole, and switch around the gaskets on the spacer block (yes with new ones)
Is this not accepted? Safe? I don't see why not, but am so puzzled as to why it wasn't originally done on this motor..
Can anyone shed some light? Or confirm it's ok to run my 3" spacer blocks with the fresh water running through the manifolds/motor.
