Fresh Water Cooled Engines...Riser/Manifold Replacement?
 

I bought a "new to me" 2004 280SC Powerquest boat earlier this summer. It was always used in the great lakes, it's never seen salt/brackish water. Both 496HO engines are fresh water cooled as well. The boat does not have a fresh water flush hook up. I keep the boat on a lift and can not get to the outdrives to flush the engines after every use. Should I have a fresh water hook up installed in the engine hatch area or should I not be concerened? My mechanic said that I will be fine since both engines are fresh water cooled and the only thing I would be flushing is just the risers and manifolds, if I had the fresh water flush installed. I've never had fresh water cooled engines before and I'm wondering if I will see longer life out of my risers and manifolds? Let me know what you guys think. Thanks

I'd get a fresh water flush installed ASAP, if it were me...... and a new mechanic! There is more that just the manifolds/risers, what about the heat exchanger, and the outdrives?
Dean

I agree, I was leaning towars installing a fresh water flush and think I may do so anyways. I'm not a mechanic, but if a fresh water flush is installed will it flush out the outdrives and the heat exchanger? I think what my mechanic was saying is if I installed a fresh water flush that the only parts that would physically be flushed out are the risers and manifolds. Is that not true?

Your engines have what is referred to as "Closed Cooling" which means they are cooled by circulating antifreeze/coolant in the actual engine. They are not fresh water cooled. The antifreeze is cooled using a heat exchanger which is similar to a car radiator. Basically everything except the actual engine still gets sea water circulated through it. In a salt water environment, you need to have fresh water flushes installed and use them after each use.

Griff, thanks for correcting me. I don't know why as I keep referring to them as "Fresh Water Cooled". Thanks for the suggestions guys as I will add installing fresh water flush hoses to my spring "to do" list as well as a new mechanic :)