Mercruiser cooling explanation

[jetsetc5]

I got a 1989 268 sundancer 27' searay with 7.4 Bravo 3 (saltwater use). Repowered in 1996. Can I run this boat out of the water? It has a raw water pump with thru hull pickup. I also have the flush master system. I dont seem to have a strainer at my thru hull. It also has the oil/pwr steering cooler. Do i need to put the ear muffs on the out drive as I would on a outboard?. Is there a way to stick a water hose at the raw water pickup or can I substitute the flushmaster water(which I can stick a water hose on)? I just changed the raw water impeller and am ready to check things out. Also the boat has been sitting since hurricane Ivan...anything else i should do? Any help would be appreciated. Frank

 

[Don S]

Re: Mercruiser cooling explanation

You need to put water into the raw water pump to cool the engine while running.<br />Most of the flushing systems flush the system ok, but are hooked up after the raw water pump. If you use it that way, you will burn up your raw water pump impeller and plastic housing $$$.<br />Without seeing how your system is set up, I would be afraid to say for sure how to hook it up.<br />I have made fittings to hook a hose to the thruhull straineer with part of an engine flusher., but would suggest you have your local Mercruiser marine dealer actually SHOW you how to hook it up. It would be cheaper than replacing the pump.

 

[milkyway]

Re: Mercruiser cooling explanation

Whatever you do, just remember that the impeller, in addition that it pumps water from the sea or lake, it utilizes water as lubricant. Without water, you will destroy the impeller. So fully understand how everything it set up. Or just hook up the muffs on the outdrive and you can't go wrong.

 

[waterone1@aol.com]

Re: Mercruiser cooling explanation

Milky, he has a thru- hull water pickup with a belt driven water pump, muffs on the outdrive will not work. Jetset- they make two different types of "muffs" for this aplication, one type is a half muff mounted on top of a telescoping pole that pushes the muff against the hull. The other type uses a spring loaded hook that clips to the grating on the thru-hull. Any Sea Ray dealer should have them.

 

[jetsetc5]

Re: Mercruiser cooling explanation

Thank you guys. I will see if I can get a thru hull water hose muff and also hook up my outboard type muffs to my stern dreive water pick up. Thanks again

 

[jetsetc5]

Re: Mercruiser cooling explanation

One last question. My seloc manual states that the water pump for the lower unit is belt driven off the engine. Can I assume that since I have a belt driven sea water pump that there is no need to install ear muffs on the lower unit when starting?

 

[waterone1@aol.com]

Re: Mercruiser cooling explanation

Jetset, If you have a Bravo III, with a thru-hull water pickup, there is no need to connect muffs to the drive...there is no water pump in it......get your water to the thru-hull.