Fresh water flushing

"I have a 1988 boat with twin

"I have a 1988 boat with twin 5.7 mercruisers, freshwater cooled. The sea water for the heat exchanger (which is leaking!)is taken through a thru hull fitting via hose to the sea water pump on the engine. Do I need some fancy kit to run this engin while not in the water or can I simply do the old hose in the buck of winterizer route. I ask because I have to winterize the engine and need to protect the block from freezing.

Thanks in advance."

"Sure. Just stick a water hos

"Sure. Just stick a water hose into the raw water pump inlet hose and fire her up. Do NOT rev the motor higher than 1,500 rpms for the raw water pump will run dry--the flow from the water hose is not enough.

That said, you still need to run the Pink Stuff through the rest of your system or you'll be sorry in the Spring. They sell plastic jug deals that you can use to put the Pink Stuff into the raw water pump inlet until it comes out the back.

Jeff"

"Jeff,
Help me out a little h

"Jeff,
Help me out a little here. If you have a heat exchanger then the system should be closed and the engine should have antifreeze / coolant in it at all times. This is the reason for the exchanger. Is this what you have?

If this is the case the only things needing protection is the seawater side of the exchanger the exhaust manifold elbows the seawater pump and the power steering cooler.
I can't see anyway of pumping the antifreeze through the pick up in the bottom of the boat unless you fill someones pool with the stuff.

This how I handle this type of system and I've never had any problems.
Disconnect the seawater discharge line at the T where it splits off to each exhaust elbow. Drain the elbows replace the plugs then pour a little antifreeze into the lines going to the elbows.

Remove the line from the seawater pump and the exchanger to make sure no water is left in them then replace the lines.
Remove the line from the pick up to the steering cooler. Cap the steering cooler and pour antifreeze into the line that was disconnected from the T until it is full. Replace the line to the T.

It is best to disconnect the line at the steering cooler from the pick up then cap the cooler and fill the system with antifreeze.

If you can't get at these lines then blow the system out with LOW pressure and then pour antifreeze into the line until it comes out of the pick up. Of course you need to place a drain pan under the pick up.

If the engine does not have coolant in it for some reason you need to drain and fill it with antifreeze along with the manifolds."

"Charlie,
I do have a heat ex

"Charlie,
I do have a heat exchanger with anti-freeze. I just did not know how to protect the seawater side. Thanks for your points. I thought maybe you had to pump antifreeze over the raw water side. I will drain down instead as descibed and fill where I can with antifreeze.

Someone else mentioned pouring marvel mystery oil down the spark plug holes to keep things from rusting. Any thoughts on that?

Thanks again,
jeff"

"Jeff:

Do yourself a HUGE f

"Jeff:

Do yourself a HUGE favr and run the Pink Stuff through the entire system until it comes out the back. Draining does NOT gaurantee that water pockets are eliminated, and just one of them will cost ten times more than the Pink Stuff! Drain the water from the manifolds and elbows FIRST, then introduce the Pink Stuff into the raw water pump--it will take several gallons--until it comes out the back. Then enjoy the winter (grrrr!)

The Other eff"