splashandburn

I have twin 500 EFI's that have freshwater flushes installed. The boat is being used in salt water and I want to be able to flush the motors after I use it. The problem is that I can't get the boat out of the water to flush them. I can hook a hose up while at the dock and run the motors but is this really flushing them or am I still pulling in salt water thru the drive intakes?? Any comments would be appreciated.

TomR

splashandburn,

You could install a three way shut off valve, before your raw water pump, in place of the "T" fitting that you must already have for each motor. This would allow you to shut off the sea water and allow fresh water to enter thru a house fitting.
Just don't forget to switch back before you go boating!!

FlyFast

TomR,

I have a tee going to my bravo raw water pump. I can close the sea cock to the trhu fitting and open the valve to the hose fitting.

The problem that I have is that the hose will get sucked flat and I burn up impellors.

Has any one had any luck with this type of setup? The bravo raw water pump will suck more than the hose can put out. I am beginning to think thay you need a loose conection so that air can be sucked in with the water.

I would like to figure this out and just put a hose fitting on the back of my boat flick a couple of valves and flush.

Thanks

splashandburn

Does it do any good to just run the hose with the boat in the water??

TomR

When you say it sucks the hose flat, are you referring to the hose in the boat from the fitting to the valves??
If the answer is yes, there are two things that come to mind:
A) Replace the hose with a more rigid hose, for instance marine hot water exhaust type.

B) The source for your water is not giving you enough water pressure. This was a problem for me until I had a new water main installed feeding my house.
If this is at a marina check with the management and ask that they make sure that all of the valves feeding out to the hose are fully open. Obviously if this is your own property check your source.

The set-up that you have should work fine provided that the proper type of hose was used in the boat!

FlyFast

Tomr,

It sucks the garden hose flat. I have bought a better hose.

With a normal flush fitting the water sprays all over and some air can be sucked in. With my setup the garden hose makes a tight connection to the line that goes to the bravo raw water pump. The raw water pump at idle will suck more than my hose will put out.

I would like to transom mount a fitting so I could flip a couple of valves hook up a hose and flush. My anwser might be to leave the hose washer out of the fitting on the transom so a little air will be sucked in rather than the hose sucked flat on a low pressure line.

Somehow the factory washdown hose adapters must deal with a low pressure hose. Does anyone know the code?

Thanks

Wally

FlyFast.....heres a solution that could work for ya. You would still need to get inside the engine compartment to switch a vale but it should keep the hose from collapsing.
you will need two shut off valves....two "T"s some hose and the water fittings

what you would need to do is install a on/off valve between the water pickup and the seawater pump. The install one of the "T"'s between the valve and the seawater pump. From the "T" you take you freshwater supply hose and route it to a place either inside the engine compartment or some place outside the boat where you will be hooking up your garden hose. somewhere thats convenient for you, you will need to add the second shutoff valve and between that valve and where your city water comes in you will add the second "T" From that "T" you will probably need about a 1/2" hose running to a water dump fitting exiting to the outside of the boat.

So the way this would work is when you wanted to flush the engines you shut off the main valve (#1) and open valve #2. this way the seawater pump will not be drawing in any lake/ocean water. you turn on the garden water supply and when it starts "pissing" out that water dump fitting you can start the engine up.....this way when the engine starts and tries to suck the line dry the water dump fitting will act as an air supply thus allowing the garden hose to stay open and keep water flowing. heres a very crude drawing i did and scanned in....Hope it comes out in a good size and hope it makes some sense.

FlyFast

Wally

I like it. I will try it.

Thanks

Liberator21

Because I don't have a water supply where I keep my boat, I use a 5 gallon jerry can rigged with a valve and a hose the same size as the inlet hose to the pump. It draws like crazy from the container, and the hose won't collapse. 5 gallons is enough to flush a small block. Don't know about a big block. The jerry can is vented.

FlyFast

Liberator21

I have thought about using my 9 gallon fresh water tank. At least I would keep my fresh water tank flushed.

This is the deal:

I have a thru fitting with a 1 1/4 shut off valve. There is a tee on the thru fitting and one side has a 1 1/4 inch hose that runs to the bravo raw wter pump. This hose is wire reinforced marine grade and will not suck closed.
On the other side of the tee I hook a garden hose.

Now here is where I need someone who understanda fluids: I turn on the hose and the 4 feet of 1 1/4 hose fills with water to the raw water pump. I start the motor and the raw water pump at 30 psi will suck the 1 1/4 hose dry and then starts to draw from the 3/4 garden hose at 60 psi. The suction is so great the hose will collaspe and my raw water pump will burn up if I am not very careful.

I have gone to a globe impeller which is suppose to run dry for 15 minutes. I wonder how long the housing will take it? My boat is full closed coooling so I don't worry about hot spots in the heads.

I like wallybigblocks idea and just attach a tee to the hose inlet and vent it so it can suck air rather than sucking the hose closed. I am going to give it a try.


Thanks